diff --git a/thys/CAVA_LTL_Modelchecker/SM/Impl/SM_Ample_Impl.thy b/thys/CAVA_LTL_Modelchecker/SM/Impl/SM_Ample_Impl.thy
--- a/thys/CAVA_LTL_Modelchecker/SM/Impl/SM_Ample_Impl.thy
+++ b/thys/CAVA_LTL_Modelchecker/SM/Impl/SM_Ample_Impl.thy
@@ -1,1413 +1,1412 @@
 theory SM_Ample_Impl
 imports SM_Datastructures "../Analysis/SM_POR"
   "HOL-Library.RBT_Mapping"
 begin
 
   text \<open>
     Given a sticky program, we implement
     a valid ample-function by picking the transitions from the first
     PID that qualifies as an ample-set\<close>
   context visible_prog
   begin
     definition ga_gample
       :: "(cmdc\<times>cmdc) set \<Rightarrow> pid_global_config \<Rightarrow> global_action set" 
     where
       "ga_gample sticky_E gc \<equiv> let
         lcs = pid_global_config.processes gc;
         gs = pid_global_config.state gc;
         as = find_min_idx_f (\<lambda>lc.
           let
             c = local_config.command lc;
             ls = local_config.state lc;
             as = set (comp.succ_impl c)
           in
             if (\<forall>(a,_)\<in>as. read_globals a = {} \<and> write_globals a = {}) then
               let 
                 as = {(a,c')\<in>as. la_en' (ls,gs) a}
               in
                 if as={} \<or> (\<exists>(a,c')\<in>as. (c,c')\<in>sticky_E) then 
                   None 
                 else 
                   Some (c,as)
             else
               None
         ) lcs
       in
         case as of
           Some (pid,c,as) \<Rightarrow> (\<lambda>(a,c'). (pid,c,a,c'))`as
         | None \<Rightarrow> ga_gen gc"
     
     definition "ga_ample sticky_E 
       \<equiv> stutter_extend_en (ga_gample sticky_E)"
 
     lemma ga_gample_subset: "ga_gample sticky_E gc \<subseteq> ga_gen gc"
       unfolding ga_gample_def ga_gen_def
       by (auto 
         simp: comp.astep_impl_def
         split: option.splits if_split_asm 
         dest!: find_min_idx_f_SomeD)
 
     lemma ga_gample_empty_iff: "ga_gample sticky_E gc = {} \<longleftrightarrow> ga_gen gc = {}"  
       unfolding ga_gample_def ga_gen_def
       by (fastforce 
         simp: comp.astep_impl_def
         split: option.splits if_split_asm 
         dest!: find_min_idx_f_SomeD)
 
     lemma ga_ample_None_iff: "None \<in> ga_ample sticky_E gc \<longleftrightarrow> None \<in> ga_en gc"
       by (auto 
         simp: ga_ample_def ga_en_def stutter_extend_en_def ga_gample_empty_iff)
       
     lemma ga_ample_neq_en_eq:
       assumes "ga_ample sticky_E gc \<noteq> ga_en gc"
       shows "ga_ample sticky_E gc = Some`ga_gample sticky_E gc \<and> ga_en gc = Some`ga_gen gc"
       using assms ga_gample_subset
       unfolding ga_ample_def ga_en_def stutter_extend_en_def
       by (auto split: if_split_asm simp: ga_gample_empty_iff)
 
     lemma pid_pac_alt: "pid_pac pid = insert None (Some`{(pid',cac). pid'=pid})" 
       apply (auto simp: pid_pac_def split: option.splits)
       apply (case_tac x)
       apply auto
       done
   end    
 
   context sticky_prog begin
     sublocale ample_prog prog is_vis_var sticky_E "ga_ample sticky_E"
     proof -
       have aux: "Some ` A = Some ` B \<inter> pid_pac pid \<longleftrightarrow> A = {(pid', cac). (pid', cac) \<in> B \<and> pid' = pid}"
         for A B pid
       proof
         assume 1: "Some ` A = Some ` B \<inter> pid_pac pid"
         show "A = {(pid', cac). (pid', cac) \<in> B \<and> pid' = pid}"
           using 1
           apply (auto simp: pid_pac_alt)
           unfolding image_def
           apply auto
           using 1 by blast
       next
         show "Some ` A = Some ` B \<inter> pid_pac pid" if "A = {(pid', cac). (pid', cac) \<in> B \<and> pid' = pid}"
           using that by (auto simp: pid_pac_alt)
       qed
       show "ample_prog prog is_vis_var sticky_E (ga_ample sticky_E)"
         apply unfold_locales
         apply (frule ga_ample_neq_en_eq, clarsimp)
         apply (intro conjI)
         apply (auto 
           simp: ga_gample_def sticky_ga_def
           dest!: find_min_idx_f_SomeD
           split: option.splits if_split_asm) []
         apply (fastforce
           simp: ga_gample_def sticky_ga_def
           dest!: find_min_idx_f_SomeD
           split: option.splits if_split_asm) []
         unfolding aux (* TODO: Clean up! *)
         apply (simp add: inj_image_eq_iff pid_pac_def)
         apply (thin_tac "ga_ample c a = b" for a b c)
         apply (simp add: ga_gample_def split: option.splits prod.splits)
         apply (thin_tac "a \<noteq> ga_gen b" for a b)
         apply (drule find_min_idx_f_SomeD)
         apply clarsimp
         apply (rename_tac gc pid c as)
         apply (rule_tac x=pid in exI)
         apply (auto 
           split: if_split_asm prod.splits 
           simp: ga_gen_def comp.astep_impl_def)
         unfolding is_ample_static_def comp.astep_impl_def
         apply force
         done
     qed
 
   end
 
   text \<open> The following locale expresses a correct ample-reduction on 
     the level of subset and stuttering-equivalences of traces \<close>
 
   locale hl_reduction =
     visible_prog +
     ample: sa "\<lparr> g_V = UNIV, g_E = step, g_V0 = {pid_init_gc}, sa_L = pid_interp_gc \<rparr>"
     for step +
     assumes ample_accept_subset: "ample.accept w \<Longrightarrow> lv.sa.accept w"
     assumes ample_accept_stuttering: "lv.sa.accept w \<Longrightarrow> \<exists>w'. w\<approx>w' \<and> ample.accept w'"
 
   locale hl_ample_reduction =
     visible_prog +
     ample: sa "\<lparr> g_V = UNIV, g_E = rel_of_enex (ample, ga_ex), g_V0 = {pid_init_gc},
       sa_L = pid_interp_gc \<rparr>"
     for ample +
     assumes ample_accept_subset: "ample.accept w \<Longrightarrow> lv.sa.accept w"
     assumes ample_accept_stuttering: "lv.sa.accept w \<Longrightarrow> \<exists>w'. w\<approx>w' \<and> ample.accept w'"
   begin
     sublocale hl_reduction prog is_vis_var "rel_of_enex (ample, ga_ex)"
       apply unfold_locales
       using ample_accept_subset ample_accept_stuttering by auto
   end
 
 
   context sticky_prog
   begin
     sublocale hl_ample: hl_ample_reduction prog is_vis_var "ga_ample sticky_E"
       apply unfold_locales
       unfolding ample_rel_def[symmetric]
       unfolding reduced_automaton_def[symmetric]
       apply simp
       apply simp
       using ample_accept_subset
       apply simp
       apply (erule ample_accept_stuttering)
       apply blast
       done
   end    
 
   text \<open>Next, we implement the selection of a set of sticky edges\<close>
   context visible_prog begin
     definition "cr_ample \<equiv> do {
       sticky_E \<leftarrow> find_fas_init cfgc_G vis_edges;
       RETURN (ga_ample (sticky_E))
     }"
 
     lemma cr_ample_reduction: 
       "cr_ample \<le> SPEC (hl_ample_reduction prog is_vis_var)"
       unfolding cr_ample_def
       apply (refine_vcg order_trans[OF find_fas_init_correct])
       apply unfold_locales[]
       apply simp
     proof clarify  
       fix sticky_E
       assume "is_fas cfgc_G sticky_E" "vis_edges \<subseteq> sticky_E"
       then interpret sticky_prog prog is_vis_var sticky_E
         by unfold_locales
 
       show "hl_ample_reduction prog is_vis_var (ga_ample sticky_E)" by unfold_locales
     qed
   end  
 
   text \<open>We derive an implementation for finding the feedback arcs,
     and an efficient implementation for ga_gample.\<close>
 
   text \<open>We replace finding the sticky edges by an efficient algorithm\<close>
 
   context visible_prog begin
     definition ga_gample_m 
       :: "_ \<Rightarrow> _ \<Rightarrow> pid_global_config \<Rightarrow> global_action set" 
     where
       "ga_gample_m mem sticky_E gc \<equiv> let
         lcs = pid_global_config.processes gc;
         gs = pid_global_config.state gc;
         as = find_min_idx_f (\<lambda>lc.
           let
             c = local_config.command lc;
             ls = local_config.state lc;
             as = set (comp.succ_impl c)
           in
             if (\<forall>(a,_)\<in>as. read_globals a = {} \<and> write_globals a = {}) then
               let 
                 as = {(a,c')\<in>as. la_en' (ls,gs) a}
               in
                 if as={} \<or> (\<exists>(a,c')\<in>as. mem (c,c') sticky_E) then 
                   None 
                 else 
                   Some (c,as)
             else
               None
         ) lcs
       in
         case as of
           Some (pid,c,as) \<Rightarrow> (\<lambda>(a,c'). (pid,c,a,c'))`as
         | None \<Rightarrow> ga_gen gc"
 
     lemma ga_gample_m_refine:
       fixes Rs :: "('si\<times>'s) set"
       shows "(ga_gample_m, ga_gample_m) \<in> (Id\<times>\<^sub>rId \<rightarrow> Rs \<rightarrow> bool_rel) \<rightarrow> Rs \<rightarrow> Id \<rightarrow> \<langle>Id\<rangle>set_rel"
     proof (intro fun_relI, simp)  
       fix m :: "cmdc\<times>cmdc \<Rightarrow> 's \<Rightarrow> bool" and m' :: "cmdc\<times>cmdc \<Rightarrow> 'si \<Rightarrow> bool" 
         and se se' gc
       assume "(m',m)\<in>Id \<rightarrow> Rs \<rightarrow> bool_rel" and "(se',se)\<in>Rs"
       hence "\<And>c c'. (m' (c,c') se', m (c,c') se)\<in>Id" 
         by parametricity simp_all
       hence A: "\<And>c c'. m' (c,c') se' = m (c,c') se" by simp
       show "ga_gample_m m' se' gc = ga_gample_m m se gc"
         unfolding ga_gample_m_def
         by (subst A) (rule refl)
     qed             
 
     lemma ga_gample_eq_gample_m: "ga_gample = ga_gample_m (\<in>)"
       unfolding ga_gample_def[abs_def] ga_gample_m_def[abs_def]
       by auto
 
     lemma stutter_extend_en_refine: 
       "(stutter_extend_en, stutter_extend_en) \<in> (R \<rightarrow> \<langle>Id\<rangle>set_rel) \<rightarrow> R \<rightarrow> \<langle>\<langle>Id\<rangle>option_rel\<rangle>set_rel"
       unfolding stutter_extend_en_def[abs_def]
       apply parametricity
       by auto
 
     lemma is_vis_var_refine: "(is_vis_var, is_vis_var) \<in> Id \<rightarrow> bool_rel" by simp  
 
     lemma vis_edges_refine: "(\<lambda>x. x\<in>vis_edges,vis_edges)\<in>\<langle>Id\<times>\<^sub>rId\<rangle>fun_set_rel"
       by (simp add: fun_set_rel_def br_def)
 
     lemma [autoref_op_pat_def]: 
       "vis_edges \<equiv> Autoref_Tagging.OP vis_edges"  
       "ga_gample_m \<equiv> Autoref_Tagging.OP ga_gample_m"  
       "cfgc_G \<equiv> Autoref_Tagging.OP cfgc_G"
       by simp_all
 
     schematic_goal cr_ample_impl1_aux:
       notes [autoref_rules] = 
         ga_gample_m_refine stutter_extend_en_refine is_vis_var_refine
         cfgc_G_impl_refine
         vis_edges_refine IdI[of prog]
       shows "(RETURN (?c::?'c),cr_ample)\<in>?R"
       unfolding cr_ample_def ga_ample_def ga_gample_eq_gample_m
       using [[autoref_trace_failed_id, autoref_trace_intf_unif]]
       by (autoref_monadic (plain, trace))
     concrete_definition cr_ample_impl1 uses cr_ample_impl1_aux
 
     lemma cr_ample_impl1_reduction: 
       "hl_ample_reduction prog is_vis_var cr_ample_impl1"
     proof -
       note cr_ample_impl1.refine[THEN nres_relD]
       also note cr_ample_reduction
       finally show ?thesis by simp
     qed
 
   end
 
   text \<open>The efficient implementation of @{const visible_prog.ga_gample} uses 
     the @{const collecti_index} function\<close> 
 
   lemma collecti_index_cong:
     assumes C: "\<And>i. i<length l \<Longrightarrow> f i (l!i) = f' i (l'!i)"
     assumes [simp]: "l=l'"
     shows "collecti_index f l = collecti_index f' l'"
   proof -
     {
       fix i0 s0
       assume "\<forall>i<length l. f (i0+i) (l!i) = f' (i0+i) (l!i)"
       hence "collecti_index' i0 s0 f l = collecti_index' i0 s0 f' l"
       proof (induction l arbitrary: i0 s0)
         case (Cons a l)
 
         from Cons.prems[THEN spec, of 0] have 
           [simp]: "f i0 a = f' i0 a" by simp
 
         from Cons.prems have 
           IHP: "\<forall>i<length l. f (Suc i0+i) (l!i) = f' (Suc i0+i) (l!i)"
           by auto
 
         show ?case by (auto split: bool.splits simp: Cons.IH[OF IHP])
       qed simp
     } from this[of 0 "{}"] show ?thesis using assms by simp
   qed  
 
   lemma find_min_idx_f_cong:
     assumes "\<And>x. x\<in>set l \<Longrightarrow> f x = f' x"
     assumes "l=l'"
     shows "find_min_idx_f f l = find_min_idx_f f' l'"
     unfolding assms(2)[symmetric]
     using assms(1)
     apply (induction l)
     apply (auto split: option.split)
     done
 
 
   lemma find_min_idx_impl_collecti: "(
       case find_min_idx_f f l of
         Some (i,r) \<Rightarrow> {i} \<times> s1 i r
       | None \<Rightarrow> {(i,r) | i r. i<length l \<and> r\<in>s2 i (l!i)}  
     )
   = (
     collecti_index (\<lambda>i x. 
       case f x of
         Some r \<Rightarrow> (True, s1 i r)
       | None \<Rightarrow> (False, s2 i x)
     ) l
   )" (is "?l=?r" is "_ = collecti_index ?fc l") 
   proof (cases "\<exists>i<length l. f (l!i) \<noteq> None")
     define i where "i \<equiv> LEAST i. i < length l \<and> f (l ! i) \<noteq> None"
     
     have C_ALT: "(\<exists>i<length l. f (l!i) \<noteq> None) 
       \<longleftrightarrow> (\<exists>i. i < length l \<and> fst (?fc i (l ! i)))"
       by (auto split: option.split)
 
     have i_alt: "i = (LEAST i. i < length l \<and> fst (?fc i (l ! i)))" 
       unfolding i_def 
       apply (fo_rule arg_cong)
       by (auto split: option.split)
 
     {  
       case True
   
       from LeastI_ex[OF True] obtain r where [simp]: "i<length l" "f (l!i) = Some r"
         by (auto simp: i_def)
   
       from True find_min_idx_f_LEAST_eq[of f l] 
         have "find_min_idx_f f l = Some (i, the (f (l ! i)))" 
         by (simp add: i_def)
       hence LEQ: "?l = {i} \<times> s1 i r" by simp
 
       from collecti_index_collect[of ?fc l, folded i_alt] True C_ALT have 
         REQ: "?r = {i} \<times> snd (?fc i (l!i))" 
         by simp
       show "?l=?r" unfolding LEQ unfolding REQ by auto
     }
     {
       case False
       from False find_min_idx_f_LEAST_eq[of f l] 
         have "find_min_idx_f f l = None" by simp
       hence LEQ: "?l = {(i,r) | i r. i<length l \<and> r\<in>s2 i (l!i)}" by simp
 
       from False C_ALT collecti_index_collect[of ?fc l] have
         REQ: "?r = {(i, x) |i x. i < length l \<and> x \<in> snd (?fc i (l ! i))}"
         by auto
 
       show "?l=?r" unfolding LEQ unfolding REQ using False by auto
     }
   qed
 
 
   lemma find_min_idx_impl_collecti_scheme: 
     assumes "\<And>x. s11 x = (case x of (i,r) \<Rightarrow> {i} \<times> iss i r)"
     assumes "s12 = {(i,r) | i r. i<length l \<and> r\<in>isn i (l!i)}"
     assumes "\<And>i. i<length l \<Longrightarrow> f2 i (l!i) = (case f (l!i) of
         Some r \<Rightarrow> (True, iss i r)
       | None \<Rightarrow> (False, isn i (l!i)))"
     shows "(case find_min_idx_f f l of Some x \<Rightarrow> s11 x | None \<Rightarrow> s12)
       = (collecti_index f2 l)"
     apply (simp only: assms(1,2,3) cong: collecti_index_cong)  
     apply (subst find_min_idx_impl_collecti)
     apply simp
     done
 
 
   schematic_goal stutter_extend_en_list_aux: "(?c, stutter_extend_en) 
     \<in> (R \<rightarrow> \<langle>S\<rangle>list_set_rel) \<rightarrow> R \<rightarrow> \<langle>\<langle>S\<rangle>option_rel\<rangle>list_set_rel"
     unfolding stutter_extend_en_def[abs_def]
     apply (autoref)
     done
   concrete_definition stutter_extend_en_list uses stutter_extend_en_list_aux
 
   lemma succ_of_enex_impl_aux: 
     "{s'. \<exists>a\<in>en s. s'=ex a s} = (\<lambda>a. ex a s)`en s" by auto
 
   schematic_goal succ_of_enex_list_aux: "(?c, succ_of_enex) \<in> 
     (Id \<rightarrow> \<langle>Id\<rangle>list_set_rel) \<times>\<^sub>r (Id \<rightarrow> Id \<rightarrow> Id) \<rightarrow> Id \<rightarrow> \<langle>Id\<rangle>list_set_rel"
     unfolding succ_of_enex_def[abs_def]
     unfolding succ_of_enex_impl_aux
     by (autoref (trace, keep_goal))
   concrete_definition succ_of_enex_list uses succ_of_enex_list_aux
 
   schematic_goal pred_of_enex_list_aux: "(?c, pred_of_enex) \<in> 
     (Id \<rightarrow> \<langle>Id\<rangle>list_set_rel) \<times>\<^sub>r (Id \<rightarrow> Id \<rightarrow> Id) \<rightarrow> Id \<rightarrow> Id \<rightarrow> bool_rel"
     unfolding pred_of_enex_def[abs_def]
     by (autoref (trace, keep_goal))
   concrete_definition pred_of_enex_list uses pred_of_enex_list_aux
 
   (* TODO: can this be defined using autoref? *)
   definition "rel_of_enex_list enex \<equiv> rel_of_pred (pred_of_enex_list enex)"
   lemma rel_of_enex_list_refine: "(rel_of_enex_list, rel_of_enex) \<in> 
     (Id \<rightarrow> \<langle>Id\<rangle>list_set_rel) \<times>\<^sub>r (Id \<rightarrow> Id \<rightarrow> Id) \<rightarrow> \<langle>Id \<times>\<^sub>r Id\<rangle> set_rel"
   proof -
     have 1: "rel_of_enex_list = rel_of_pred \<circ> pred_of_enex_list" using rel_of_enex_list_def by force
     have 2: "rel_of_enex = rel_of_pred \<circ> pred_of_enex" by auto
     have 3: "(rel_of_pred, rel_of_pred) \<in> (Id \<rightarrow> Id \<rightarrow> bool_rel) \<rightarrow> \<langle>Id \<times>\<^sub>r Id\<rangle>set_rel" by auto
     show ?thesis unfolding 1 2 by (parametricity add: 3 pred_of_enex_list.refine)
   qed
 
   context visible_prog begin
     definition "ga_gample_mi2 mem sticky_E (gc::pid_global_config) = (
       let 
         lcs = pid_global_config.processes gc;
         gs = pid_global_config.state gc
       in
         collecti_index (\<lambda>_ lc. let
             c = local_config.command lc;
             ls = local_config.state lc;
             as = set (comp.succ_impl c);
             s={(a,c')\<in>as. la_en' (ls,gs) a};
             ample = 
               s\<noteq>{} 
             \<and> (\<forall>(a,_)\<in>as. read_globals a = {} \<and> write_globals a = {}) 
             \<and> (\<forall>(a,c')\<in>s. \<not> mem (c,c') sticky_E)
           in
             (ample,{c}\<times>s)
         ) lcs
     )"
 
     lemma ga_gample_mi2_impl: 
       "ga_gample_m mem sticky_E gc = ga_gample_mi2 mem sticky_E gc"
       unfolding ga_gample_m_def ga_gample_mi2_def
       apply simp
       apply (rule find_min_idx_impl_collecti_scheme[where 
           iss="\<lambda>pid (c,S). (\<lambda>(a,c'). (c,a,c'))`S" and
           isn="\<lambda>pid lc. {(c,a,c'). cfgc c a c' 
             \<and> c = cmd_of_pid gc pid 
             \<and> la_en' (local_config.state lc, pid_global_config.state gc) a}"]
       )
       apply auto []
       unfolding ga_gen_def
       apply auto []
       apply (auto simp: comp.astep_impl_def)
       done
 
     definition "cr_ample_impl2 \<equiv>
       let sticky = find_fas_init_code (=) bounded_hashcode_nat
          (def_hashmap_size TYPE(nat)) cfgc_G_impl (\<lambda>x. x \<in> vis_edges)
       in stutter_extend_en (ga_gample_mi2 (\<lambda>x f. f x) sticky)"
 
     definition "ample_step_impl2 \<equiv> rel_of_enex (cr_ample_impl2,ga_ex)"
 
     lemma cr_ample_impl2_reduction: 
       "hl_reduction prog is_vis_var ample_step_impl2"
     proof -
       from cr_ample_impl1_reduction 
       interpret hl_ample_reduction prog is_vis_var cr_ample_impl1 .
       
       have 1: "ample_step_impl2 = rel_of_enex (cr_ample_impl1, ga_ex)"
         unfolding ample_step_impl2_def cr_ample_impl1_def cr_ample_impl2_def
         unfolding ga_gample_mi2_impl[abs_def]
         by simp
 
       show ?thesis
         apply unfold_locales
         unfolding 1
         apply simp
         apply simp
         apply (blast intro: ample_accept_subset ample_accept_stuttering)+
         done
     qed
   end
         
 text \<open>Implementing the State\<close>
 type_synonym valuation_impl = "(ident,uint32) mapping"
 
 definition "vi_\<alpha> \<equiv> map_option Rep_uint32 \<circ>\<circ> Mapping.rep"
 abbreviation "vi_rel \<equiv> br vi_\<alpha> (\<lambda>_. True)"
 
 abbreviation "val_rel \<equiv> br Rep_uint32 (\<lambda>_. True)"
 
 lemma vi_rel_rew: 
   "(x = vi_\<alpha> y) \<longleftrightarrow> (y,x)\<in>vi_rel"
   "(vi_\<alpha> y = x) \<longleftrightarrow> (y,x)\<in>vi_rel"
   by (auto simp: br_def)
 
 export_code Mapping.lookup Mapping.update Mapping.empty checking SML
 
 lift_definition vi_empty :: "valuation_impl" 
   is "Map.empty::valuation" .
 
 lemma [code]: "vi_empty = Mapping.empty" by transfer simp
 lemma vi_empty_correct: "vi_\<alpha> vi_empty = Map.empty"
   unfolding vi_\<alpha>_def
   by transfer auto
 
 lift_definition vi_lookup :: "valuation_impl \<Rightarrow> ident \<rightharpoonup> uint32" 
   is "\<lambda>vi::valuation. \<lambda>x. vi x" .
 lemma [code]: "vi_lookup = Mapping.lookup"
   apply (intro ext)
   unfolding vi_lookup_def Mapping.lookup_def map_fun_def[abs_def] o_def
     id_apply option.map_comp Rep_uint32_inverse option.map_ident
   by simp
 
 lemma vi_lookup_correct: "vi_lookup v x = map_option Abs_uint32 (vi_\<alpha> v x)"
   unfolding vi_\<alpha>_def
   apply transfer
   apply (simp add: option.map_comp o_def option.map_ident)
   done
 
 lift_definition vi_update :: "ident \<Rightarrow> uint32 \<Rightarrow> valuation_impl \<Rightarrow> valuation_impl" 
   is "\<lambda>x v. \<lambda>vi::valuation. vi(x\<mapsto>v)" .
 lemma [code]: "vi_update = Mapping.update"
   by transfer simp
 
 lemma vi_update_correct: "vi_\<alpha> (vi_update k v m) = vi_\<alpha> m (k\<mapsto>Rep_uint32 v)"
   unfolding vi_\<alpha>_def
   by transfer simp
 
 export_code vi_lookup vi_update vi_empty checking SML 
 
 
 record local_state_impl = 
   variables :: valuation_impl
 
 record global_state_impl = 
   variables :: valuation_impl
 
 type_synonym focused_state_impl = "local_state_impl \<times> global_state_impl"
 
 type_synonym local_config_impl 
   = "(cmdc,local_state_impl) Gen_Scheduler.local_config"
 type_synonym pid_global_config_impl 
   = "(cmdc,local_state_impl,global_state_impl) Pid_Scheduler.pid_global_config"
 
 definition "local_state_rel \<equiv> {
   (\<lparr> local_state_impl.variables = vi \<rparr>, \<lparr> local_state.variables = v  \<rparr>) | vi v.
     v = vi_\<alpha> vi 
   }"
 
 definition "global_state_rel \<equiv> {
   (\<lparr> global_state_impl.variables = vi \<rparr>, \<lparr> global_state.variables = v  \<rparr>) | vi v.
     v = vi_\<alpha> vi 
   }"
 
 abbreviation "focused_state_rel \<equiv> local_state_rel \<times>\<^sub>r global_state_rel"
 
 definition "local_config_rel \<equiv> {
   (\<lparr> local_config.command = ci, local_config.state=lsi \<rparr>, 
    \<lparr> local_config.command = c, local_config.state=ls  \<rparr>) | ci c lsi ls.
     (ci::cmdc,c)\<in>Id \<and> (lsi,ls)\<in>local_state_rel
   }"
 
 definition "global_config_rel \<equiv> {
   (\<lparr> pid_global_config.processes = psi, pid_global_config.state = gsi \<rparr>,
    \<lparr> pid_global_config.processes = ps, pid_global_config.state = gs \<rparr>) | psi ps gsi gs.
    (psi,ps)\<in>\<langle>local_config_rel\<rangle>list_rel \<and> (gsi,gs)\<in>global_state_rel
 }"
 
 definition "init_valuation_impl vd \<equiv> fold (\<lambda>x v. vi_update x 0 v) vd (vi_empty)"
 
 lemma init_valuation_impl: 
   "(init_valuation_impl, init_valuation) \<in> \<langle>Id\<rangle>list_rel \<rightarrow> vi_rel"
 proof -
   {
     fix vd m
     have "m ++ init_valuation vd = fold (\<lambda>x v. v(x\<mapsto>0)) vd m"
       apply (rule sym)
       apply (induction vd arbitrary: m)
       unfolding init_valuation_def[abs_def]
       apply (auto intro!: ext simp: Map.map_add_def)
       done
   } note aux=this
   have E1: "\<And>vd. init_valuation vd = fold (\<lambda>x v. v(x\<mapsto>0)) vd Map.empty"
     by (subst aux[symmetric]) simp
     
   have E2: "\<And>vdi vd. (vdi,vd)\<in>\<langle>Id\<rangle>list_rel 
     \<Longrightarrow> (init_valuation_impl vdi, fold (\<lambda>x v. v(x\<mapsto>0)) vd Map.empty) \<in> vi_rel"
     unfolding init_valuation_impl_def
     apply parametricity
     apply (auto simp: vi_update_correct vi_empty_correct br_def zero_uint32.rep_eq)
     done
 
   show ?thesis
     apply (intro fun_relI)
     apply (subst E1)
     apply (rule E2)
     by auto
 qed
 
 context cprog begin
 
   definition init_pc_impl :: "proc_decl \<Rightarrow> local_config_impl" where
     "init_pc_impl pd \<equiv> \<lparr>
       local_config.command = comp.\<gamma> (proc_decl.body pd),
       local_config.state = \<lparr>
         local_state_impl.variables = init_valuation_impl (proc_decl.local_vars pd)
       \<rparr>
     \<rparr>"
 
   lemma init_pc_impl: "(init_pc_impl, init_pc) \<in> Id \<rightarrow> local_config_rel"
     apply (rule fun_relI)
     unfolding init_pc_impl_def init_pc_def local_config_rel_def local_state_rel_def
     apply (simp del: pair_in_Id_conv, intro conjI)
     apply simp
     apply (simp only: vi_rel_rew)
     apply (parametricity add: init_valuation_impl)
     apply simp
     done
   
   definition pid_init_gc_impl :: "pid_global_config_impl" where
     "pid_init_gc_impl \<equiv> \<lparr>
       pid_global_config.processes = (map init_pc_impl (program.processes prog)),
       pid_global_config.state = \<lparr>
         global_state_impl.variables = init_valuation_impl (program.global_vars prog)
       \<rparr>
     \<rparr>"
   
   lemma pid_init_gc_impl: "(pid_init_gc_impl, pid_init_gc) \<in> global_config_rel"
     unfolding pid_init_gc_impl_def pid_init_gc_def global_config_rel_def global_state_rel_def
     apply (simp del: pair_in_Id_conv, intro conjI)
     apply (parametricity add: init_pc_impl)
     apply simp
     apply (simp only: vi_rel_rew)
     apply (parametricity add: init_valuation_impl)
     apply simp
     done  
 
 end
   
 lift_definition val_of_bool_impl :: "bool \<Rightarrow> uint32" is val_of_bool .
 lemma [code]: "val_of_bool_impl b = (if b then 1 else 0)"
   by transfer auto
 
 lift_definition bool_of_val_impl :: "uint32 \<Rightarrow> bool" is bool_of_val .
 lemma [code]: "bool_of_val_impl v = (v\<noteq>0)"
   by transfer (auto simp: bool_of_val_def)
 
 definition "set_of_rel R \<equiv> {(a,b) . R b a}"
 definition "rel_of_set S \<equiv> \<lambda>b a. (a,b)\<in>S"
 
 lemma [simp]: 
   "(a,b)\<in>set_of_rel R \<longleftrightarrow> R b a"
   "rel_of_set S b a \<longleftrightarrow> (a,b)\<in>S"
   unfolding rel_of_set_def set_of_rel_def
   by auto
 
 lemma [simp]:
   "set_of_rel (rel_of_set S) = S"
   "rel_of_set (set_of_rel R) = R"
   unfolding rel_of_set_def set_of_rel_def
   by auto
 
 lemma rel_fun_2set: "rel_fun A B = rel_of_set (set_of_rel A \<rightarrow> set_of_rel B)"
   unfolding rel_fun_def fun_rel_def
   unfolding rel_of_set_def set_of_rel_def
   by (auto)
 
 lemma [simp]: 
   "set_of_rel cr_uint32 = val_rel"
   "set_of_rel (=) = Id"
   by (auto simp: br_def cr_uint32_def)
 
 lemma bool_of_val_impl: "(bool_of_val_impl, bool_of_val) \<in> val_rel \<rightarrow> bool_rel"
   using bool_of_val_impl.transfer
   by (simp add: rel_fun_2set)
   
 
-
-lemma smod_by_div_abs: "a smod b = a - a sdiv b * b"
+lemma smod_by_div_abs: "a smod b = a - a sdiv b * b" for a b :: \<open>'a::len word\<close>
   by (subst (2) sdiv_smod_id [of a b, symmetric]) simp
 
 lift_definition sdiv_impl :: "uint32 \<Rightarrow> uint32 \<Rightarrow> uint32" is "(sdiv)" .
 lift_definition smod_impl :: "uint32 \<Rightarrow> uint32 \<Rightarrow> uint32" is "(smod)" .
 
 (* TODO: Is there a more efficient way? *)
 lemma [code]: "sdiv_impl x y = Abs_uint32' (Rep_uint32' x sdiv Rep_uint32' y)"
   apply transfer
   by simp
 
 lemma [code]: "smod_impl a b = a - sdiv_impl a b * b"
   by transfer (simp add: smod_by_div_abs)
   
 
 primrec eval_bin_op_impl_aux :: "bin_op \<Rightarrow> uint32 \<Rightarrow> uint32 \<Rightarrow> uint32" where
   "eval_bin_op_impl_aux bo_plus v1 v2 = v1+v2"
 | "eval_bin_op_impl_aux bo_minus v1 v2 = v1-v2"
 | "eval_bin_op_impl_aux bo_mul v1 v2 = v1*v2"
 | "eval_bin_op_impl_aux bo_div v1 v2 = sdiv_impl v1 v2"
 | "eval_bin_op_impl_aux bo_mod v1 v2 = smod_impl v1 v2"
 | "eval_bin_op_impl_aux bo_less v1 v2 = val_of_bool_impl (v1 < v2)"
 | "eval_bin_op_impl_aux bo_less_eq v1 v2 = val_of_bool_impl (v1 \<le> v2)"
 | "eval_bin_op_impl_aux bo_eq v1 v2 = val_of_bool_impl (v1 = v2)"
 | "eval_bin_op_impl_aux bo_and v1 v2 = v1 AND v2"
 | "eval_bin_op_impl_aux bo_or v1 v2 = v1 OR v2"
 | "eval_bin_op_impl_aux bo_xor v1 v2 = v1 XOR v2"
 
 lift_definition eval_bin_op_impl :: "bin_op \<Rightarrow> uint32 \<Rightarrow> uint32 \<Rightarrow> uint32"
   is eval_bin_op .
 print_theorems
 
 lemma [code]: "eval_bin_op_impl bop v1 v2 = eval_bin_op_impl_aux bop v1 v2"
   apply (cases bop)
   apply simp_all
   apply (transfer, simp)+
   done  
 
 
 
 primrec eval_un_op_impl_aux :: "un_op \<Rightarrow> uint32 \<Rightarrow> uint32" where
   "eval_un_op_impl_aux uo_minus v = -v"
 | "eval_un_op_impl_aux uo_not v = NOT v"
 
 lift_definition eval_un_op_impl :: "un_op \<Rightarrow> uint32 \<Rightarrow> uint32"
   is eval_un_op .
 
 lemma [code]: "eval_un_op_impl uop v = eval_un_op_impl_aux uop v"
   apply (cases uop)
   apply simp_all
   apply (transfer, simp)+
   done  
 
 
 
 
 fun eval_exp_impl :: "exp \<Rightarrow> focused_state_impl \<rightharpoonup> uint32" where
   "eval_exp_impl (e_var x) (ls,gs) = do {
     let lv = local_state_impl.variables ls; 
     let gv = global_state_impl.variables gs;
     case vi_lookup lv x of
       Some v \<Rightarrow> Some v
     | None \<Rightarrow> (case vi_lookup gv x of
         Some v \<Rightarrow> Some v
       | None \<Rightarrow> None)
   }"
 | "eval_exp_impl (e_localvar x) (ls,gs) = vi_lookup (local_state_impl.variables ls) x"
 | "eval_exp_impl (e_globalvar x) (ls,gs) = vi_lookup (global_state_impl.variables gs) x"
 | "eval_exp_impl (e_const n) fs = do {
     assert_option (n\<ge>min_signed \<and> n\<le>max_signed);
     Some (uint32_of_int n)
   }"
 | "eval_exp_impl (e_bin bop e1 e2) fs = do {
     v1\<leftarrow>eval_exp_impl e1 fs;
     v2\<leftarrow>eval_exp_impl e2 fs;
     Some (eval_bin_op_impl bop v1 v2)
     }"
 | "eval_exp_impl (e_un uop e) fs = do {
     v\<leftarrow>eval_exp_impl e fs;
     Some (eval_un_op_impl uop v)
     }"
 
 (* TODO: Move *)
 lemma map_option_bind: "map_option f (m\<bind>g) = m \<bind> (map_option f o g)"
   by (auto split: Option.bind_split)
 
 lemma val_option_rel_as_eq: "(a,b)\<in>\<langle>val_rel\<rangle>option_rel \<longleftrightarrow> map_option Rep_uint32 a = b"
   unfolding br_def
   apply (cases a)
   apply (cases b, simp_all)
   apply (cases b, auto)
   done
 
 lemma eval_exp_impl: "(eval_exp_impl, eval_exp) \<in> Id \<rightarrow> focused_state_rel \<rightarrow> \<langle>val_rel\<rangle>option_rel"
 proof -
   {
     fix e ls gs lsi gsi
     assume "(lsi,ls)\<in>local_state_rel" "(gsi,gs)\<in>global_state_rel"
     hence "map_option Rep_uint32 (eval_exp_impl e (lsi,gsi)) = eval_exp e (ls,gs)"
       apply (induction e)
       apply (auto 
         simp: local_state_rel_def global_state_rel_def br_def
         simp: vi_lookup_correct vi_update_correct
         simp: Abs_uint32_inverse[simplified] uint32_of_int.rep_eq signed_of_int_def
         simp: option.map_comp option.map_ident o_def map_option_bind
         simp: eval_bin_op_impl.rep_eq eval_un_op_impl.rep_eq
         split: option.splits)
       apply (drule sym)
       apply (drule sym)
       apply (simp split: Option.bind_split)
 
       apply (drule sym)
       apply (simp split: Option.bind_split)
       done
   } thus ?thesis
     by (auto simp: val_option_rel_as_eq)
 qed
 
 text \<open>Enabledness and effects of actions\<close>
 primrec la_en_impl :: "focused_state_impl \<Rightarrow> action \<rightharpoonup> bool" where
   "la_en_impl fs (AAssign e _ _) = do {
     v \<leftarrow> eval_exp_impl e fs;
     Some (bool_of_val_impl v)}"
 | "la_en_impl fs (AAssign_local e _ _) = do {
     v \<leftarrow> eval_exp_impl e fs;
     Some (bool_of_val_impl v)}"
 | "la_en_impl fs (AAssign_global e _ _) = do {
     v \<leftarrow> eval_exp_impl e fs;
     Some (bool_of_val_impl v)}"
 | "la_en_impl fs (ATest e) = do {
     v \<leftarrow> eval_exp_impl e fs;
     Some (bool_of_val_impl v)}"
 | "la_en_impl _ (ASkip) = Some True"
 
 lemma param_rec_action[param]: "(rec_action, rec_action) \<in> (Id \<rightarrow> Id \<rightarrow> Id \<rightarrow> A)
     \<rightarrow> (Id \<rightarrow> Id \<rightarrow> Id \<rightarrow> A)
        \<rightarrow> (Id \<rightarrow> Id \<rightarrow> Id \<rightarrow> A) \<rightarrow> (Id \<rightarrow> A) \<rightarrow> A \<rightarrow> Id \<rightarrow> A"
   apply (intro fun_relI)
   subgoal for fi1 f1 fi2 f2 fi3 f3 fi4 f4 fi5 f5 ai a
     apply simp
     apply (induction a)
     apply simp_all
     apply (parametricity, simp_all?)+
     done
   done 
 
 (* TODO: Move *)
 lemma param_option_bind[param]:
   "(Option.bind, Option.bind) \<in> \<langle>A\<rangle>option_rel \<rightarrow> (A \<rightarrow> \<langle>B\<rangle>option_rel) \<rightarrow> \<langle>B\<rangle>option_rel"
   unfolding Option.bind_def by parametricity
 
 lemma la_en_impl: "(la_en_impl,la_en) \<in> focused_state_rel \<rightarrow> Id \<rightarrow> \<langle>Id\<rangle>option_rel"
   unfolding la_en_impl_def la_en_def
   by (parametricity add: eval_exp_impl bool_of_val_impl)
 
 definition "la_en'_impl fs a \<equiv> case la_en_impl fs a of Some b \<Rightarrow> b | None \<Rightarrow> False"
   
 lemma la_en'_impl: "(la_en'_impl,la_en') \<in> focused_state_rel \<rightarrow> Id \<rightarrow> bool_rel"
   unfolding la_en'_impl_def[abs_def] la_en'_def[abs_def]
   by (parametricity add: la_en_impl)    
 
 abbreviation "exists_var_impl v x \<equiv> vi_lookup v x \<noteq> None"
 
 fun la_ex_impl :: "focused_state_impl \<Rightarrow> action \<rightharpoonup> focused_state_impl" where
   "la_ex_impl (ls,gs) (AAssign ge x e) = do {
     v \<leftarrow> eval_exp_impl ge (ls,gs);
     assert_option (bool_of_val_impl v); 
     v \<leftarrow> eval_exp_impl e (ls,gs);
     if exists_var_impl (local_state_impl.variables ls) x then do {
       let ls = local_state_impl.variables_update (vi_update x v) ls;
       Some (ls,gs)
     } else do {
       assert_option (exists_var_impl (global_state_impl.variables gs) x);
       let gs = global_state_impl.variables_update (vi_update x v) gs;
       Some (ls,gs)
     }
   }"
 | "la_ex_impl (ls,gs) (AAssign_local ge x e) = do {
     v \<leftarrow> eval_exp_impl ge (ls,gs);
     assert_option (bool_of_val_impl v); 
     v \<leftarrow> eval_exp_impl e (ls,gs);
     assert_option (exists_var_impl (local_state_impl.variables ls) x);
     let ls = local_state_impl.variables_update (vi_update x v) ls;
     Some (ls,gs)
   }"
 | "la_ex_impl (ls,gs) (AAssign_global ge x e) = do {
     v \<leftarrow> eval_exp_impl ge (ls,gs);
     assert_option (bool_of_val_impl v); 
     v \<leftarrow> eval_exp_impl e (ls,gs);
     assert_option (exists_var_impl (global_state_impl.variables gs) x);
     let gs = global_state_impl.variables_update (vi_update x v) gs;
     Some (ls,gs)
   }"
 | "la_ex_impl fs (ATest e) = do {
     v \<leftarrow> eval_exp_impl e fs;
     assert_option (bool_of_val_impl v); 
     Some fs
   }"
 | "la_ex_impl fs ASkip = Some fs"
 
 (* TODO: Move *)
 lemma param_assert_option[param]:
   "(assert_option, assert_option) \<in> bool_rel \<rightarrow> \<langle>unit_rel\<rangle>option_rel"
   unfolding assert_option_def by parametricity
 
 
 lemma la_ex_impl: "(la_ex_impl, la_ex) 
   \<in> focused_state_rel \<rightarrow> Id \<rightarrow> \<langle>focused_state_rel\<rangle>option_rel"
 proof (intro fun_relI)
   fix fsi fs and ai a :: action
   assume "(fsi,fs)\<in>focused_state_rel" "(ai,a)\<in>Id"
   thus "(la_ex_impl fsi ai, la_ex fs a)\<in>\<langle>focused_state_rel\<rangle>option_rel"
     apply (cases fs, cases fsi, clarsimp)
     apply (cases a)
     apply simp_all
     apply (parametricity add: eval_exp_impl bool_of_val_impl)
     apply (auto 
       simp: local_state_rel_def global_state_rel_def
       simp: vi_lookup_correct vi_update_correct 
       simp: br_def 
       intro: domI) [7]
     apply (parametricity add: eval_exp_impl bool_of_val_impl)
     apply (auto 
       simp: local_state_rel_def global_state_rel_def
       simp: vi_lookup_correct vi_update_correct 
       br_def intro: domI) [9]
     apply (parametricity add: eval_exp_impl bool_of_val_impl)
     apply (auto 
       simp: local_state_rel_def global_state_rel_def
       simp: vi_lookup_correct vi_update_correct 
       br_def intro: domI) [4]
     apply (parametricity add: eval_exp_impl bool_of_val_impl)
     apply simp
     done
 qed    
 
 definition "la_ex'_impl fs a \<equiv> case la_ex_impl fs a of Some fs' \<Rightarrow> fs' | None \<Rightarrow> fs"
 lemma la_ex'_impl: "(la_ex'_impl,la_ex') \<in> focused_state_rel \<rightarrow> Id \<rightarrow> focused_state_rel"
   unfolding la_ex'_impl_def[abs_def] la_ex'_def[abs_def]
   by (parametricity add: la_ex_impl)
 
 lemma param_collecti_index: "(collecti_index, collecti_index) \<in> 
     (nat_rel \<rightarrow> B \<rightarrow> bool_rel \<times>\<^sub>r \<langle>Id\<rangle>set_rel) \<rightarrow> \<langle>B\<rangle>list_rel \<rightarrow> \<langle>nat_rel \<times>\<^sub>r Id\<rangle>set_rel"
   unfolding collecti_index'_def
   apply parametricity  
   apply auto
   done
 
 export_code la_ex_impl la_en_impl checking SML
 
 context visible_prog
 begin
 
   definition "ga_gample_mi3 mem sticky_E (gc::pid_global_config_impl) = (
     let 
       lcs = pid_global_config.processes gc;
       gs = pid_global_config.state gc
     in
       collecti_index (\<lambda>_ lc. let
           c = local_config.command lc;
           ls = local_config.state lc;
           as = set (comp.succ_impl c);
           s={(a,c')\<in>as. la_en'_impl (ls,gs) a};
           ample = 
             s\<noteq>{} 
           \<and> (\<forall>(a,_)\<in>as. read_globals a = {} \<and> write_globals a = {}) 
           \<and> (\<forall>(a,c')\<in>s. \<not> mem (c,c') sticky_E)
         in
           (ample,{c}\<times>s)
       ) lcs
   )"
 
   lemma ga_gample_mi3_refine: 
     "(ga_gample_mi3, ga_gample_mi2)\<in> 
       Id \<rightarrow> Id \<rightarrow> global_config_rel \<rightarrow> \<langle>nat_rel \<times>\<^sub>r Id\<rangle>set_rel"
   proof -
     have [param]: "(comp.succ_impl,comp.succ_impl)\<in>Id\<rightarrow>\<langle>Id\<times>\<^sub>rId\<rangle>list_rel"
       by simp
 
     from la_en'_impl have aux1: "\<And>fsi fs a. (fsi,fs)\<in>focused_state_rel \<Longrightarrow>
       la_en'_impl fsi a = la_en' fs a"
       apply (rule_tac IdD)
       apply parametricity
       by auto
 
     show ?thesis
       using [[goals_limit=1]]
       apply (intro fun_relI)
       unfolding ga_gample_mi3_def ga_gample_mi2_def
       apply (parametricity add: param_collecti_index la_en'_impl)
       apply (auto simp add: global_config_rel_def local_config_rel_def) []
       apply (auto simp add: global_config_rel_def local_config_rel_def) []
       apply (auto simp add: global_config_rel_def local_config_rel_def) []
       apply (auto simp add: global_config_rel_def local_config_rel_def) []
       apply simp
       using aux1
       apply (auto simp add: global_config_rel_def local_config_rel_def) []
       apply simp_all
       done
 
   qed    
 
   definition (in cprog) "is_vis_edge is_vis_var \<equiv> \<lambda>(c,c'). 
     \<exists>(a,cc')\<in>set (comp.succ_impl c). c'=cc' \<and> (\<exists>v\<in>write_globals a. is_vis_var v)"
 
   lemma is_vis_edge_correct: "is_vis_edge is_vis_var = (\<lambda>x. x\<in>vis_edges)"
     unfolding is_vis_edge_def vis_edges_def
     by (auto intro!: ext simp: comp.astep_impl_def)
 
 
   definition "cr_ample_impl3 \<equiv>
     let sticky = find_fas_init_code (=) bounded_hashcode_nat
          (def_hashmap_size TYPE(nat)) cfgc_G_impl (\<lambda>x. x \<in> vis_edges)
     in stutter_extend_en (ga_gample_mi3 (\<lambda>x f. f x) sticky)"
 
     
   lemma cr_ample_impl3_refine: "(cr_ample_impl3, cr_ample_impl2) 
     \<in> global_config_rel \<rightarrow> \<langle>\<langle>nat_rel\<times>\<^sub>rId\<rangle>option_rel\<rangle>set_rel"
   proof -
     have [param]: "\<And>R S. S=Id \<Longrightarrow> 
       (stutter_extend_en, stutter_extend_en)
         \<in> (R \<rightarrow> \<langle>S\<rangle>set_rel) \<rightarrow> R \<rightarrow> \<langle>\<langle>S\<rangle>option_rel\<rangle>set_rel"
       apply (simp only: )
       by (rule stutter_extend_en_refine)
     
     show ?thesis  
       unfolding cr_ample_impl3_def cr_ample_impl2_def is_vis_edge_correct
       apply (parametricity add: stutter_extend_en_refine ga_gample_mi3_refine)
       apply (rule IdI)
       by auto
   qed      
       
 (* TODO: The current Pid_Scheduler-locale is focused on refinement.
   We cannot use it to get an instantiation of ga_gex_impl.*)
 
   definition (in -) ga_gex_impl 
     :: "global_action \<Rightarrow> pid_global_config_impl \<Rightarrow> pid_global_config_impl"
   where
     "ga_gex_impl ga gc \<equiv> let 
       (pid,c,a,c') = ga;
       fs = fs_of_pid gc pid;
       (ls',gs') = la_ex'_impl fs a;
       gc' = \<lparr> 
           pid_global_config.processes = (pid_global_config.processes gc)
             [pid := 
               \<lparr> local_config.command = c', local_config.state = ls'\<rparr>
             ],
           pid_global_config.state = gs'\<rparr>
     in
       gc'"
 
 
   lemma lc_of_pid_refine:
     assumes V: "pid_valid gc pid"    
     assumes [param]: "(pidi,pid)\<in>nat_rel"
     assumes GCI: "(gci,gc)\<in>global_config_rel"
     shows "(lc_of_pid gci pidi, lc_of_pid gc pid)\<in>local_config_rel"
     apply parametricity
     apply fact
     using GCI by (auto simp: global_config_rel_def)
     
   lemma ls_of_pid_refine:
     assumes "pid_valid gc pid"    
     assumes "(pidi,pid)\<in>nat_rel"
     assumes "(gci,gc)\<in>global_config_rel"
     shows "(ls_of_pid gci pidi, ls_of_pid gc pid)\<in>local_state_rel"
     using lc_of_pid_refine[OF assms] unfolding local_config_rel_def by auto
 
 
   lemma ga_gex_impl:
     assumes V: "pid_valid gc pid"    
     assumes [param]: "(pidi,pid)\<in>Id" "(ci,c)\<in>Id" 
       "(ai,a)\<in>Id" and CI'I: "(ci',c')\<in>Id" and GCI[param]: "(gci,gc)\<in>global_config_rel"
     shows "(ga_gex_impl (pidi,ci,ai,ci') gci, ga_gex (pid,c,a,c') gc) \<in> global_config_rel"
     unfolding ga_gex_impl_def[abs_def] ga_gex_def[abs_def]
     apply simp
     apply (parametricity add: la_ex'_impl ls_of_pid_refine[OF V])
     using GCI CI'I
     apply (auto simp: global_config_rel_def local_config_rel_def) []
     apply parametricity
     apply auto []
     using GCI
     apply (auto simp: global_config_rel_def) []
     done
 
   definition (in -) "ga_ex_impl \<equiv> stutter_extend_ex ga_gex_impl"
 
   fun ga_valid where
     "ga_valid gc None = True"
   | "ga_valid gc (Some (pid,c,a,c')) = pid_valid gc pid"  
 
 
   lemma ga_ex_impl:
     assumes V: "ga_valid gc ga"    
     assumes P: "(gai,ga)\<in>Id" "(gci,gc)\<in>global_config_rel"
     shows "(ga_ex_impl gai gci, ga_ex ga gc) \<in> global_config_rel"
     using assms
     apply (cases "(gc,ga)" rule: ga_valid.cases)
     using P
     apply (simp add: ga_ex_impl_def)
 
     apply (simp add: ga_ex_impl_def ga_ex_def)
     apply (parametricity add: ga_gex_impl)
     by auto
 
   definition "ample_step_impl3 \<equiv> rel_of_enex (cr_ample_impl3,ga_ex_impl)"
 
   definition (in -) pid_interp_gc_impl 
     :: "(ident \<Rightarrow> bool) \<Rightarrow> pid_global_config_impl \<Rightarrow> exp set"
   where
     "pid_interp_gc_impl is_vis_var gci \<equiv> sm_props (
     vi_\<alpha> (global_state_impl.variables (pid_global_config.state gci)) |` Collect is_vis_var
   )"
 
   lemma pid_interp_gc_impl: 
     "(pid_interp_gc_impl is_vis_var, pid_interp_gc) \<in> global_config_rel \<rightarrow> Id"
     apply rule
     unfolding pid_interp_gc_impl_def pid_interp_gc_def
     apply (auto simp: global_config_rel_def global_state_rel_def 
       interp_gs_def sm_props_def br_def)
     done
 
   lemma cr_ample_impl3_sim_aux:
     assumes GCI: "(gci, gc) \<in> global_config_rel"
     assumes GA: "ga \<in> cr_ample_impl3 gci"
     shows "\<exists>gc'. ga\<in>cr_ample_impl2 gc 
       \<and> gc'=ga_ex ga gc 
       \<and> (ga_ex_impl ga gci, gc')\<in>global_config_rel"
   proof (clarsimp, safe)
     show G1: "ga\<in>cr_ample_impl2 gc"
       using cr_ample_impl3_refine[param_fo, OF GCI] GA by auto
 
     { (* TODO: We are re-proving the validity of the action, due
         to the lack of a clean refinement argumentation *)
       fix mem sticky_E gc pid c
       assume "(pid,c)\<in>ga_gample_m mem sticky_E gc"
       hence "pid_valid gc pid"
         unfolding ga_gample_m_def
         apply (auto split: option.splits)
         apply (auto simp: ga_gen_def) []
         apply (auto dest: find_min_idx_f_SomeD)
         done
     } note aux=this 
     from G1 have "ga_valid gc ga" 
       unfolding cr_ample_impl2_def stutter_extend_en_def
       apply (simp split: if_split_asm)
       unfolding ga_gample_mi2_impl[symmetric]
       apply (auto dest: aux)
       done
     thus "(ga_ex_impl ga gci, ga_ex ga gc)\<in>global_config_rel"
       by (parametricity add: ga_ex_impl GCI IdI[of ga])
   qed    
 
   lemma cr_ample_impl3_sim_aux2:
     assumes GCI: "(gci, gc) \<in> global_config_rel"
     assumes GA: "ga \<in> cr_ample_impl2 gc"
     shows "ga\<in>cr_ample_impl3 gci 
       \<and> (ga_ex_impl ga gci, ga_ex ga gc) \<in> global_config_rel"
   proof
     show G1: "ga\<in>cr_ample_impl3 gci"
       using cr_ample_impl3_refine[param_fo, OF GCI] GA by auto
     
     from cr_ample_impl3_sim_aux[OF GCI G1] show 
       "(ga_ex_impl ga gci, ga_ex ga gc) \<in> global_config_rel"
       by auto
   qed    
 
   sublocale impl3: sa "\<lparr> g_V = UNIV, g_E = ample_step_impl3, g_V0 = {pid_init_gc_impl},
       sa_L = pid_interp_gc_impl is_vis_var \<rparr>" by unfold_locales auto
 
   sublocale impl3_sim: lbisimulation 
     global_config_rel
     "\<lparr> g_V = UNIV, g_E = ample_step_impl3, g_V0 = {pid_init_gc_impl},
       sa_L = pid_interp_gc_impl is_vis_var \<rparr>"
     "\<lparr> g_V = UNIV, g_E = ample_step_impl2, g_V0 = {pid_init_gc},
       sa_L = pid_interp_gc \<rparr>"
     apply unfold_locales
     apply simp
     apply simp
     apply simp
     using pid_init_gc_impl
     apply (auto dest: fun_relD) []
     unfolding ample_step_impl2_def ample_step_impl3_def
     apply (auto dest: cr_ample_impl3_sim_aux) []
     using pid_interp_gc_impl
     apply (auto dest: fun_relD) []
     apply simp
     
     using pid_init_gc_impl
     apply (auto dest: fun_relD) []
     defer    
     using pid_interp_gc_impl
     apply (auto dest: fun_relD) []
     apply auto
 
     apply (auto dest: cr_ample_impl3_sim_aux2) []
     done
 
   text \<open>Correctness of impl3\<close>
   (* TODO: Locale hl_reduction seems very special, and we cannot use it here*)
   lemma impl3_accept_subset: "impl3.accept w \<Longrightarrow> lv.sa.accept w"
     using impl3_sim.accept_bisim cr_ample_impl2_reduction hl_reduction.ample_accept_subset
     by simp
 
   lemma impl3_accept_stuttering: "lv.sa.accept w \<Longrightarrow> \<exists>w'. w\<approx>w' \<and> impl3.accept w'"
     using impl3_sim.accept_bisim cr_ample_impl2_reduction hl_reduction.ample_accept_stuttering
     by simp
 
   text \<open>Next, we go from sets of actions to lists of actions\<close>
   definition (in cprog) "ga_gample_mil4 mem sticky_Ei (gc::pid_global_config_impl) = (
     let 
       lcs = pid_global_config.processes gc;
       gs = pid_global_config.state gc
     in
       collecti_index_list (\<lambda>_ lc. let
           c = local_config.command lc;
           ls = local_config.state lc;
           as = comp.succ_impl c;
           s = filter (la_en'_impl (ls,gs) o fst) as;
           ample = s\<noteq>[] 
           \<and> (\<forall>(a,_)\<in>set as. read_globals a = {} \<and> write_globals a = {}) 
           \<and> (\<forall>(a,c')\<in>set s. \<not>mem (c,c') sticky_Ei)
         in
           (ample,map (Pair c) s)
       ) lcs
   )"
 
   lemma ga_gample_mil4_refine:
     "(ga_gample_mil4, ga_gample_mi3) 
     \<in> (Id\<times>\<^sub>rId \<rightarrow> Id \<rightarrow> bool_rel) \<rightarrow> Id \<rightarrow> Id \<rightarrow> \<langle>nat_rel \<times>\<^sub>r Id\<rangle>list_set_rel"
     apply (intro fun_relI)
     unfolding ga_gample_mil4_def ga_gample_mi3_def
     apply (parametricity)
     apply simp
     apply (rule IdI)
     apply simp
     apply (rule IdI)
     apply (intro fun_relI)
     apply (rule collecti_index_list_refine[param_fo])
     apply (intro fun_relI)
     apply (simp add: list_set_rel_def br_def distinct_map 
       comp.succ_impl_invar)
     apply (auto simp: filter_empty_conv)
     apply force
     done
 
   definition (in cprog) "cr_ample_impl4 is_vis_var \<equiv>
     let sticky = find_fas_init_code (=) bounded_hashcode_nat
          (def_hashmap_size TYPE(nat)) cfgc_G_impl (is_vis_edge is_vis_var)
     in stutter_extend_en_list (ga_gample_mil4 (\<lambda>x f. f x) sticky)"
       
   lemma cr_ample_impl4_refine:
     "(cr_ample_impl4 is_vis_var, cr_ample_impl3)\<in>Id \<rightarrow> \<langle>\<langle>nat_rel \<times>\<^sub>r Id\<rangle>option_rel\<rangle>list_set_rel"
     unfolding cr_ample_impl4_def cr_ample_impl3_def
     apply (parametricity add: stutter_extend_en_list.refine ga_gample_mil4_refine)
     apply (simp_all add: is_vis_edge_correct)
     done
 
   text \<open>Finally, we combine the ample-implementation and the executable implementation
     to get a step function\<close>  
   definition (in cprog) "ample_step_impl4 is_vis_var \<equiv>
     rel_of_enex_list (cr_ample_impl4 is_vis_var,ga_ex_impl)"
 
   lemma ample_step_impl4: 
     "(ample_step_impl4 is_vis_var, ample_step_impl3) \<in> \<langle>Id \<times>\<^sub>r Id\<rangle> set_rel"
     unfolding ample_step_impl4_def ample_step_impl3_def rel_of_pred_def
     apply (parametricity add: rel_of_enex_list_refine cr_ample_impl4_refine[simplified])
     by auto
 
   sublocale impl4: sa "\<lparr> g_V = UNIV, g_E = ample_step_impl4 is_vis_var,
     g_V0 = {pid_init_gc_impl}, sa_L = pid_interp_gc_impl is_vis_var \<rparr>" by unfold_locales auto
 
   lemma impl4_accept_subset: "impl4.accept w \<Longrightarrow> lv.sa.accept w"
     using impl3_accept_subset ample_step_impl4
     by simp
 
   lemma impl4_accept_stuttering: "lv.sa.accept w \<Longrightarrow> \<exists>w'. w\<approx>w' \<and> impl4.accept w'"
     using impl3_accept_stuttering ample_step_impl4
     by simp
     
   lemma (in -) pred_of_succ_of_enex_list:
     fixes enex :: "('c \<Rightarrow> 'a list) \<times> ('a \<Rightarrow> 'c \<Rightarrow> 'c)"
     shows "pred_of_succ (set o succ_of_enex_list enex) = pred_of_enex_list enex"
   proof -
     { fix x and l
       have "glist_member (=) x l \<longleftrightarrow> x\<in>set l"
         by (induction l) auto
     } note [simp] = this
 
     {
       fix l :: "'a list" and g and l0
       have "set (foldli l (\<lambda>_. True) (\<lambda>x. glist_insert (=) (g x)) l0) = set l0 \<union> g`set l"
         by (induction l arbitrary: l0) (auto simp: glist_insert_def)
     } note [simp] = this
 
     {
       fix l::"'a list" and P i
       have "foldli l Not (\<lambda>x _. P x) i \<longleftrightarrow> i \<or> (\<exists>x\<in>set l. P x)"
         by (induction l arbitrary: i) auto
     } note [simp] = this
 
 
     show ?thesis
       unfolding succ_of_enex_list_def[abs_def] pred_of_enex_list_def[abs_def]
       by (auto simp: pred_of_succ_def gen_image_def gen_bex_def intro!: ext)
   qed    
   lemma (in -) rel_of_succ_of_enex_list:
     fixes enex :: "('c \<Rightarrow> 'a list) \<times> ('a \<Rightarrow> 'c \<Rightarrow> 'c)"
     shows "rel_of_succ (set o succ_of_enex_list enex) = rel_of_enex_list enex"
     unfolding rel_of_enex_list_def
     unfolding pred_of_succ_of_enex_list[symmetric]
     by simp
 
   definition (in cprog) "impl4_succ is_vis_var
     \<equiv> succ_of_enex_list (cr_ample_impl4 is_vis_var,ga_ex_impl)"
   lemma impl4_succ_pred: 
     "rel_of_succ (set o (impl4_succ is_vis_var)) = ample_step_impl4 is_vis_var"
     unfolding impl4_succ_def ample_step_impl4_def 
     by (simp add: rel_of_succ_of_enex_list)
     
 end
 
 export_code ga_ex_impl checking SML
 
 definition "ccfg_E_succ_impl mst \<equiv> remdups o map snd o ccfg_succ_impl mst"
 
 lemma (in cprog) ccfg_E_succ_impl: "ccfg_E_succ_impl (comp_info_of prog) = cfgc_E_succ"
   apply (intro ext) 
   unfolding ccfg_E_succ_impl_def cfgc_E_succ_def
   by (simp add: ccfg_succ_impl)
 
 
 definition init_pc_impl_impl :: "comp_info \<Rightarrow> proc_decl \<Rightarrow> local_config_impl" where
   "init_pc_impl_impl mst pd \<equiv> \<lparr>
     local_config.command = comp_\<gamma>_impl mst (proc_decl.body pd),
     local_config.state = \<lparr>
       local_state_impl.variables = init_valuation_impl (proc_decl.local_vars pd)
     \<rparr>
   \<rparr>"
 
 lemma (in cprog) init_pc_impl_impl: "init_pc_impl_impl (comp_info_of prog) = init_pc_impl"
   apply (intro ext)
   unfolding init_pc_impl_impl_def init_pc_impl_def
   by (simp add: comp_\<gamma>_impl)
 
 definition pid_init_gc_impl_impl :: "program \<Rightarrow> comp_info \<Rightarrow> pid_global_config_impl" where
   "pid_init_gc_impl_impl prog mst \<equiv> \<lparr>
     pid_global_config.processes = (map (init_pc_impl_impl mst) (program.processes prog)),
     pid_global_config.state = \<lparr>
       global_state_impl.variables = init_valuation_impl (program.global_vars prog)
     \<rparr>
   \<rparr>"
 
 lemma (in cprog) pid_init_gc_impl_impl: 
   "pid_init_gc_impl_impl prog (comp_info_of prog) = pid_init_gc_impl"
   unfolding pid_init_gc_impl_impl_def pid_init_gc_impl_def
   by (simp add: init_pc_impl_impl)
 
 definition "ccfg_V0_impl prog mst \<equiv> map (comp_\<gamma>_impl mst) (cfg_V0_list prog)"
 
 lemma (in cprog) ccfg_V0_impl: "ccfg_V0_impl prog (comp_info_of prog) = cfgc_V0_list"
   unfolding ccfg_V0_impl_def cfgc_V0_list_def
   by (simp add: comp_\<gamma>_impl)
 
 definition "ccfg_G_impl_impl prog mst \<equiv>
   \<lparr> gi_V = \<lambda> _. True, gi_E = ccfg_E_succ_impl mst, gi_V0 = ccfg_V0_impl prog mst \<rparr>"
 
 lemma (in cprog) ccfg_G_impl_impl: "ccfg_G_impl_impl prog (comp_info_of prog) = cfgc_G_impl"
   unfolding ccfg_G_impl_impl_def cfgc_G_impl_def
   unfolding ccfg_E_succ_impl ccfg_V0_impl
   by rule
 
 definition "is_vis_edge_impl mst is_vis_var \<equiv> \<lambda>(c,c'). 
   \<exists>(a,cc')\<in>set (ccfg_succ_impl mst c). c'=cc' \<and> (\<exists>v\<in>write_globals a. is_vis_var v)"
 
 lemma (in cprog) is_vis_edge_impl: "is_vis_edge_impl (comp_info_of prog) = is_vis_edge"
   apply (intro ext)
   unfolding is_vis_edge_impl_def is_vis_edge_def
   by (simp add: ccfg_succ_impl)
 
 definition "ga_gample_mil4_impl mst mem sticky_Ei (gc::pid_global_config_impl) = (
   let 
     lcs = pid_global_config.processes gc;
     gs = pid_global_config.state gc
   in
     collecti_index_list (\<lambda>_ lc. let
         c = local_config.command lc;
         ls = local_config.state lc;
         as = ccfg_succ_impl mst c;
         s = filter (la_en'_impl (ls,gs) o fst) as;
         ample = s\<noteq>[] 
         \<and> (\<forall>(a,_)\<in>set as. read_globals a = {} \<and> write_globals a = {}) 
         \<and> (\<forall>(a,c')\<in>set s. \<not>mem (c,c') sticky_Ei)
       in
         (ample,map (Pair c) s)
     ) lcs
 )"
 
 lemma (in cprog) ga_gample_mil4_impl: "ga_gample_mil4_impl (comp_info_of prog) = ga_gample_mil4"
   apply (intro ext)
   unfolding ga_gample_mil4_impl_def ga_gample_mil4_def
   by (simp add: ccfg_succ_impl)
 
 
 definition "cr_ample_impl4_impl prog mst is_vis_var \<equiv>
   let sticky = find_fas_init_code (=) bounded_hashcode_nat
        (def_hashmap_size TYPE(nat)) (ccfg_G_impl_impl prog mst)
        (is_vis_edge_impl mst is_vis_var)
   in stutter_extend_en_list (ga_gample_mil4_impl mst (\<lambda>x f. f x) sticky)"
 
 lemma (in cprog) cr_ample_impl4_impl: "cr_ample_impl4_impl prog (comp_info_of prog) = cr_ample_impl4"
   apply (intro ext)
   unfolding cr_ample_impl4_impl_def cr_ample_impl4_def
   by (simp add: ga_gample_mil4_impl ccfg_G_impl_impl is_vis_edge_impl)
 
 definition "impl4_succ_impl prog mst is_vis_var
     \<equiv> succ_of_enex_list (cr_ample_impl4_impl prog mst is_vis_var,ga_ex_impl)"
 
 lemma (in cprog) impl4_succ_impl: 
   "impl4_succ_impl prog (comp_info_of prog) = impl4_succ"
   apply (intro ext)
   unfolding impl4_succ_impl_def impl4_succ_def
   by (simp add: cr_ample_impl4_impl)
 
 definition "ample_step_impl4_impl prog mst is_vis_var 
   \<equiv> rel_of_enex_list (cr_ample_impl4_impl prog mst is_vis_var,ga_ex_impl)"
 
 lemma (in cprog) ample_step_impl4_impl: 
   "ample_step_impl4_impl prog (comp_info_of prog) = ample_step_impl4"
   apply (intro ext)
   unfolding ample_step_impl4_impl_def ample_step_impl4_def
   by (simp add: cr_ample_impl4_impl)
   
 export_code impl4_succ_impl pid_init_gc_impl_impl comp_info_of checking SML
 
 end
 
diff --git a/thys/Native_Word/Code_Target_Word_Base.thy b/thys/Native_Word/Code_Target_Word_Base.thy
--- a/thys/Native_Word/Code_Target_Word_Base.thy
+++ b/thys/Native_Word/Code_Target_Word_Base.thy
@@ -1,449 +1,429 @@
 (*  Title:      Code_Target_Word_Base.thy
     Author:     Andreas Lochbihler, ETH Zurich
 *)
 
 chapter \<open>Common base for target language implementations of word types\<close>
 
 theory Code_Target_Word_Base imports
   "HOL-Word.Word"
+  "Word_Lib.Word_Lib"
   Bits_Integer
 begin
 
+(* TODO: Move to Word ? *)
+lemma dflt_size_word_pow_ne_zero [simp]:
+  "(2 :: 'a word) ^ (LENGTH('a::len) - Suc 0) \<noteq> 0"
+  by (simp add: not_le)
+
 text \<open>More lemmas\<close>
 
 lemma nat_div_eq_Suc_0_iff: "n div m = Suc 0 \<longleftrightarrow> m \<le> n \<and> n < 2 * m"
   apply auto
   using div_greater_zero_iff apply fastforce
    apply (metis One_nat_def div_greater_zero_iff dividend_less_div_times mult.right_neutral mult_Suc mult_numeral_1 numeral_2_eq_2 zero_less_numeral)
   apply (simp add: div_nat_eqI)
   done
 
 lemma Suc_0_lt_2p_len_of: "Suc 0 < 2 ^ LENGTH('a :: len)"
   by (metis One_nat_def len_gt_0 lessI numeral_2_eq_2 one_less_power)
 
 lemma div_half_nat:
   fixes x y :: nat
   assumes "y \<noteq> 0"
   shows "(x div y, x mod y) = (let q = 2 * (x div 2 div y); r = x - q * y in if y \<le> r then (q + 1, r - y) else (q, r))"
 proof -
   let ?q = "2 * (x div 2 div y)"
   have q: "?q = x div y - x div y mod 2"
     by(metis div_mult2_eq mult.commute minus_mod_eq_mult_div [symmetric])
   let ?r = "x - ?q * y"
   have r: "?r = x mod y + x div y mod 2 * y"
     by(simp add: q diff_mult_distrib minus_mod_eq_div_mult [symmetric])(metis diff_diff_cancel mod_less_eq_dividend mod_mult2_eq add.commute mult.commute)
 
   show ?thesis
   proof(cases "y \<le> x - ?q * y")
     case True
     with assms q have "x div y mod 2 \<noteq> 0" unfolding r
       by (metis Nat.add_0_right diff_0_eq_0 diff_Suc_1 le_div_geq mod2_gr_0 mod_div_trivial mult_0 neq0_conv numeral_1_eq_Suc_0 numerals(1)) 
     hence "x div y = ?q + 1" unfolding q
       by simp
     moreover hence "x mod y = ?r - y"
       by simp(metis minus_div_mult_eq_mod [symmetric] diff_commute diff_diff_left mult_Suc)
     ultimately show ?thesis using True by(simp add: Let_def)
   next
     case False
     hence "x div y mod 2 = 0" unfolding r
       by(simp add: not_le)(metis Nat.add_0_right assms div_less div_mult_self2 mod_div_trivial mult.commute)
     hence "x div y = ?q" unfolding q by simp
     moreover hence "x mod y = ?r" by (metis minus_div_mult_eq_mod [symmetric])
     ultimately show ?thesis using False by(simp add: Let_def)
   qed
 qed
 
 lemma unat_p2: "n < LENGTH('a :: len) \<Longrightarrow> unat (2 ^ n :: 'a word) = 2 ^ n"
 proof(induct n)
   case 0 thus ?case by simp
 next
   case (Suc n)
   then obtain n' where "LENGTH('a) = Suc n'" by(cases "LENGTH('a)") simp_all
   with Suc show ?case by (simp add: unat_word_ariths bintrunc_mod2p)
 qed
 
 lemma word_div_lt_eq_0:
   "x < y \<Longrightarrow> x div y = 0" for x :: "'a :: len word"
   by (simp add: word_eq_iff word_less_def word_test_bit_def uint_div)
 
 lemma word_div_eq_1_iff: "n div m = 1 \<longleftrightarrow> n \<ge> m \<and> unat n < 2 * unat (m :: 'a :: len word)"
 apply(simp only: word_arith_nat_defs word_le_nat_alt nat_div_eq_Suc_0_iff[symmetric])
 apply(rule word_unat.Abs_inject)
  apply(simp only: unat_div[symmetric] word_unat.Rep)
 apply(simp add: unats_def Suc_0_lt_2p_len_of)
 done
 
 lemma div_half_word:
   fixes x y :: "'a :: len word"
   assumes "y \<noteq> 0"
   shows "(x div y, x mod y) = (let q = (x >> 1) div y << 1; r = x - q * y in if y \<le> r then (q + 1, r - y) else (q, r))"
 proof -
   obtain n where n: "x = of_nat n" "n < 2 ^ LENGTH('a)"
     by (rule that [of \<open>unat x\<close>]) simp_all
   moreover obtain m where m: "y = of_nat m" "m < 2 ^ LENGTH('a)"
     by (rule that [of \<open>unat y\<close>]) simp_all
   ultimately have [simp]: \<open>unat (of_nat n :: 'a word) = n\<close> \<open>unat (of_nat m :: 'a word) = m\<close>
     by (transfer, simp add: take_bit_of_nat take_bit_nat_eq_self_iff)+
   let ?q = "(x >> 1) div y << 1"
   let ?q' = "2 * (n div 2 div m)"
   have "n div 2 div m < 2 ^ LENGTH('a)" using n by (metis of_nat_inverse unat_lt2p uno_simps(2))
   hence q: "?q = of_nat ?q'" using n m
     by (auto simp add: shiftr_word_eq drop_bit_eq_div shiftl_t2n word_arith_nat_div uno_simps take_bit_nat_eq_self)
   from assms have "m \<noteq> 0" using m by -(rule notI, simp)
 
   from n have "2 * (n div 2 div m) < 2 ^ LENGTH('a)"
     by(metis mult.commute div_mult2_eq minus_mod_eq_mult_div [symmetric] less_imp_diff_less of_nat_inverse unat_lt2p uno_simps(2))
   moreover
   have "2 * (n div 2 div m) * m < 2 ^ LENGTH('a)" using n unfolding div_mult2_eq[symmetric]
     by(subst (2) mult.commute)(simp add: minus_mod_eq_div_mult [symmetric] diff_mult_distrib minus_mod_eq_mult_div [symmetric] div_mult2_eq)
   moreover have "2 * (n div 2 div m) * m \<le> n"
     by (metis div_mult2_eq dtle mult.assoc mult.left_commute)
   ultimately
   have r: "x - ?q * y = of_nat (n - ?q' * m)"
     and "y \<le> x - ?q * y \<Longrightarrow> of_nat (n - ?q' * m) - y = of_nat (n - ?q' * m - m)"
     using n m unfolding q
      apply (simp_all add: of_nat_diff)
     apply (subst of_nat_diff)
     apply (simp_all add: word_le_nat_alt take_bit_nat_eq_self unat_sub_if' unat_word_ariths)
     apply (cases \<open>2 \<le> LENGTH('a)\<close>)
     apply (simp_all add: unat_word_ariths take_bit_nat_eq_self)
     done
   then show ?thesis using n m div_half_nat [OF \<open>m \<noteq> 0\<close>, of n] unfolding q
     by (simp add: word_le_nat_alt word_div_def word_mod_def Let_def take_bit_nat_eq_self
       flip: zdiv_int zmod_int
       split del: if_split split: if_split_asm)
 qed
 
 lemma word_test_bit_set_bits: "(BITS n. f n :: 'a :: len word) !! n \<longleftrightarrow> n < LENGTH('a) \<and> f n"
   by (simp add: test_bit_eq_bit bit_set_bits_word_iff)
 
 lemma word_of_int_conv_set_bits: "word_of_int i = (BITS n. i !! n)"
   by (rule word_eqI) (auto simp add: word_test_bit_set_bits test_bit.eq_norm)
 
 lemma word_and_mask_or_conv_and_mask:
   "n !! index \<Longrightarrow> (n AND mask index) OR (1 << index) = n AND mask (index + 1)"
   for n :: \<open>'a::len word\<close>
 by(rule word_eqI)(auto simp add: word_ao_nth word_size nth_shiftl simp del: shiftl_1)
 
 lemma uint_and_mask_or_full:
   fixes n :: "'a :: len word"
   assumes "n !! (LENGTH('a) - 1)"
   and "mask1 = mask (LENGTH('a) - 1)"
   and "mask2 = 1 << LENGTH('a) - 1"
   shows "uint (n AND mask1) OR mask2 = uint n"
 proof -
   have "mask2 = uint (1 << LENGTH('a) - 1 :: 'a word)" using assms
     by (simp add: uint_shiftl word_size bintrunc_shiftl del: shiftl_1)
   hence "uint (n AND mask1) OR mask2 = uint (n AND mask1 OR (1 << LENGTH('a) - 1 :: 'a word))"
     by(simp add: uint_or)
   also have "\<dots> = uint (n AND mask (LENGTH('a) - 1 + 1))"
     using assms by(simp only: word_and_mask_or_conv_and_mask)
   also have "\<dots> = uint n" by simp
   finally show ?thesis .
 qed
 
 
 text \<open>Division on @{typ "'a word"} is unsigned, but Scala and OCaml only have signed division and modulus.\<close>
 
-definition word_sdiv :: "'a :: len word \<Rightarrow> 'a word \<Rightarrow> 'a word" (infixl "sdiv" 70)
-where [code]:
+lemmas word_sdiv_def = sdiv_word_def
+lemmas word_smod_def = smod_word_def
+
+lemma [code]:
   "x sdiv y =
    (let x' = sint x; y' = sint y;
         negative = (x' < 0) \<noteq> (y' < 0);
         result = abs x' div abs y'
     in word_of_int (if negative then -result else result))"
+  for x y :: \<open>'a::len word\<close>
+  by (simp add: sdiv_word_def signed_divide_int_def sgn_if Let_def not_less not_le)
 
-definition word_smod :: "'a :: len word \<Rightarrow> 'a word \<Rightarrow> 'a word" (infixl "smod" 70)
-where [code]:
+lemma [code]:
   "x smod y =
    (let x' = sint x; y' = sint y;
         negative = (x' < 0);
         result = abs x' mod abs y'
     in word_of_int (if negative then -result else result))"
-
-lemma sdiv_smod_id: "(a sdiv b) * b + (a smod b) = a"
+  for x y :: \<open>'a::len word\<close>
 proof -
-  note [simp] = word_sdiv_def word_smod_def
-  have F5: "\<forall>u::'a word. - (- u) = u" by (metis minus_minus)
-  have F7: "\<forall>v u::'a word. u + v = v + u" by(metis add.left_commute add_0_right)
-  have F8: "\<forall>(w::'a word) (v::int) u::int. word_of_int u + word_of_int v * w = word_of_int (u + v * sint w)"
-    by (metis word_sint.Rep_inverse wi_hom_syms(1) wi_hom_syms(3))
-  have "\<exists>u. u = - sint b \<and> word_of_int (sint a mod u + - (- u * (sint a div u))) = a"
-    using F5 by (metis minus_minus word_sint.Rep_inverse' mult_minus_left add.commute mult_div_mod_eq [symmetric])
-  hence "word_of_int (sint a mod - sint b + - (sint b * (sint a div - sint b))) = a" by (metis equation_minus_iff)
-  hence "word_of_int (sint a mod - sint b) + word_of_int (- (sint a div - sint b)) * b = a"
-    using F8 by(metis mult.commute mult_minus_left)
-  hence eq: "word_of_int (- (sint a div - sint b)) * b + word_of_int (sint a mod - sint b) = a" using F7 by metis
-
+  have *: \<open>k mod l = k - k div l * l\<close> for k l :: int
+    by (simp add: minus_div_mult_eq_mod)
   show ?thesis
-  proof(cases "sint a < 0")
-    case True note a = this
-    show ?thesis
-    proof(cases "sint b < 0")
-      case True
-      with a show ?thesis
-        by simp (metis F7 F8 eq minus_equation_iff minus_mult_minus mod_div_mult_eq)
-    next
-      case False
-      from eq have "word_of_int (- (- sint a div sint b)) * b + word_of_int (- (- sint a mod sint b)) = a"
-        by (metis div_minus_right mod_minus_right)
-      with a False show ?thesis by simp
-    qed
-  next
-    case False note a = this
-    show ?thesis
-    proof(cases "sint b < 0")
-      case True
-      with a eq show ?thesis by simp
-    next
-      case False with a show ?thesis
-        by simp (metis wi_hom_add wi_hom_mult add.commute mult.commute word_sint.Rep_inverse add.commute mult_div_mod_eq [symmetric])
-    qed
-  qed
+    by (simp add: smod_word_def signed_modulo_int_def signed_divide_int_def * sgn_if) (simp add: signed_eq_0_iff)
 qed
 
 text \<open>
   This algorithm implements unsigned division in terms of signed division.
   Taken from Hacker's Delight.
 \<close>
 
 lemma divmod_via_sdivmod:
   fixes x y :: "'a :: len word"
   assumes "y \<noteq> 0"
   shows
   "(x div y, x mod y) =
   (if 1 << (LENGTH('a) - 1) \<le> y then if x < y then (0, x) else (1, x - y)
    else let q = ((x >> 1) sdiv y) << 1;
             r = x - q * y
         in if r \<ge> y then (q + 1, r - y) else (q, r))"
 proof(cases "1 << (LENGTH('a) - 1) \<le> y")
   case True
   note y = this
   show ?thesis
   proof(cases "x < y")
     case True
     then have "x mod y = x"
       by (cases x, cases y) (simp add: word_less_def word_mod_def)
     thus ?thesis using True y by(simp add: word_div_lt_eq_0)
   next
     case False
     obtain n where n: "y = of_nat n" "n < 2 ^ LENGTH('a)"
       by (rule that [of \<open>unat y\<close>]) simp_all
     have "unat x < 2 ^ LENGTH('a)" by(rule unat_lt2p)
     also have "\<dots> = 2 * 2 ^ (LENGTH('a) - 1)"
       by(metis Suc_pred len_gt_0 power_Suc One_nat_def)
     also have "\<dots> \<le> 2 * n" using y n
       by transfer (simp add: push_bit_of_1 take_bit_eq_mod)
     finally have div: "x div of_nat n = 1" using False n
       by (simp add: word_div_eq_1_iff take_bit_nat_eq_self)
     moreover have "x mod y = x - x div y * y"
       by (simp add: minus_div_mult_eq_mod)
     with div n have "x mod y = x - y" by simp
     ultimately show ?thesis using False y n by simp
   qed
 next
   case False
   note y = this
   obtain n where n: "x = of_nat n" "n < 2 ^ LENGTH('a)"
     by (rule that [of \<open>unat x\<close>]) simp_all
   hence "int n div 2 + 2 ^ (LENGTH('a) - Suc 0) < 2 ^ LENGTH('a)"
     by (cases "LENGTH('a)")
       (simp_all, simp only: of_nat_numeral [where ?'a = int, symmetric]
       zdiv_int [symmetric] of_nat_power [symmetric])
   with y n have "sint (x >> 1) = uint (x >> 1)"
     by (simp add: sint_uint sbintrunc_mod2p shiftr_div_2n take_bit_nat_eq_self)
   moreover have "uint y + 2 ^ (LENGTH('a) - Suc 0) < 2 ^ LENGTH('a)"
     using y by (cases "LENGTH('a)")
       (simp_all add: not_le word_2p_lem word_size)
   then have "sint y = uint y"
     by (simp add: sint_uint sbintrunc_mod2p)
   ultimately show ?thesis using y
-    by(subst div_half_word[OF assms])(simp add: word_sdiv_def uint_div[symmetric])
+    apply (subst div_half_word [OF assms])
+    apply (simp add: sdiv_word_def signed_divide_int_def flip: uint_div)
+    done
 qed
 
 
 text \<open>More implementations tailored towards target-language implementations\<close>
 
 context
 includes integer.lifting
 begin
 lift_definition word_of_integer :: "integer \<Rightarrow> 'a :: len word" is word_of_int .
 
 lemma word_of_integer_code [code]: "word_of_integer n = word_of_int (int_of_integer n)"
 by(simp add: word_of_integer.rep_eq)
 end
 
 lemma word_of_int_code:
   "uint (word_of_int x :: 'a word) = x AND mask (LENGTH('a :: len))"
   by (simp add: take_bit_eq_mask)
 
 context fixes f :: "nat \<Rightarrow> bool" begin
 
 definition set_bits_aux :: \<open>'a word \<Rightarrow> nat \<Rightarrow> 'a :: len word\<close>
   where \<open>set_bits_aux w n = push_bit n w OR take_bit n (set_bits f)\<close>
 
 lemma set_bits_aux_conv:
   \<open>set_bits_aux w n = (w << n) OR (set_bits f AND mask n)\<close>
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI)
-    (auto simp add: set_bits_aux_def shiftl_word_eq bit_and_iff bit_or_iff bit_push_bit_iff bit_take_bit_iff bit_mask_iff bit_set_bits_word_iff exp_eq_zero_iff)
+    (auto simp add: set_bits_aux_def shiftl_word_eq bit_and_iff bit_or_iff bit_push_bit_iff bit_take_bit_iff bit_mask_iff bit_set_bits_word_iff)
 
 corollary set_bits_conv_set_bits_aux:
   \<open>set_bits f = (set_bits_aux 0 (LENGTH('a)) :: 'a :: len word)\<close>
   by (simp add: set_bits_aux_conv)
 
 lemma set_bits_aux_0 [simp]:
   \<open>set_bits_aux w 0 = w\<close>
   by  (simp add: set_bits_aux_conv)
 
 lemma set_bits_aux_Suc [simp]:
   \<open>set_bits_aux w (Suc n) = set_bits_aux ((w << 1) OR (if f n then 1 else 0)) n\<close>
   by (simp add: set_bits_aux_def shiftl_word_eq bit_eq_iff bit_or_iff bit_push_bit_iff bit_take_bit_iff bit_set_bits_word_iff)
-    (auto simp add: bit_exp_iff not_less bit_1_iff less_Suc_eq_le exp_eq_zero_iff)
+    (auto simp add: bit_exp_iff not_less bit_1_iff less_Suc_eq_le)
 
 lemma set_bits_aux_simps [code]:
   \<open>set_bits_aux w 0 = w\<close>
   \<open>set_bits_aux w (Suc n) = set_bits_aux ((w << 1) OR (if f n then 1 else 0)) n\<close>
   by simp_all
 
 end
 
 lemma word_of_int_via_signed:
   fixes mask
   assumes mask_def: "mask = Bit_Operations.mask (LENGTH('a))"
   and shift_def: "shift = 1 << LENGTH('a)"
   and index_def: "index = LENGTH('a) - 1"
   and overflow_def:"overflow = 1 << (LENGTH('a) - 1)"
   and least_def: "least = - overflow"
   shows
   "(word_of_int i :: 'a :: len word) =
    (let i' = i AND mask
     in if i' !! index then
          if i' - shift < least \<or> overflow \<le> i' - shift then arbitrary1 i' else word_of_int (i' - shift)
        else if i' < least \<or> overflow \<le> i' then arbitrary2 i' else word_of_int i')"
 proof -
   define i' where "i' = i AND mask"
   have "shift = mask + 1" unfolding assms by(simp add: bin_mask_p1_conv_shift)
   hence "i' < shift" by(simp add: mask_def i'_def int_and_le)
   show ?thesis
   proof(cases "i' !! index")
     case True
-    hence unf: "i' = overflow OR i'" unfolding assms i'_def
-      by(auto intro!: bin_eqI simp add: bin_nth_ops)
+    then have unf: "i' = overflow OR i'"
+      apply (simp add: assms i'_def shiftl_eq_push_bit push_bit_of_1 flip: take_bit_eq_mask)
+      apply (rule bit_eqI)
+      apply (auto simp add: bit_take_bit_iff bit_or_iff bit_exp_iff)
+      done
     have "overflow \<le> i'" by(subst unf)(rule le_int_or, simp add: bin_sign_and assms i'_def)
     hence "i' - shift < least \<longleftrightarrow> False" unfolding assms
       by(cases "LENGTH('a)")(simp_all add: not_less)
     moreover
     have "overflow \<le> i' - shift \<longleftrightarrow> False" using \<open>i' < shift\<close> unfolding assms
       by(cases "LENGTH('a)")(auto simp add: not_le elim: less_le_trans)
     moreover
     have "word_of_int (i' - shift) = (word_of_int i :: 'a word)" using \<open>i' < shift\<close>
       by (simp add: i'_def shift_def mask_def shiftl_eq_push_bit push_bit_of_1 flip: take_bit_eq_mask)
     ultimately show ?thesis using True by(simp add: Let_def i'_def)
   next
     case False
     hence "i' = i AND Bit_Operations.mask (LENGTH('a) - 1)" unfolding assms i'_def
       by(clarsimp simp add: i'_def bin_nth_ops intro!: bin_eqI)(cases "LENGTH('a)", auto simp add: less_Suc_eq)
     also have "\<dots> \<le> Bit_Operations.mask (LENGTH('a) - 1)" by(rule int_and_le) simp
     also have "\<dots> < overflow" unfolding overflow_def
       by(simp add: bin_mask_p1_conv_shift[symmetric])
     also
     have "least \<le> 0" unfolding least_def overflow_def by simp
     have "0 \<le> i'" by (simp add: i'_def mask_def)
     hence "least \<le> i'" using \<open>least \<le> 0\<close> by simp
     moreover
     have "word_of_int i' = (word_of_int i :: 'a word)"
       by(rule word_eqI)(auto simp add: i'_def bin_nth_ops mask_def)
     ultimately show ?thesis using False by(simp add: Let_def i'_def)
   qed
 qed
 
 
 
 text \<open>Quickcheck conversion functions\<close>
 
 notation scomp (infixl "\<circ>\<rightarrow>" 60)
 
 definition qc_random_cnv ::
   "(natural \<Rightarrow> 'a::term_of) \<Rightarrow> natural \<Rightarrow> Random.seed
     \<Rightarrow> ('a \<times> (unit \<Rightarrow> Code_Evaluation.term)) \<times> Random.seed"
   where "qc_random_cnv a_of_natural i = Random.range (i + 1) \<circ>\<rightarrow> (\<lambda>k. Pair (
        let n = a_of_natural k
        in (n, \<lambda>_. Code_Evaluation.term_of n)))"
 
 no_notation scomp (infixl "\<circ>\<rightarrow>" 60)
 
 definition qc_exhaustive_cnv :: "(natural \<Rightarrow> 'a) \<Rightarrow> ('a \<Rightarrow> (bool \<times> term list) option)
   \<Rightarrow> natural \<Rightarrow> (bool \<times> term list) option"
 where
   "qc_exhaustive_cnv a_of_natural f d =
    Quickcheck_Exhaustive.exhaustive (%x. f (a_of_natural x)) d"
 
 definition qc_full_exhaustive_cnv ::
   "(natural \<Rightarrow> ('a::term_of)) \<Rightarrow> ('a \<times> (unit \<Rightarrow> term) \<Rightarrow> (bool \<times> term list) option)
   \<Rightarrow> natural \<Rightarrow> (bool \<times> term list) option"
 where
   "qc_full_exhaustive_cnv a_of_natural f d = Quickcheck_Exhaustive.full_exhaustive
   (%(x, xt). f (a_of_natural x, %_. Code_Evaluation.term_of (a_of_natural x))) d"
 
 declare [[quickcheck_narrowing_ghc_options = "-XTypeSynonymInstances"]]
 
 definition qc_narrowing_drawn_from :: "'a list \<Rightarrow> integer \<Rightarrow> _"
 where
   "qc_narrowing_drawn_from xs =
    foldr Quickcheck_Narrowing.sum (map Quickcheck_Narrowing.cons (butlast xs)) (Quickcheck_Narrowing.cons (last xs))"
 
 locale quickcheck_narrowing_samples =
   fixes a_of_integer :: "integer \<Rightarrow> 'a \<times> 'a :: {partial_term_of, term_of}"
   and zero :: "'a"
   and tr :: "typerep"
 begin
 
 function narrowing_samples :: "integer \<Rightarrow> 'a list"
 where
   "narrowing_samples i =
    (if i > 0 then let (a, a') = a_of_integer i in narrowing_samples (i - 1) @ [a, a'] else [zero])"
 by pat_completeness auto
 termination including integer.lifting
 proof(relation "measure nat_of_integer")
   fix i :: integer
   assume "0 < i"
   thus "(i - 1, i) \<in> measure nat_of_integer"
     by simp(transfer, simp)
 qed simp
 
 definition partial_term_of_sample :: "integer \<Rightarrow> 'a"
 where
   "partial_term_of_sample i =
   (if i < 0 then undefined
    else if i = 0 then zero
    else if i mod 2 = 0 then snd (a_of_integer (i div 2))
    else fst (a_of_integer (i div 2 + 1)))"
 
 lemma partial_term_of_code:
   "partial_term_of (ty :: 'a itself) (Quickcheck_Narrowing.Narrowing_variable p t) \<equiv>
     Code_Evaluation.Free (STR ''_'') tr"
   "partial_term_of (ty :: 'a itself) (Quickcheck_Narrowing.Narrowing_constructor i []) \<equiv>
    Code_Evaluation.term_of (partial_term_of_sample i)"
 by (rule partial_term_of_anything)+
 
 end
 
 lemmas [code] =
   quickcheck_narrowing_samples.narrowing_samples.simps
   quickcheck_narrowing_samples.partial_term_of_sample_def
 
 
 text \<open>
   The separate code target \<open>SML_word\<close> collects setups for the
   code generator that PolyML does not provide.
 \<close>
 
 setup \<open>Code_Target.add_derived_target ("SML_word", [(Code_ML.target_SML, I)])\<close>
 
 code_identifier code_module Code_Target_Word_Base \<rightharpoonup>
   (SML) Word and (Haskell) Word and (OCaml) Word and (Scala) Word
 
 export_code signed_take_bit \<open>mask :: nat \<Rightarrow> int\<close> in SML module_name Code
 
 end
diff --git a/thys/Native_Word/ROOT b/thys/Native_Word/ROOT
--- a/thys/Native_Word/ROOT
+++ b/thys/Native_Word/ROOT
@@ -1,37 +1,38 @@
 chapter AFP
 
 session "Native_Word" (AFP) = "HOL-Word" +
   options [timeout = 2400]
   sessions
+    "Word_Lib"
     "HOL-Imperative_HOL"
   theories
     Code_Target_Bits_Int
     Uint64
     Uint32
     Uint16
     Uint8
     Uint
     Native_Cast
     Native_Cast_Uint
     Native_Word_Imperative_HOL
     Native_Word_Test_Emu
     Native_Word_Test_PolyML
     Native_Word_Test_PolyML2
     Native_Word_Test_PolyML64
     Native_Word_Test_Scala
   theories [condition = ISABELLE_GHC]
     Native_Word_Test_GHC
   theories [condition = ISABELLE_MLTON]
     Native_Word_Test_MLton
     Native_Word_Test_MLton2
   theories [condition = ISABELLE_OCAMLFIND]
     Native_Word_Test_OCaml
     Native_Word_Test_OCaml2
   theories [condition = ISABELLE_SMLNJ]
     Native_Word_Test_SMLNJ
     Native_Word_Test_SMLNJ2
   theories
     Uint_Userguide
   document_files
     "root.tex"
     "root.bib"
diff --git a/thys/Native_Word/Uint.thy b/thys/Native_Word/Uint.thy
--- a/thys/Native_Word/Uint.thy
+++ b/thys/Native_Word/Uint.thy
@@ -1,883 +1,875 @@
 (*  Title:      Uint.thy
     Author:     Peter Lammich, TU Munich
     Author:     Andreas Lochbihler, ETH Zurich
 *)
 
 chapter \<open>Unsigned words of default size\<close>
 
 theory Uint imports
   Code_Target_Word_Base
 begin
 
 text \<open>
   This theory provides access to words in the target languages of the code generator
   whose bit width is the default of the target language. To that end, the type \<open>uint\<close>
   models words of width \<open>dflt_size\<close>, but \<open>dflt_size\<close> is known only to be positive.
 
   Usage restrictions:
   Default-size words (type \<open>uint\<close>) cannot be used for evaluation, because 
   the results depend on the particular choice of word size in the target language
   and implementation. Symbolic evaluation has not yet been set up for \<open>uint\<close>.
 \<close>
 
 text \<open>The default size type\<close>
 typedecl dflt_size
 
 instantiation dflt_size :: typerep begin
 definition "typerep_class.typerep \<equiv>  \<lambda>_ :: dflt_size itself. Typerep.Typerep (STR ''Uint.dflt_size'') []"
 instance ..
 end
 
 consts dflt_size_aux :: "nat"
 specification (dflt_size_aux) dflt_size_aux_g0: "dflt_size_aux > 0"
   by auto
 hide_fact dflt_size_aux_def
 
 instantiation dflt_size :: len begin
 definition "len_of_dflt_size (_ :: dflt_size itself) \<equiv> dflt_size_aux"
 instance by(intro_classes)(simp add: len_of_dflt_size_def dflt_size_aux_g0)
 end
 
 abbreviation "dflt_size \<equiv> len_of (TYPE (dflt_size))"
 
 context includes integer.lifting begin
 lift_definition dflt_size_integer :: integer is "int dflt_size" .
 declare dflt_size_integer_def[code del]
   \<comment> \<open>The code generator will substitute a machine-dependent value for this constant\<close>
 
 lemma dflt_size_by_int[code]: "dflt_size = nat_of_integer dflt_size_integer"
 by transfer simp
 
 lemma dflt_size[simp]: 
   "dflt_size > 0"
   "dflt_size \<ge> Suc 0"
   "\<not> dflt_size < Suc 0"
   using len_gt_0[where 'a=dflt_size]
   by (simp_all del: len_gt_0)
 end
 
 declare prod.Quotient[transfer_rule]
 
 section \<open>Type definition and primitive operations\<close>
 
 typedef uint = "UNIV :: dflt_size word set" .. 
 
 setup_lifting type_definition_uint
 
 text \<open>Use an abstract type for code generation to disable pattern matching on @{term Abs_uint}.\<close>
 declare Rep_uint_inverse[code abstype]
 
 declare Quotient_uint[transfer_rule]
 
 instantiation uint :: comm_ring_1
 begin
 lift_definition zero_uint :: uint is "0 :: dflt_size word" .
 lift_definition one_uint :: uint is "1" .
 lift_definition plus_uint :: "uint \<Rightarrow> uint \<Rightarrow> uint" is "(+) :: dflt_size word \<Rightarrow> _" .
 lift_definition minus_uint :: "uint \<Rightarrow> uint \<Rightarrow> uint" is "(-)" .
 lift_definition uminus_uint :: "uint \<Rightarrow> uint" is uminus .
 lift_definition times_uint :: "uint \<Rightarrow> uint \<Rightarrow> uint" is "(*)" .
 instance by (standard; transfer) (simp_all add: algebra_simps)
 end
 
 instantiation uint :: semiring_modulo
 begin
 lift_definition divide_uint :: "uint \<Rightarrow> uint \<Rightarrow> uint" is "(div)" .
 lift_definition modulo_uint :: "uint \<Rightarrow> uint \<Rightarrow> uint" is "(mod)" .
 instance by (standard; transfer) (fact word_mod_div_equality)
 end
 
 instantiation uint :: linorder begin
 lift_definition less_uint :: "uint \<Rightarrow> uint \<Rightarrow> bool" is "(<)" .
 lift_definition less_eq_uint :: "uint \<Rightarrow> uint \<Rightarrow> bool" is "(\<le>)" .
 instance by (standard; transfer) (simp_all add: less_le_not_le linear)
 end
 
 lemmas [code] = less_uint.rep_eq less_eq_uint.rep_eq
 
 context
   includes lifting_syntax
   notes
     transfer_rule_of_bool [transfer_rule]
     transfer_rule_numeral [transfer_rule]
 begin
 
 lemma [transfer_rule]:
   "((=) ===> cr_uint) of_bool of_bool"
   by transfer_prover
 
 lemma transfer_rule_numeral_uint [transfer_rule]:
   "((=) ===> cr_uint) numeral numeral"
   by transfer_prover
 
 lemma [transfer_rule]:
   \<open>(cr_uint ===> (\<longleftrightarrow>)) even ((dvd) 2 :: uint \<Rightarrow> bool)\<close>
   by (unfold dvd_def) transfer_prover
 
 end
 
 instantiation uint :: semiring_bits
 begin
 
 lift_definition bit_uint :: \<open>uint \<Rightarrow> nat \<Rightarrow> bool\<close> is bit .
 
 instance
   by (standard; transfer)
     (fact bit_iff_odd even_iff_mod_2_eq_zero odd_iff_mod_2_eq_one odd_one bits_induct
        bits_div_0 bits_div_by_1 bits_mod_div_trivial even_succ_div_2
        even_mask_div_iff exp_div_exp_eq div_exp_eq mod_exp_eq mult_exp_mod_exp_eq
        div_exp_mod_exp_eq even_mult_exp_div_exp_iff)+
 
 end
 
 instantiation uint :: semiring_bit_shifts
 begin
 lift_definition push_bit_uint :: \<open>nat \<Rightarrow> uint \<Rightarrow> uint\<close> is push_bit .
 lift_definition drop_bit_uint :: \<open>nat \<Rightarrow> uint \<Rightarrow> uint\<close> is drop_bit .
 lift_definition take_bit_uint :: \<open>nat \<Rightarrow> uint \<Rightarrow> uint\<close> is take_bit .
 instance by (standard; transfer)
   (fact push_bit_eq_mult drop_bit_eq_div take_bit_eq_mod)+
 end
 
 instantiation uint :: ring_bit_operations
 begin
 lift_definition not_uint :: \<open>uint \<Rightarrow> uint\<close> is NOT .
 lift_definition and_uint :: \<open>uint \<Rightarrow> uint \<Rightarrow> uint\<close> is \<open>(AND)\<close> .
 lift_definition or_uint :: \<open>uint \<Rightarrow> uint \<Rightarrow> uint\<close> is \<open>(OR)\<close> .
 lift_definition xor_uint :: \<open>uint \<Rightarrow> uint \<Rightarrow> uint\<close> is \<open>(XOR)\<close> .
 lift_definition mask_uint :: \<open>nat \<Rightarrow> uint\<close> is mask .
 instance by (standard; transfer)
   (simp_all add: bit_and_iff bit_or_iff bit_xor_iff bit_not_iff minus_eq_not_minus_1 mask_eq_decr_exp)
 end
 
 lemma [code]:
   \<open>take_bit n a = a AND mask n\<close> for a :: uint
   by (fact take_bit_eq_mask)
 
 lemma [code]:
   \<open>mask (Suc n) = push_bit n (1 :: uint) OR mask n\<close>
   \<open>mask 0 = (0 :: uint)\<close>
   by (simp_all add: mask_Suc_exp push_bit_of_1)
 
 instantiation uint:: semiring_bit_syntax
 begin
 lift_definition test_bit_uint :: \<open>uint \<Rightarrow> nat \<Rightarrow> bool\<close> is test_bit .
 lift_definition shiftl_uint :: \<open>uint \<Rightarrow> nat \<Rightarrow> uint\<close> is shiftl .
 lift_definition shiftr_uint :: \<open>uint \<Rightarrow> nat \<Rightarrow> uint\<close> is shiftr .
 instance by (standard; transfer)
   (fact test_bit_eq_bit shiftl_word_eq shiftr_word_eq)+
 end
 
 instantiation uint :: lsb
 begin
 lift_definition lsb_uint :: \<open>uint \<Rightarrow> bool\<close> is lsb .
 instance by (standard; transfer)
   (fact lsb_odd)
 end
 
 instantiation uint :: msb
 begin
 lift_definition msb_uint :: \<open>uint \<Rightarrow> bool\<close> is msb .
 instance ..
 end
 
 instantiation uint :: set_bit
 begin
 lift_definition set_bit_uint :: \<open>uint \<Rightarrow> nat \<Rightarrow> bool \<Rightarrow> uint\<close> is set_bit .
 instance
   apply standard
   apply (unfold Bit_Operations.set_bit_def unset_bit_def)
   apply transfer
   apply (simp add: set_bit_eq Bit_Operations.set_bit_def unset_bit_def)
   done
 end
 
 instantiation uint :: bit_comprehension begin
 lift_definition set_bits_uint :: "(nat \<Rightarrow> bool) \<Rightarrow> uint" is "set_bits" .
 instance ..
 end
 
 lemmas [code] = test_bit_uint.rep_eq lsb_uint.rep_eq msb_uint.rep_eq
 
 instantiation uint :: equal begin
 lift_definition equal_uint :: "uint \<Rightarrow> uint \<Rightarrow> bool" is "equal_class.equal" .
 instance by standard (transfer, simp add: equal_eq)
 end
 
 lemmas [code] = equal_uint.rep_eq
 
 instantiation uint :: size begin
 lift_definition size_uint :: "uint \<Rightarrow> nat" is "size" .
 instance ..
 end
 
 lemmas [code] = size_uint.rep_eq
 
 lift_definition sshiftr_uint :: "uint \<Rightarrow> nat \<Rightarrow> uint" (infixl ">>>" 55) is sshiftr .
 
 lift_definition uint_of_int :: "int \<Rightarrow> uint" is "word_of_int" .
 
 text \<open>Use pretty numerals from integer for pretty printing\<close>
 
 context includes integer.lifting begin
 
 lift_definition Uint :: "integer \<Rightarrow> uint" is "word_of_int" .
 
 lemma Rep_uint_numeral [simp]: "Rep_uint (numeral n) = numeral n"
 by(induction n)(simp_all add: one_uint_def Abs_uint_inverse numeral.simps plus_uint_def)
 
 lemma numeral_uint_transfer [transfer_rule]:
   "(rel_fun (=) cr_uint) numeral numeral"
 by(auto simp add: cr_uint_def)
 
 lemma numeral_uint [code_unfold]: "numeral n = Uint (numeral n)"
 by transfer simp
 
 lemma Rep_uint_neg_numeral [simp]: "Rep_uint (- numeral n) = - numeral n"
 by(simp only: uminus_uint_def)(simp add: Abs_uint_inverse)
 
 lemma neg_numeral_uint [code_unfold]: "- numeral n = Uint (- numeral n)"
 by transfer(simp add: cr_uint_def)
 
 end
 
 lemma Abs_uint_numeral [code_post]: "Abs_uint (numeral n) = numeral n"
 by(induction n)(simp_all add: one_uint_def numeral.simps plus_uint_def Abs_uint_inverse)
 
 lemma Abs_uint_0 [code_post]: "Abs_uint 0 = 0"
 by(simp add: zero_uint_def)
 
 lemma Abs_uint_1 [code_post]: "Abs_uint 1 = 1"
 by(simp add: one_uint_def)
 
 section \<open>Code setup\<close>
 
 code_printing code_module Uint \<rightharpoonup> (SML)
 \<open>
 structure Uint : sig
   val set_bit : Word.word -> IntInf.int -> bool -> Word.word
   val shiftl : Word.word -> IntInf.int -> Word.word
   val shiftr : Word.word -> IntInf.int -> Word.word
   val shiftr_signed : Word.word -> IntInf.int -> Word.word
   val test_bit : Word.word -> IntInf.int -> bool
 end = struct
 
 fun set_bit x n b =
   let val mask = Word.<< (0wx1, Word.fromLargeInt (IntInf.toLarge n))
   in if b then Word.orb (x, mask)
      else Word.andb (x, Word.notb mask)
   end
 
 fun shiftl x n =
   Word.<< (x, Word.fromLargeInt (IntInf.toLarge n))
 
 fun shiftr x n =
   Word.>> (x, Word.fromLargeInt (IntInf.toLarge n))
 
 fun shiftr_signed x n =
   Word.~>> (x, Word.fromLargeInt (IntInf.toLarge n))
 
 fun test_bit x n =
   Word.andb (x, Word.<< (0wx1, Word.fromLargeInt (IntInf.toLarge n))) <> Word.fromInt 0
 
 end; (* struct Uint *)\<close>
 code_reserved SML Uint
 
 code_printing code_module Uint \<rightharpoonup> (Haskell)
  \<open>module Uint(Int, Word, dflt_size) where
 
   import qualified Prelude
   import Data.Int(Int)
   import Data.Word(Word)
   import qualified Data.Bits
 
   dflt_size :: Prelude.Integer
   dflt_size = Prelude.toInteger (bitSize_aux (0::Word)) where
     bitSize_aux :: (Data.Bits.Bits a, Prelude.Bounded a) => a -> Int
     bitSize_aux = Data.Bits.bitSize\<close>
   and (Haskell_Quickcheck)
  \<open>module Uint(Int, Word, dflt_size) where
 
   import qualified Prelude
   import Data.Int(Int)
   import Data.Word(Word)
   import qualified Data.Bits
 
   dflt_size :: Prelude.Int
   dflt_size = bitSize_aux (0::Word) where
     bitSize_aux :: (Data.Bits.Bits a, Prelude.Bounded a) => a -> Int
     bitSize_aux = Data.Bits.bitSize
 \<close>
 code_reserved Haskell Uint dflt_size
 
 text \<open>
   OCaml and Scala provide only signed bit numbers, so we use these and 
   implement sign-sensitive operations like comparisons manually.
 \<close>
 
 code_printing code_module "Uint" \<rightharpoonup> (OCaml)
 \<open>module Uint : sig
   type t = int
   val dflt_size : Z.t
   val less : t -> t -> bool
   val less_eq : t -> t -> bool
   val set_bit : t -> Z.t -> bool -> t
   val shiftl : t -> Z.t -> t
   val shiftr : t -> Z.t -> t
   val shiftr_signed : t -> Z.t -> t
   val test_bit : t -> Z.t -> bool
   val int_mask : int
   val int32_mask : int32
   val int64_mask : int64
 end = struct
 
 type t = int
 
 let dflt_size = Z.of_int Sys.int_size;;
 
 (* negative numbers have their highest bit set, 
    so they are greater than positive ones *)
 let less x y =
   if x<0 then
     y<0 && x<y
   else y < 0 || x < y;;
 
 let less_eq x y =
   if x < 0 then
     y < 0 &&  x <= y
   else y < 0 || x <= y;;
 
 let set_bit x n b =
   let mask = 1 lsl (Z.to_int n)
   in if b then x lor mask
      else x land (lnot mask);;
 
 let shiftl x n = x lsl (Z.to_int n);;
 
 let shiftr x n = x lsr (Z.to_int n);;
 
 let shiftr_signed x n = x asr (Z.to_int n);;
 
 let test_bit x n = x land (1 lsl (Z.to_int n)) <> 0;;
 
 let int_mask =
   if Sys.int_size < 32 then lnot 0 else 0xFFFFFFFF;;
 
 let int32_mask = 
   if Sys.int_size < 32 then Int32.pred (Int32.shift_left Int32.one Sys.int_size)
   else Int32.of_string "0xFFFFFFFF";;
 
 let int64_mask = 
   if Sys.int_size < 64 then Int64.pred (Int64.shift_left Int64.one Sys.int_size)
   else Int64.of_string "0xFFFFFFFFFFFFFFFF";;
 
 end;; (*struct Uint*)\<close>
 code_reserved OCaml Uint
 
 code_printing code_module Uint \<rightharpoonup> (Scala)
 \<open>object Uint {
 def dflt_size : BigInt = BigInt(32)
 
 def less(x: Int, y: Int) : Boolean =
   if (x < 0) y < 0 && x < y
   else y < 0 || x < y
 
 def less_eq(x: Int, y: Int) : Boolean =
   if (x < 0) y < 0 && x <= y
   else y < 0 || x <= y
 
 def set_bit(x: Int, n: BigInt, b: Boolean) : Int =
   if (b)
     x | (1 << n.intValue)
   else
     x & (1 << n.intValue).unary_~
 
 def shiftl(x: Int, n: BigInt) : Int = x << n.intValue
 
 def shiftr(x: Int, n: BigInt) : Int = x >>> n.intValue
 
 def shiftr_signed(x: Int, n: BigInt) : Int = x >> n.intValue
 
 def test_bit(x: Int, n: BigInt) : Boolean =
   (x & (1 << n.intValue)) != 0
 
 } /* object Uint */\<close>
 code_reserved Scala Uint
 
 
 text \<open>
   OCaml's conversion from Big\_int to int demands that the value fits into a signed integer.
   The following justifies the implementation.
 \<close>
 
 context includes integer.lifting begin
 definition wivs_mask :: int where "wivs_mask = 2^ dflt_size - 1"
 lift_definition wivs_mask_integer :: integer is wivs_mask .
 lemma [code]: "wivs_mask_integer = 2 ^ dflt_size - 1"
   by transfer (simp add: wivs_mask_def)
 
 definition wivs_shift :: int where "wivs_shift = 2 ^ dflt_size"
 lift_definition wivs_shift_integer :: integer is wivs_shift .
 lemma [code]: "wivs_shift_integer = 2 ^ dflt_size"
   by transfer (simp add: wivs_shift_def)
 
 definition wivs_index :: nat where "wivs_index == dflt_size - 1"
 lift_definition wivs_index_integer :: integer is "int wivs_index".
 lemma wivs_index_integer_code[code]: "wivs_index_integer = dflt_size_integer - 1"
   by transfer (simp add: wivs_index_def of_nat_diff)
 
 definition wivs_overflow :: int where "wivs_overflow == 2^ (dflt_size - 1)"
 lift_definition wivs_overflow_integer :: integer is wivs_overflow .
 lemma [code]: "wivs_overflow_integer = 2 ^ (dflt_size - 1)"
   by transfer (simp add: wivs_overflow_def)
 
 definition wivs_least :: int where "wivs_least == - wivs_overflow"
 lift_definition wivs_least_integer :: integer is wivs_least .
 lemma [code]: "wivs_least_integer = - (2 ^ (dflt_size - 1))"
   by transfer (simp add: wivs_overflow_def wivs_least_def)
 
 definition Uint_signed :: "integer \<Rightarrow> uint" where
   "Uint_signed i = (if i < wivs_least_integer \<or> wivs_overflow_integer \<le> i then undefined Uint i else Uint i)"
 
 lemma Uint_code [code]:
   "Uint i = 
   (let i' = i AND wivs_mask_integer in 
    if i' !! wivs_index then Uint_signed (i' - wivs_shift_integer) else Uint_signed i')"
   including undefined_transfer 
   unfolding Uint_signed_def
   apply transfer
   apply (rule word_of_int_via_signed)
   by (simp_all add: wivs_mask_def wivs_shift_def wivs_index_def wivs_overflow_def 
     wivs_least_def bin_mask_conv_pow2 shiftl_int_def)
 
 lemma Uint_signed_code [code abstract]:
   "Rep_uint (Uint_signed i) = 
   (if i < wivs_least_integer \<or> i \<ge> wivs_overflow_integer then Rep_uint (undefined Uint i) else word_of_int (int_of_integer_symbolic i))"
   unfolding Uint_signed_def Uint_def int_of_integer_symbolic_def word_of_integer_def
   by(simp add: Abs_uint_inverse)
 end
 
 text \<open>
   Avoid @{term Abs_uint} in generated code, use @{term Rep_uint'} instead. 
   The symbolic implementations for code\_simp use @{term Rep_uint}.
 
   The new destructor @{term Rep_uint'} is executable.
   As the simplifier is given the [code abstract] equations literally, 
   we cannot implement @{term Rep_uint} directly, because that makes code\_simp loop.
 
   If code generation raises Match, some equation probably contains @{term Rep_uint} 
   ([code abstract] equations for @{typ uint} may use @{term Rep_uint} because
   these instances will be folded away.)
 \<close>
 
 definition Rep_uint' where [simp]: "Rep_uint' = Rep_uint"
 
 lemma Rep_uint'_code [code]: "Rep_uint' x = (BITS n. x !! n)"
 unfolding Rep_uint'_def by transfer simp
 
 lift_definition Abs_uint' :: "dflt_size word \<Rightarrow> uint" is "\<lambda>x :: dflt_size word. x" .
 
 lemma Abs_uint'_code [code]:
   "Abs_uint' x = Uint (integer_of_int (uint x))"
 including integer.lifting by transfer simp
 
 declare [[code drop: "term_of_class.term_of :: uint \<Rightarrow> _"]]
 
 lemma term_of_uint_code [code]:
   defines "TR \<equiv> typerep.Typerep" and "bit0 \<equiv> STR ''Numeral_Type.bit0''" 
   shows
   "term_of_class.term_of x = 
    Code_Evaluation.App (Code_Evaluation.Const (STR ''Uint.uint.Abs_uint'') (TR (STR ''fun'') [TR (STR ''Word.word'')  [TR (STR ''Uint.dflt_size'') []], TR (STR ''Uint.uint'') []]))
        (term_of_class.term_of (Rep_uint' x))"
   by(simp add: term_of_anything)
 
 text \<open>Important:
   We must prevent the reflection oracle (eval-tac) to 
   use our machine-dependent type.
 \<close>
 
 code_printing
   type_constructor uint \<rightharpoonup>
   (SML) "Word.word" and
   (Haskell) "Uint.Word" and
   (OCaml) "Uint.t" and
   (Scala) "Int" and
   (Eval) "*** \"Error: Machine dependent type\" ***" and
   (Quickcheck) "Word.word" 
 | constant dflt_size_integer \<rightharpoonup>
   (SML) "(IntInf.fromLarge (Int.toLarge Word.wordSize))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.wordSize" and
   (Haskell) "Uint.dflt'_size" and
   (OCaml) "Uint.dflt'_size" and
   (Scala) "Uint.dflt'_size"
 | constant Uint \<rightharpoonup>
   (SML) "Word.fromLargeInt (IntInf.toLarge _)" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.fromInt" and
   (Haskell) "(Prelude.fromInteger _ :: Uint.Word)" and
   (Haskell_Quickcheck) "(Prelude.fromInteger (Prelude.toInteger _) :: Uint.Word)" and
   (Scala) "_.intValue"
 | constant Uint_signed \<rightharpoonup>
   (OCaml) "Z.to'_int"
 | constant "0 :: uint" \<rightharpoonup>
   (SML) "(Word.fromInt 0)" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "(Word.fromInt 0)" and
   (Haskell) "(0 :: Uint.Word)" and
   (OCaml) "0" and
   (Scala) "0"
 | constant "1 :: uint" \<rightharpoonup>
   (SML) "(Word.fromInt 1)" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "(Word.fromInt 1)" and
   (Haskell) "(1 :: Uint.Word)" and
   (OCaml) "1" and
   (Scala) "1"
 | constant "plus :: uint \<Rightarrow> _ " \<rightharpoonup>
   (SML) "Word.+ ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.+ ((_), (_))" and
   (Haskell) infixl 6 "+" and
   (OCaml) "Pervasives.(+)" and
   (Scala) infixl 7 "+"
 | constant "uminus :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.~" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.~" and
   (Haskell) "negate" and
   (OCaml) "Pervasives.(~-)" and
   (Scala) "!(- _)"
 | constant "minus :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.- ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.- ((_), (_))" and
   (Haskell) infixl 6 "-" and
   (OCaml) "Pervasives.(-)" and
   (Scala) infixl 7 "-"
 | constant "times :: uint \<Rightarrow> _ \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.* ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.* ((_), (_))" and
   (Haskell) infixl 7 "*" and
   (OCaml) "Pervasives.( * )" and
   (Scala) infixl 8 "*"
 | constant "HOL.equal :: uint \<Rightarrow> _ \<Rightarrow> bool" \<rightharpoonup>
   (SML) "!((_ : Word.word) = _)" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "!((_ : Word.word) = _)" and
   (Haskell) infix 4 "==" and
   (OCaml) "(Pervasives.(=):Uint.t -> Uint.t -> bool)" and
   (Scala) infixl 5 "=="
 | class_instance uint :: equal \<rightharpoonup>
   (Haskell) -
 | constant "less_eq :: uint \<Rightarrow> _ \<Rightarrow> bool" \<rightharpoonup>
   (SML) "Word.<= ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.<= ((_), (_))" and
   (Haskell) infix 4 "<=" and
   (OCaml) "Uint.less'_eq" and
   (Scala) "Uint.less'_eq"
 | constant "less :: uint \<Rightarrow> _ \<Rightarrow> bool" \<rightharpoonup>
   (SML) "Word.< ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.< ((_), (_))" and
   (Haskell) infix 4 "<" and
   (OCaml) "Uint.less" and
   (Scala) "Uint.less"
 | constant "NOT :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.notb" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.notb" and
   (Haskell) "Data'_Bits.complement" and
   (OCaml) "Pervasives.lnot" and
   (Scala) "_.unary'_~"
 | constant "(AND) :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.andb ((_),/ (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.andb ((_),/ (_))" and
   (Haskell) infixl 7 "Data_Bits..&." and
   (OCaml) "Pervasives.(land)" and
   (Scala) infixl 3 "&"
 | constant "(OR) :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.orb ((_),/ (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.orb ((_),/ (_))" and
   (Haskell) infixl 5 "Data_Bits..|." and
   (OCaml) "Pervasives.(lor)" and
   (Scala) infixl 1 "|"
 | constant "(XOR) :: uint \<Rightarrow> _" \<rightharpoonup>
   (SML) "Word.xorb ((_),/ (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.xorb ((_),/ (_))" and
   (Haskell) "Data'_Bits.xor" and
   (OCaml) "Pervasives.(lxor)" and
   (Scala) infixl 2 "^"
 
 definition uint_divmod :: "uint \<Rightarrow> uint \<Rightarrow> uint \<times> uint" where
   "uint_divmod x y = 
   (if y = 0 then (undefined ((div) :: uint \<Rightarrow> _) x (0 :: uint), undefined ((mod) :: uint \<Rightarrow> _) x (0 :: uint)) 
   else (x div y, x mod y))"
 
 definition uint_div :: "uint \<Rightarrow> uint \<Rightarrow> uint" 
 where "uint_div x y = fst (uint_divmod x y)"
 
 definition uint_mod :: "uint \<Rightarrow> uint \<Rightarrow> uint" 
 where "uint_mod x y = snd (uint_divmod x y)"
 
 lemma div_uint_code [code]: "x div y = (if y = 0 then 0 else uint_div x y)"
 including undefined_transfer unfolding uint_divmod_def uint_div_def
 by transfer(simp add: word_div_def)
 
 lemma mod_uint_code [code]: "x mod y = (if y = 0 then x else uint_mod x y)"
 including undefined_transfer unfolding uint_mod_def uint_divmod_def
 by transfer(simp add: word_mod_def)
 
 definition uint_sdiv :: "uint \<Rightarrow> uint \<Rightarrow> uint"
 where [code del]:
   "uint_sdiv x y =
    (if y = 0 then undefined ((div) :: uint \<Rightarrow> _) x (0 :: uint)
     else Abs_uint (Rep_uint x sdiv Rep_uint y))"
 
 definition div0_uint :: "uint \<Rightarrow> uint"
 where [code del]: "div0_uint x = undefined ((div) :: uint \<Rightarrow> _) x (0 :: uint)"
 declare [[code abort: div0_uint]]
 
 definition mod0_uint :: "uint \<Rightarrow> uint"
 where [code del]: "mod0_uint x = undefined ((mod) :: uint \<Rightarrow> _) x (0 :: uint)"
 declare [[code abort: mod0_uint]]
 
 definition wivs_overflow_uint :: uint 
   where "wivs_overflow_uint \<equiv> 1 << (dflt_size - 1)"
 
-(* TODO: Move to Word *)
-lemma dflt_size_word_pow_ne_zero [simp]:
-  "(2 :: 'a word) ^ (LENGTH('a::len) - Suc 0) \<noteq> 0"
-proof
-  assume "(2 :: 'a word) ^ (LENGTH('a::len) - Suc 0) = 0"
-  then have "unat ((2 :: 'a word) ^ (LENGTH('a::len) - Suc 0)) = unat 0"
-    by simp
-  then show False by (simp add: unat_p2)
-qed
-
 lemma uint_divmod_code [code]:
   "uint_divmod x y =
   (if wivs_overflow_uint \<le> y then if x < y then (0, x) else (1, x - y)
    else if y = 0 then (div0_uint x, mod0_uint x)
    else let q = (uint_sdiv (x >> 1) y) << 1;
             r = x - q * y
         in if r \<ge> y then (q + 1, r - y) else (q, r))"
   including undefined_transfer 
   unfolding uint_divmod_def uint_sdiv_def div0_uint_def mod0_uint_def
     wivs_overflow_uint_def
-  by transfer (simp add: divmod_via_sdivmod)
+  apply transfer
+  apply (simp add: divmod_via_sdivmod)
+  done
 
 lemma uint_sdiv_code [code abstract]:
   "Rep_uint (uint_sdiv x y) =
    (if y = 0 then Rep_uint (undefined ((div) :: uint \<Rightarrow> _) x (0 :: uint))
     else Rep_uint x sdiv Rep_uint y)"
 unfolding uint_sdiv_def by(simp add: Abs_uint_inverse)
 
 text \<open>
   Note that we only need a translation for signed division, but not for the remainder
   because @{thm uint_divmod_code} computes both with division only.
 \<close>
 
 code_printing
   constant uint_div \<rightharpoonup>
   (SML) "Word.div ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.div ((_), (_))" and
   (Haskell) "Prelude.div"
 | constant uint_mod \<rightharpoonup>
   (SML) "Word.mod ((_), (_))" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Word.mod ((_), (_))" and
   (Haskell) "Prelude.mod"
 | constant uint_divmod \<rightharpoonup>
   (Haskell) "divmod"
 | constant uint_sdiv \<rightharpoonup>
   (OCaml) "Pervasives.('/)" and
   (Scala) "_ '/ _"
 
 definition uint_test_bit :: "uint \<Rightarrow> integer \<Rightarrow> bool"
 where [code del]:
   "uint_test_bit x n =
   (if n < 0 \<or> dflt_size_integer \<le> n then undefined (test_bit :: uint \<Rightarrow> _) x n
    else x !! (nat_of_integer n))"
 
 lemma test_bit_eq_bit_uint [code]:
   \<open>test_bit = (bit :: uint \<Rightarrow> _)\<close>
   by (rule ext)+ (transfer, transfer, simp)
 
 lemma test_bit_uint_code [code]:
   "test_bit x n \<longleftrightarrow> n < dflt_size \<and> uint_test_bit x (integer_of_nat n)"
   including undefined_transfer integer.lifting unfolding uint_test_bit_def
   by (transfer, simp, transfer, simp)
 
 lemma uint_test_bit_code [code]:
   "uint_test_bit w n =
   (if n < 0 \<or> dflt_size_integer \<le> n then undefined (test_bit :: uint \<Rightarrow> _) w n else Rep_uint w !! nat_of_integer n)"
 unfolding uint_test_bit_def
 by(simp add: test_bit_uint.rep_eq)
 
 code_printing constant uint_test_bit \<rightharpoonup>
   (SML) "Uint.test'_bit" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Uint.test'_bit" and
   (Haskell) "Data'_Bits.testBitBounded" and
   (OCaml) "Uint.test'_bit" and
   (Scala) "Uint.test'_bit"
 
 definition uint_set_bit :: "uint \<Rightarrow> integer \<Rightarrow> bool \<Rightarrow> uint"
 where [code del]:
   "uint_set_bit x n b =
   (if n < 0 \<or> dflt_size_integer \<le> n then undefined (set_bit :: uint \<Rightarrow> _) x n b
    else set_bit x (nat_of_integer n) b)"
 
 lemma set_bit_uint_code [code]:
   "set_bit x n b = (if n < dflt_size then uint_set_bit x (integer_of_nat n) b else x)"
   including undefined_transfer integer.lifting unfolding uint_set_bit_def
   by (transfer) (auto cong: conj_cong simp add: not_less set_bit_beyond word_size)
 
 lemma uint_set_bit_code [code abstract]:
   "Rep_uint (uint_set_bit w n b) = 
   (if n < 0 \<or> dflt_size_integer \<le> n then Rep_uint (undefined (set_bit :: uint \<Rightarrow> _) w n b)
    else set_bit (Rep_uint w) (nat_of_integer n) b)"
 including undefined_transfer integer.lifting unfolding uint_set_bit_def by transfer simp
 
 code_printing constant uint_set_bit \<rightharpoonup>
   (SML) "Uint.set'_bit" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Uint.set'_bit" and
   (Haskell) "Data'_Bits.setBitBounded" and
   (OCaml) "Uint.set'_bit" and
   (Scala) "Uint.set'_bit"
 
 lift_definition uint_set_bits :: "(nat \<Rightarrow> bool) \<Rightarrow> uint \<Rightarrow> nat \<Rightarrow> uint" is set_bits_aux .
 
 lemma uint_set_bits_code [code]:
   "uint_set_bits f w n =
   (if n = 0 then w 
    else let n' = n - 1 in uint_set_bits f ((w << 1) OR (if f n' then 1 else 0)) n')"
 by(transfer fixing: n)(cases n, simp_all)
 
 lemma set_bits_uint [code]:
   "(BITS n. f n) = uint_set_bits f 0 dflt_size"
   by transfer (simp add: set_bits_conv_set_bits_aux)
 
 lemma lsb_code [code]: fixes x :: uint shows "lsb x = x !! 0"
 by transfer(simp add: word_lsb_def word_test_bit_def)
 
 definition uint_shiftl :: "uint \<Rightarrow> integer \<Rightarrow> uint"
 where [code del]:
   "uint_shiftl x n = (if n < 0 \<or> dflt_size_integer \<le> n then undefined (shiftl :: uint \<Rightarrow> _) x n else x << (nat_of_integer n))"
 
 lemma shiftl_uint_code [code]: "x << n = (if n < dflt_size then uint_shiftl x (integer_of_nat n) else 0)"
 including undefined_transfer integer.lifting unfolding uint_shiftl_def
 by transfer(simp add: not_less shiftl_zero_size word_size)
 
 lemma uint_shiftl_code [code abstract]:
   "Rep_uint (uint_shiftl w n) =
   (if n < 0 \<or> dflt_size_integer \<le> n then Rep_uint (undefined (shiftl :: uint \<Rightarrow> _) w n) else Rep_uint w << (nat_of_integer n))"
 including undefined_transfer integer.lifting unfolding uint_shiftl_def by transfer simp
 
 code_printing constant uint_shiftl \<rightharpoonup>
   (SML) "Uint.shiftl" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Uint.shiftl" and
   (Haskell) "Data'_Bits.shiftlBounded" and
   (OCaml) "Uint.shiftl" and
   (Scala) "Uint.shiftl"
 
 definition uint_shiftr :: "uint \<Rightarrow> integer \<Rightarrow> uint"
 where [code del]:
   "uint_shiftr x n = (if n < 0 \<or> dflt_size_integer \<le> n then undefined (shiftr :: uint \<Rightarrow> _) x n else x >> (nat_of_integer n))"
 
 lemma shiftr_uint_code [code]: "x >> n = (if n < dflt_size then uint_shiftr x (integer_of_nat n) else 0)"
 including undefined_transfer integer.lifting unfolding uint_shiftr_def
 by transfer(simp add: not_less shiftr_zero_size word_size)
 
 lemma uint_shiftr_code [code abstract]:
   "Rep_uint (uint_shiftr w n) =
   (if n < 0 \<or> dflt_size_integer \<le> n then Rep_uint (undefined (shiftr :: uint \<Rightarrow> _) w n) else Rep_uint w >> nat_of_integer n)"
 including undefined_transfer unfolding uint_shiftr_def by transfer simp
 
 code_printing constant uint_shiftr \<rightharpoonup>
   (SML) "Uint.shiftr" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Uint.shiftr" and
   (Haskell) "Data'_Bits.shiftrBounded" and
   (OCaml) "Uint.shiftr" and
   (Scala) "Uint.shiftr"
 
 definition uint_sshiftr :: "uint \<Rightarrow> integer \<Rightarrow> uint"
 where [code del]:
   "uint_sshiftr x n =
   (if n < 0 \<or> dflt_size_integer \<le> n then undefined sshiftr_uint x n else sshiftr_uint x (nat_of_integer n))"
 
 lemma sshiftr_beyond: fixes x :: "'a :: len word" shows
   "size x \<le> n \<Longrightarrow> x >>> n = (if x !! (size x - 1) then -1 else 0)"
 by(rule word_eqI)(simp add: nth_sshiftr word_size)
 
 lemma sshiftr_uint_code [code]:
   "x >>> n = 
   (if n < dflt_size then uint_sshiftr x (integer_of_nat n) else 
     if x !! wivs_index then -1 else 0)"
 including undefined_transfer integer.lifting unfolding uint_sshiftr_def
 by transfer(simp add: not_less sshiftr_beyond word_size wivs_index_def)
 
 lemma uint_sshiftr_code [code abstract]:
   "Rep_uint (uint_sshiftr w n) =
   (if n < 0 \<or> dflt_size_integer \<le> n then Rep_uint (undefined sshiftr_uint w n) else Rep_uint w >>> (nat_of_integer n))"
 including undefined_transfer unfolding uint_sshiftr_def by transfer simp
 
 code_printing constant uint_sshiftr \<rightharpoonup>
   (SML) "Uint.shiftr'_signed" and
   (Eval) "(raise (Fail \"Machine dependent code\"))" and
   (Quickcheck) "Uint.shiftr'_signed" and
   (Haskell) 
     "(Prelude.fromInteger (Prelude.toInteger (Data'_Bits.shiftrBounded (Prelude.fromInteger (Prelude.toInteger _) :: Uint.Int) _)) :: Uint.Word)" and
   (OCaml) "Uint.shiftr'_signed" and
   (Scala) "Uint.shiftr'_signed"
 
 lemma uint_msb_test_bit: "msb x \<longleftrightarrow> (x :: uint) !! wivs_index"
 by transfer(simp add: msb_nth wivs_index_def)
 
 lemma msb_uint_code [code]: "msb x \<longleftrightarrow> uint_test_bit x wivs_index_integer"
   apply(simp add: uint_test_bit_def uint_msb_test_bit 
   wivs_index_integer_code dflt_size_integer_def wivs_index_def)
   by (metis (full_types) One_nat_def dflt_size(2) less_iff_diff_less_0 
     nat_of_integer_of_nat of_nat_1 of_nat_diff of_nat_less_0_iff wivs_index_def)
 
 lemma uint_of_int_code [code]: "uint_of_int i = (BITS n. i !! n)"
 by transfer(simp add: word_of_int_conv_set_bits test_bit_int_def[abs_def])
 
 section \<open>Quickcheck setup\<close>
 
 definition uint_of_natural :: "natural \<Rightarrow> uint"
 where "uint_of_natural x \<equiv> Uint (integer_of_natural x)"
 
 instantiation uint :: "{random, exhaustive, full_exhaustive}" begin
 definition "random_uint \<equiv> qc_random_cnv uint_of_natural"
 definition "exhaustive_uint \<equiv> qc_exhaustive_cnv uint_of_natural"
 definition "full_exhaustive_uint \<equiv> qc_full_exhaustive_cnv uint_of_natural"
 instance ..
 end
 
 instantiation uint :: narrowing begin
 
 interpretation quickcheck_narrowing_samples
   "\<lambda>i. (Uint i, Uint (- i))" "0"
   "Typerep.Typerep (STR ''Uint.uint'') []" .
 
 definition "narrowing_uint d = qc_narrowing_drawn_from (narrowing_samples d) d"
 declare [[code drop: "partial_term_of :: uint itself \<Rightarrow> _"]]
 lemmas partial_term_of_uint [code] = partial_term_of_code
 
 instance ..
 end
 
 no_notation sshiftr_uint (infixl ">>>" 55)
 
 end
diff --git a/thys/Word_Lib/Word_Lemmas.thy b/thys/Word_Lib/Word_Lemmas.thy
--- a/thys/Word_Lib/Word_Lemmas.thy
+++ b/thys/Word_Lib/Word_Lemmas.thy
@@ -1,6157 +1,6159 @@
 (*
  * Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 section "Lemmas with Generic Word Length"
 
 theory Word_Lemmas
   imports
     "HOL-Word.Misc_lsb"
     Word_EqI
     Word_Enum
     "HOL-Library.Sublist"
 begin
 
 lemmas is_aligned_def = is_aligned_iff_dvd_nat
 
 lemma word_plus_mono_left:
   fixes x :: "'a :: len word"
   shows "\<lbrakk>y \<le> z; x \<le> x + z\<rbrakk> \<Longrightarrow> y + x \<le> z + x"
   by unat_arith
 
 lemma word_shiftl_add_distrib:
   fixes x :: "'a :: len word"
   shows "(x + y) << n = (x << n) + (y << n)"
   by (simp add: shiftl_t2n ring_distribs)
 
 lemma less_Suc_unat_less_bound:
   "n < Suc (unat (x :: 'a :: len word)) \<Longrightarrow> n < 2 ^ LENGTH('a)"
   by (auto elim!: order_less_le_trans intro: Suc_leI)
 
 lemma up_ucast_inj:
   "\<lbrakk> ucast x = (ucast y::'b::len word); LENGTH('a) \<le> len_of TYPE ('b) \<rbrakk> \<Longrightarrow> x = (y::'a::len word)"
   by (subst (asm) bang_eq) (fastforce simp: nth_ucast word_size intro: word_eqI)
 
 lemmas ucast_up_inj = up_ucast_inj
 
 lemma up_ucast_inj_eq:
   "LENGTH('a) \<le> len_of TYPE ('b) \<Longrightarrow> (ucast x = (ucast y::'b::len word)) = (x = (y::'a::len word))"
   by (fastforce dest: up_ucast_inj)
 
 lemma no_plus_overflow_neg:
   "(x :: 'a :: len word) < -y \<Longrightarrow> x \<le> x + y"
   by (metis diff_minus_eq_add less_imp_le sub_wrap_lt)
 
 lemma ucast_ucast_eq:
   "\<lbrakk> ucast x = (ucast (ucast y::'a word)::'c::len word); LENGTH('a) \<le> LENGTH('b);
      LENGTH('b) \<le> LENGTH('c) \<rbrakk> \<Longrightarrow>
    x = ucast y" for x :: "'a::len word" and y :: "'b::len word"
   by (fastforce intro: word_eqI simp: bang_eq nth_ucast word_size)
 
 lemma ucast_0_I:
   "x = 0 \<Longrightarrow> ucast x = 0"
   by simp
 
 text \<open>right-padding a word to a certain length\<close>
 
 definition
   "bl_pad_to bl sz \<equiv> bl @ (replicate (sz - length bl) False)"
 
 lemma bl_pad_to_length:
   assumes lbl: "length bl \<le> sz"
   shows   "length (bl_pad_to bl sz) = sz"
   using lbl by (simp add: bl_pad_to_def)
 
 lemma bl_pad_to_prefix:
   "prefix bl (bl_pad_to bl sz)"
   by (simp add: bl_pad_to_def)
 
 lemma same_length_is_parallel:
   assumes len: "\<forall>y \<in> set as. length y = x"
   shows  "\<forall>x \<in> set as. \<forall>y \<in> set as - {x}. x \<parallel> y"
 proof (rule, rule)
   fix x y
   assume xi: "x \<in> set as" and yi: "y \<in> set as - {x}"
   from len obtain q where len': "\<forall>y \<in> set as. length y = q" ..
 
   show "x \<parallel> y"
   proof (rule not_equal_is_parallel)
     from xi yi show "x \<noteq> y" by auto
     from xi yi len' show "length x = length y" by (auto dest: bspec)
   qed
 qed
 
 text \<open>Lemmas about words\<close>
 
 lemmas and_bang = word_and_nth
 
 lemma of_drop_to_bl:
   "of_bl (drop n (to_bl x)) = (x && mask (size x - n))"
   by (simp add: of_bl_drop word_size_bl)
 
 lemma word_add_offset_less:
   fixes x :: "'a :: len word"
   assumes yv: "y < 2 ^ n"
   and     xv: "x < 2 ^ m"
   and     mnv: "sz < LENGTH('a :: len)"
   and    xv': "x < 2 ^ (LENGTH('a :: len) - n)"
   and     mn: "sz = m + n"
   shows   "x * 2 ^ n + y < 2 ^ sz"
 proof (subst mn)
   from mnv mn have nv: "n < LENGTH('a)" and mv: "m < LENGTH('a)"  by auto
 
   have uy: "unat y < 2 ^ n"
     by (rule order_less_le_trans [OF unat_mono [OF yv] order_eq_refl],
         rule unat_power_lower[OF nv])
 
   have ux: "unat x < 2 ^ m"
     by (rule order_less_le_trans [OF unat_mono [OF xv] order_eq_refl],
         rule unat_power_lower[OF mv])
 
   then show "x * 2 ^ n + y < 2 ^ (m + n)" using ux uy nv mnv xv'
     apply (subst word_less_nat_alt)
     apply (subst unat_word_ariths)+
     apply (subst mod_less)
      apply simp
      apply (subst mult.commute)
      apply (rule nat_less_power_trans [OF _ order_less_imp_le [OF nv]])
      apply (rule order_less_le_trans [OF unat_mono [OF xv']])
      apply (cases "n = 0"; simp)
     apply (subst unat_power_lower[OF nv])
     apply (subst mod_less)
      apply (erule order_less_le_trans [OF nat_add_offset_less], assumption)
       apply (rule mn)
      apply simp
     apply (simp add: mn mnv)
     apply (erule nat_add_offset_less; simp)
     done
 qed
 
 lemma word_less_power_trans:
   fixes n :: "'a :: len word"
   assumes nv: "n < 2 ^ (m - k)"
   and     kv: "k \<le> m"
   and     mv: "m < len_of TYPE ('a)"
   shows "2 ^ k * n < 2 ^ m"
   using nv kv mv
   apply -
   apply (subst word_less_nat_alt)
   apply (subst unat_word_ariths)
   apply (subst mod_less)
    apply simp
    apply (rule nat_less_power_trans)
     apply (erule order_less_trans [OF unat_mono])
     apply simp
    apply simp
   apply simp
   apply (rule nat_less_power_trans)
    apply (subst unat_power_lower[where 'a = 'a, symmetric])
     apply simp
    apply (erule unat_mono)
   apply simp
   done
 
 lemma Suc_unat_diff_1:
   fixes x :: "'a :: len word"
   assumes lt: "1 \<le> x"
   shows "Suc (unat (x - 1)) = unat x"
 proof -
   have "0 < unat x"
     by (rule order_less_le_trans [where y = 1], simp, subst unat_1 [symmetric],
         rule iffD1 [OF word_le_nat_alt lt])
 
   then show ?thesis
     by ((subst unat_sub [OF lt])+, simp only:  unat_1)
 qed
 
 lemma word_div_sub:
   fixes x :: "'a :: len word"
   assumes yx: "y \<le> x"
   and     y0: "0 < y"
   shows "(x - y) div y = x div y - 1"
   apply (rule word_unat.Rep_eqD)
   apply (subst unat_div)
   apply (subst unat_sub [OF yx])
   apply (subst unat_sub)
    apply (subst word_le_nat_alt)
    apply (subst unat_div)
    apply (subst le_div_geq)
      apply (rule order_le_less_trans [OF _ unat_mono [OF y0]])
      apply simp
     apply (subst word_le_nat_alt [symmetric], rule yx)
    apply simp
   apply (subst unat_div)
   apply (subst le_div_geq [OF _ iffD1 [OF word_le_nat_alt yx]])
    apply (rule order_le_less_trans [OF _ unat_mono [OF y0]])
    apply simp
   apply simp
   done
 
 lemma word_mult_less_mono1:
   fixes i :: "'a :: len word"
   assumes ij: "i < j"
   and    knz: "0 < k"
   and    ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows  "i * k < j * k"
 proof -
   from ij ujk knz have jk: "unat i * unat k < 2 ^ len_of TYPE ('a)"
     by (auto intro: order_less_subst2 simp: word_less_nat_alt elim: mult_less_mono1)
 
   then show ?thesis using ujk knz ij
     by (auto simp: word_less_nat_alt iffD1 [OF unat_mult_lem])
 qed
 
 lemma word_mult_less_dest:
   fixes i :: "'a :: len word"
   assumes ij: "i * k < j * k"
   and    uik: "unat i * unat k < 2 ^ len_of TYPE ('a)"
   and    ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows  "i < j"
   using uik ujk ij
   by (auto simp: word_less_nat_alt iffD1 [OF unat_mult_lem] elim: mult_less_mono1)
 
 lemma word_mult_less_cancel:
   fixes k :: "'a :: len word"
   assumes knz: "0 < k"
   and    uik: "unat i * unat k < 2 ^ len_of TYPE ('a)"
   and    ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows "(i * k < j * k) = (i < j)"
   by (rule iffI [OF word_mult_less_dest [OF _ uik ujk] word_mult_less_mono1 [OF _ knz ujk]])
 
 lemma Suc_div_unat_helper:
   assumes szv: "sz < LENGTH('a :: len)"
   and   usszv: "us \<le> sz"
   shows "2 ^ (sz - us) = Suc (unat (((2::'a :: len word) ^ sz - 1) div 2 ^ us))"
 proof -
   note usv = order_le_less_trans [OF usszv szv]
 
   from usszv obtain q where qv: "sz = us + q" by (auto simp: le_iff_add)
 
   have "Suc (unat (((2:: 'a word) ^ sz - 1) div 2 ^ us)) =
     (2 ^ us + unat ((2:: 'a word) ^ sz - 1)) div 2 ^ us"
     apply (subst unat_div unat_power_lower[OF usv])+
     apply (subst div_add_self1, simp+)
     done
 
   also have "\<dots> = ((2 ^ us - 1) + 2 ^ sz) div 2 ^ us" using szv
     by (simp add: unat_minus_one)
 
   also have "\<dots> = 2 ^ q + ((2 ^ us - 1) div 2 ^ us)"
     apply (subst qv)
     apply (subst power_add)
     apply (subst div_mult_self2; simp)
     done
 
   also have "\<dots> = 2 ^ (sz - us)" using qv by simp
 
   finally show ?thesis ..
 qed
 
 
 lemma set_enum_word8_def:
   "(set enum::word8 set) = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
                             20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,
                             37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
                             54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70,
                             71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87,
                             88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103,
                             104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
                             118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131,
                             132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145,
                             146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
                             160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,
                             174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187,
                             188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201,
                             202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215,
                             216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,
                             230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243,
                             244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255}"
   by eval
 
 lemma set_strip_insert: "\<lbrakk> x \<in> insert a S; x \<noteq> a \<rbrakk> \<Longrightarrow> x \<in> S"
   by simp
 
 lemma word8_exhaust:
   fixes x :: word8
   shows "\<lbrakk>x \<noteq> 0; x \<noteq> 1; x \<noteq> 2; x \<noteq> 3; x \<noteq> 4; x \<noteq> 5; x \<noteq> 6; x \<noteq> 7; x \<noteq> 8; x \<noteq> 9; x \<noteq> 10; x \<noteq> 11; x \<noteq>
           12; x \<noteq> 13; x \<noteq> 14; x \<noteq> 15; x \<noteq> 16; x \<noteq> 17; x \<noteq> 18; x \<noteq> 19; x \<noteq> 20; x \<noteq> 21; x \<noteq> 22; x \<noteq>
           23; x \<noteq> 24; x \<noteq> 25; x \<noteq> 26; x \<noteq> 27; x \<noteq> 28; x \<noteq> 29; x \<noteq> 30; x \<noteq> 31; x \<noteq> 32; x \<noteq> 33; x \<noteq>
           34; x \<noteq> 35; x \<noteq> 36; x \<noteq> 37; x \<noteq> 38; x \<noteq> 39; x \<noteq> 40; x \<noteq> 41; x \<noteq> 42; x \<noteq> 43; x \<noteq> 44; x \<noteq>
           45; x \<noteq> 46; x \<noteq> 47; x \<noteq> 48; x \<noteq> 49; x \<noteq> 50; x \<noteq> 51; x \<noteq> 52; x \<noteq> 53; x \<noteq> 54; x \<noteq> 55; x \<noteq>
           56; x \<noteq> 57; x \<noteq> 58; x \<noteq> 59; x \<noteq> 60; x \<noteq> 61; x \<noteq> 62; x \<noteq> 63; x \<noteq> 64; x \<noteq> 65; x \<noteq> 66; x \<noteq>
           67; x \<noteq> 68; x \<noteq> 69; x \<noteq> 70; x \<noteq> 71; x \<noteq> 72; x \<noteq> 73; x \<noteq> 74; x \<noteq> 75; x \<noteq> 76; x \<noteq> 77; x \<noteq>
           78; x \<noteq> 79; x \<noteq> 80; x \<noteq> 81; x \<noteq> 82; x \<noteq> 83; x \<noteq> 84; x \<noteq> 85; x \<noteq> 86; x \<noteq> 87; x \<noteq> 88; x \<noteq>
           89; x \<noteq> 90; x \<noteq> 91; x \<noteq> 92; x \<noteq> 93; x \<noteq> 94; x \<noteq> 95; x \<noteq> 96; x \<noteq> 97; x \<noteq> 98; x \<noteq> 99; x \<noteq>
           100; x \<noteq> 101; x \<noteq> 102; x \<noteq> 103; x \<noteq> 104; x \<noteq> 105; x \<noteq> 106; x \<noteq> 107; x \<noteq> 108; x \<noteq> 109; x \<noteq>
           110; x \<noteq> 111; x \<noteq> 112; x \<noteq> 113; x \<noteq> 114; x \<noteq> 115; x \<noteq> 116; x \<noteq> 117; x \<noteq> 118; x \<noteq> 119; x \<noteq>
           120; x \<noteq> 121; x \<noteq> 122; x \<noteq> 123; x \<noteq> 124; x \<noteq> 125; x \<noteq> 126; x \<noteq> 127; x \<noteq> 128; x \<noteq> 129; x \<noteq>
           130; x \<noteq> 131; x \<noteq> 132; x \<noteq> 133; x \<noteq> 134; x \<noteq> 135; x \<noteq> 136; x \<noteq> 137; x \<noteq> 138; x \<noteq> 139; x \<noteq>
           140; x \<noteq> 141; x \<noteq> 142; x \<noteq> 143; x \<noteq> 144; x \<noteq> 145; x \<noteq> 146; x \<noteq> 147; x \<noteq> 148; x \<noteq> 149; x \<noteq>
           150; x \<noteq> 151; x \<noteq> 152; x \<noteq> 153; x \<noteq> 154; x \<noteq> 155; x \<noteq> 156; x \<noteq> 157; x \<noteq> 158; x \<noteq> 159; x \<noteq>
           160; x \<noteq> 161; x \<noteq> 162; x \<noteq> 163; x \<noteq> 164; x \<noteq> 165; x \<noteq> 166; x \<noteq> 167; x \<noteq> 168; x \<noteq> 169; x \<noteq>
           170; x \<noteq> 171; x \<noteq> 172; x \<noteq> 173; x \<noteq> 174; x \<noteq> 175; x \<noteq> 176; x \<noteq> 177; x \<noteq> 178; x \<noteq> 179; x \<noteq>
           180; x \<noteq> 181; x \<noteq> 182; x \<noteq> 183; x \<noteq> 184; x \<noteq> 185; x \<noteq> 186; x \<noteq> 187; x \<noteq> 188; x \<noteq> 189; x \<noteq>
           190; x \<noteq> 191; x \<noteq> 192; x \<noteq> 193; x \<noteq> 194; x \<noteq> 195; x \<noteq> 196; x \<noteq> 197; x \<noteq> 198; x \<noteq> 199; x \<noteq>
           200; x \<noteq> 201; x \<noteq> 202; x \<noteq> 203; x \<noteq> 204; x \<noteq> 205; x \<noteq> 206; x \<noteq> 207; x \<noteq> 208; x \<noteq> 209; x \<noteq>
           210; x \<noteq> 211; x \<noteq> 212; x \<noteq> 213; x \<noteq> 214; x \<noteq> 215; x \<noteq> 216; x \<noteq> 217; x \<noteq> 218; x \<noteq> 219; x \<noteq>
           220; x \<noteq> 221; x \<noteq> 222; x \<noteq> 223; x \<noteq> 224; x \<noteq> 225; x \<noteq> 226; x \<noteq> 227; x \<noteq> 228; x \<noteq> 229; x \<noteq>
           230; x \<noteq> 231; x \<noteq> 232; x \<noteq> 233; x \<noteq> 234; x \<noteq> 235; x \<noteq> 236; x \<noteq> 237; x \<noteq> 238; x \<noteq> 239; x \<noteq>
           240; x \<noteq> 241; x \<noteq> 242; x \<noteq> 243; x \<noteq> 244; x \<noteq> 245; x \<noteq> 246; x \<noteq> 247; x \<noteq> 248; x \<noteq> 249; x \<noteq>
           250; x \<noteq> 251; x \<noteq> 252; x \<noteq> 253; x \<noteq> 254; x \<noteq> 255\<rbrakk> \<Longrightarrow> P"
   apply (subgoal_tac "x \<in> set enum", subst (asm) set_enum_word8_def)
     apply (drule set_strip_insert, assumption)+
    apply (erule emptyE)
   apply (subst enum_UNIV, rule UNIV_I)
   done
 
 lemma upto_enum_red':
   assumes lt: "1 \<le> X"
   shows "[(0::'a :: len word) .e. X - 1] =  map of_nat [0 ..< unat X]"
 proof -
   have lt': "unat X < 2 ^ LENGTH('a)"
     by (rule unat_lt2p)
 
   show ?thesis
     apply (subst upto_enum_red)
     apply (simp del: upt.simps)
     apply (subst Suc_unat_diff_1 [OF lt])
     apply (rule map_cong [OF refl])
     apply (rule toEnum_of_nat)
     apply simp
     apply (erule order_less_trans [OF _ lt'])
     done
 qed
 
 lemma upto_enum_red2:
   assumes szv: "sz < LENGTH('a :: len)"
   shows "[(0:: 'a :: len word) .e. 2 ^ sz - 1] =
   map of_nat [0 ..< 2 ^ sz]" using szv
   apply (subst unat_power_lower[OF szv, symmetric])
   apply (rule upto_enum_red')
   apply (subst word_le_nat_alt, simp)
   done
 
 lemma upto_enum_step_red:
   assumes szv: "sz < LENGTH('a)"
   and   usszv: "us \<le> sz"
   shows "[0 :: 'a :: len word , 2 ^ us .e. 2 ^ sz - 1] =
   map (\<lambda>x. of_nat x * 2 ^ us) [0 ..< 2 ^ (sz - us)]" using szv
   unfolding upto_enum_step_def
   apply (subst if_not_P)
    apply (rule leD)
    apply (subst word_le_nat_alt)
    apply (subst unat_minus_one)
     apply simp
    apply simp
   apply simp
   apply (subst upto_enum_red)
   apply (simp del: upt.simps)
   apply (subst Suc_div_unat_helper [where 'a = 'a, OF szv usszv, symmetric])
   apply clarsimp
   apply (subst toEnum_of_nat)
    apply (erule order_less_trans)
    using szv
    apply simp
   apply simp
   done
 
 lemma upto_enum_word:
   "[x .e. y] = map of_nat [unat x ..< Suc (unat y)]"
   apply (subst upto_enum_red)
   apply clarsimp
   apply (subst toEnum_of_nat)
    prefer 2
    apply (rule refl)
   apply (erule disjE, simp)
   apply clarsimp
   apply (erule order_less_trans)
   apply simp
   done
 
 lemma word_upto_Cons_eq:
   "x < y \<Longrightarrow> [x::'a::len word .e. y] = x # [x + 1 .e. y]"
   apply (subst upto_enum_red)
   apply (subst upt_conv_Cons, unat_arith)
   apply (simp only: list.map list.inject upto_enum_red to_from_enum simp_thms)
   apply (rule map_cong[OF _ refl])
   apply (rule arg_cong2[where f = "\<lambda>x y. [x ..< y]"], unat_arith)
   apply (rule refl)
   done
 
 lemma distinct_enum_upto:
   "distinct [(0 :: 'a::len word) .e. b]"
 proof -
   have "\<And>(b::'a word). [0 .e. b] = nths enum {..< Suc (fromEnum b)}"
     apply (subst upto_enum_red)
     apply (subst nths_upt_eq_take)
     apply (subst enum_word_def)
     apply (subst take_map)
     apply (subst take_upt)
      apply (simp only: add_0 fromEnum_unat)
      apply (rule order_trans [OF _ order_eq_refl])
       apply (rule Suc_leI [OF unat_lt2p])
      apply simp
     apply clarsimp
     apply (rule toEnum_of_nat)
     apply (erule order_less_trans [OF _ unat_lt2p])
     done
 
   then show ?thesis
     by (rule ssubst) (rule distinct_nthsI, simp)
 qed
 
 lemma upto_enum_set_conv [simp]:
   fixes a :: "'a :: len word"
   shows "set [a .e. b] = {x. a \<le> x \<and> x \<le> b}"
   apply (subst upto_enum_red)
   apply (subst set_map)
   apply safe
     apply simp
     apply clarsimp
     apply (erule disjE)
      apply simp
      apply (erule iffD2 [OF word_le_nat_alt])
     apply clarsimp
     apply (erule word_unat.Rep_cases [OF unat_le [OF order_less_imp_le]])
     apply simp
     apply (erule iffD2 [OF word_le_nat_alt])
    apply simp
 
    apply clarsimp
    apply (erule disjE)
     apply simp
    apply clarsimp
    apply (rule word_unat.Rep_cases [OF unat_le  [OF order_less_imp_le]])
     apply assumption
    apply simp
    apply (erule order_less_imp_le [OF iffD2 [OF word_less_nat_alt]])
   apply clarsimp
   apply (rule_tac x="fromEnum x" in image_eqI)
    apply clarsimp
   apply clarsimp
   apply (rule conjI)
    apply (subst word_le_nat_alt [symmetric])
    apply simp
   apply safe
    apply (simp add: word_le_nat_alt [symmetric])
   apply (simp add: word_less_nat_alt [symmetric])
   done
 
 lemma upto_enum_less:
   assumes xin: "x \<in> set [(a::'a::len word).e.2 ^ n - 1]"
   and     nv:  "n < LENGTH('a::len)"
   shows   "x < 2 ^ n"
 proof (cases n)
   case 0
   then show ?thesis using xin by simp
 next
   case (Suc m)
   show ?thesis using xin nv by simp
 qed
 
 lemma upto_enum_len_less:
   "\<lbrakk> n \<le> length [a, b .e. c]; n \<noteq> 0 \<rbrakk> \<Longrightarrow> a \<le> c"
   unfolding upto_enum_step_def
   by (simp split: if_split_asm)
 
 lemma length_upto_enum_step:
   fixes x :: "'a :: len word"
   shows "x \<le> z \<Longrightarrow> length [x , y .e. z] = (unat ((z - x) div (y - x))) + 1"
   unfolding upto_enum_step_def
   by (simp add: upto_enum_red)
 
 lemma map_length_unfold_one:
   fixes x :: "'a::len word"
   assumes xv: "Suc (unat x) < 2 ^ LENGTH('a)"
   and     ax: "a < x"
   shows   "map f [a .e. x] = f a # map f [a + 1 .e. x]"
   by (subst word_upto_Cons_eq, auto, fact+)
 
 lemma upto_enum_set_conv2:
   fixes a :: "'a::len word"
   shows "set [a .e. b] = {a .. b}"
   by auto
 
 lemma of_nat_unat [simp]:
   "of_nat \<circ> unat = id"
   by (rule ext, simp)
 
 lemma Suc_unat_minus_one [simp]:
   "x \<noteq> 0 \<Longrightarrow> Suc (unat (x - 1)) = unat x"
   by (metis Suc_diff_1 unat_gt_0 unat_minus_one)
 
 lemma word_add_le_dest:
   fixes i :: "'a :: len word"
   assumes le: "i + k \<le> j + k"
   and    uik: "unat i + unat k < 2 ^ len_of TYPE ('a)"
   and    ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "i \<le> j"
   using uik ujk le
   by (auto simp: word_le_nat_alt iffD1 [OF unat_add_lem] elim: add_le_mono1)
 
 lemma mask_shift:
   "(x && ~~ (mask y)) >> y = x >> y"
   by word_eqI
 
 lemma word_add_le_mono1:
   fixes i :: "'a :: len word"
   assumes ij: "i \<le> j"
   and    ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "i + k \<le> j + k"
 proof -
   from ij ujk have jk: "unat i + unat k < 2 ^ len_of TYPE ('a)"
     by (auto elim: order_le_less_subst2 simp: word_le_nat_alt elim: add_le_mono1)
 
   then show ?thesis using ujk ij
     by (auto simp: word_le_nat_alt iffD1 [OF unat_add_lem])
 qed
 
 lemma word_add_le_mono2:
   fixes i :: "'a :: len word"
   shows "\<lbrakk>i \<le> j; unat j + unat k < 2 ^ LENGTH('a)\<rbrakk> \<Longrightarrow> k + i \<le> k + j"
   by (subst field_simps, subst field_simps, erule (1) word_add_le_mono1)
 
 lemma word_add_le_iff:
   fixes i :: "'a :: len word"
   assumes uik: "unat i + unat k < 2 ^ len_of TYPE ('a)"
   and     ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "(i + k \<le> j + k) = (i \<le> j)"
 proof
   assume "i \<le> j"
   show "i + k \<le> j + k" by (rule word_add_le_mono1) fact+
 next
   assume "i + k \<le> j + k"
   show "i \<le> j" by (rule word_add_le_dest) fact+
 qed
 
 lemma word_add_less_mono1:
   fixes i :: "'a :: len word"
   assumes ij: "i < j"
   and    ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "i + k < j + k"
 proof -
   from ij ujk have jk: "unat i + unat k < 2 ^ len_of TYPE ('a)"
     by (auto elim: order_le_less_subst2 simp: word_less_nat_alt elim: add_less_mono1)
 
   then show ?thesis using ujk ij
     by (auto simp: word_less_nat_alt iffD1 [OF unat_add_lem])
 qed
 
 lemma word_add_less_dest:
   fixes i :: "'a :: len word"
   assumes le: "i + k < j + k"
   and    uik: "unat i + unat k < 2 ^ len_of TYPE ('a)"
   and    ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "i < j"
   using uik ujk le
   by (auto simp: word_less_nat_alt iffD1 [OF unat_add_lem] elim: add_less_mono1)
 
 lemma word_add_less_iff:
   fixes i :: "'a :: len word"
   assumes uik: "unat i + unat k < 2 ^ len_of TYPE ('a)"
   and     ujk: "unat j + unat k < 2 ^ len_of TYPE ('a)"
   shows  "(i + k < j + k) = (i < j)"
 proof
   assume "i < j"
   show "i + k < j + k" by (rule word_add_less_mono1) fact+
 next
   assume "i + k < j + k"
   show "i < j" by (rule word_add_less_dest) fact+
 qed
 
 lemma shiftr_div_2n':
   "unat (w >> n) = unat w div 2 ^ n"
   apply (unfold unat_eq_nat_uint)
   apply (subst shiftr_div_2n)
   apply (subst nat_div_distrib)
    apply simp
   apply (simp add: nat_power_eq)
   done
 
 lemma shiftl_shiftr_id:
   assumes nv: "n < LENGTH('a)"
   and     xv: "x < 2 ^ (LENGTH('a) - n)"
   shows "x << n >> n = (x::'a::len word)"
   apply (simp add: shiftl_t2n)
   apply (rule word_unat.Rep_eqD)
   apply (subst shiftr_div_2n')
   apply (cases n)
    apply simp
   apply (subst iffD1 [OF unat_mult_lem])+
    apply (subst unat_power_lower[OF nv])
    apply (rule nat_less_power_trans [OF _ order_less_imp_le [OF nv]])
    apply (rule order_less_le_trans [OF unat_mono [OF xv] order_eq_refl])
    apply (rule unat_power_lower)
    apply simp
   apply (subst unat_power_lower[OF nv])
   apply simp
   done
 
 lemma ucast_shiftl_eq_0:
   fixes w :: "'a :: len word"
   shows "\<lbrakk> n \<ge> LENGTH('b) \<rbrakk> \<Longrightarrow> ucast (w << n) = (0 :: 'b :: len word)"
   by (case_tac "size w \<le> n", clarsimp simp: shiftl_zero_size)
      (clarsimp simp: not_le ucast_bl bl_shiftl bang_eq test_bit_of_bl rev_nth nth_append)
 
 lemma word_mult_less_iff:
   fixes i :: "'a :: len word"
   assumes knz: "0 < k"
   and     uik: "unat i * unat k < 2 ^ len_of TYPE ('a)"
   and     ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows  "(i * k < j * k) = (i < j)"
   using assms by (rule word_mult_less_cancel)
 
 lemma word_le_imp_diff_le:
   fixes n :: "'a::len word"
   shows "\<lbrakk>k \<le> n; n \<le> m\<rbrakk> \<Longrightarrow> n - k \<le> m"
   by (auto simp: unat_sub word_le_nat_alt)
 
 lemma word_less_imp_diff_less:
   fixes n :: "'a::len word"
   shows "\<lbrakk>k \<le> n; n < m\<rbrakk> \<Longrightarrow> n - k < m"
   by (clarsimp simp: unat_sub word_less_nat_alt
              intro!: less_imp_diff_less)
 
 lemma word_mult_le_mono1:
   fixes i :: "'a :: len word"
   assumes ij: "i \<le> j"
   and    knz: "0 < k"
   and    ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows  "i * k \<le> j * k"
 proof -
   from ij ujk knz have jk: "unat i * unat k < 2 ^ len_of TYPE ('a)"
     by (auto elim: order_le_less_subst2 simp: word_le_nat_alt elim: mult_le_mono1)
 
   then show ?thesis using ujk knz ij
     by (auto simp: word_le_nat_alt iffD1 [OF unat_mult_lem])
 qed
 
 lemma word_mult_le_iff:
   fixes i :: "'a :: len word"
   assumes knz: "0 < k"
   and     uik: "unat i * unat k < 2 ^ len_of TYPE ('a)"
   and     ujk: "unat j * unat k < 2 ^ len_of TYPE ('a)"
   shows  "(i * k \<le> j * k) = (i \<le> j)"
 proof
   assume "i \<le> j"
   show "i * k \<le> j * k" by (rule word_mult_le_mono1) fact+
 next
   assume p: "i * k \<le> j * k"
 
   have "0 < unat k" using knz by (simp add: word_less_nat_alt)
   then show "i \<le> j" using p
     by (clarsimp simp: word_le_nat_alt iffD1 [OF unat_mult_lem uik]
       iffD1 [OF unat_mult_lem ujk])
 qed
 
 lemma word_diff_less:
   fixes n :: "'a :: len word"
   shows "\<lbrakk>0 < n; 0 < m; n \<le> m\<rbrakk> \<Longrightarrow> m - n < m"
   apply (subst word_less_nat_alt)
   apply (subst unat_sub)
    apply assumption
   apply (rule diff_less)
    apply (simp_all add: word_less_nat_alt)
    done
 
 lemma MinI:
   assumes fa: "finite A"
   and     ne: "A \<noteq> {}"
   and     xv: "m \<in> A"
   and    min: "\<forall>y \<in> A. m \<le> y"
   shows "Min A = m" using fa ne xv min
 proof (induct A arbitrary: m rule: finite_ne_induct)
   case singleton then show ?case by simp
 next
   case (insert y F)
 
   from insert.prems have yx: "m \<le> y" and fx: "\<forall>y \<in> F. m \<le> y" by auto
   have "m \<in> insert y F" by fact
   then show ?case
   proof
     assume mv: "m = y"
 
     have mlt: "m \<le> Min F"
       by (rule iffD2 [OF Min_ge_iff [OF insert.hyps(1) insert.hyps(2)] fx])
 
     show ?case
       apply (subst Min_insert [OF insert.hyps(1) insert.hyps(2)])
       apply (subst mv [symmetric])
       apply (auto simp: min_def mlt)
       done
   next
     assume "m \<in> F"
     then have mf: "Min F = m"
       by (rule insert.hyps(4) [OF _ fx])
 
     show ?case
       apply (subst Min_insert [OF insert.hyps(1) insert.hyps(2)])
       apply (subst mf)
       apply (rule iffD2 [OF _ yx])
       apply (auto simp: min_def)
       done
   qed
 qed
 
 lemma length_upto_enum [simp]:
   fixes a :: "'a :: len word"
   shows "length [a .e. b] = Suc (unat b) - unat a"
   apply (simp add: word_le_nat_alt upto_enum_red)
   apply (clarsimp simp: Suc_diff_le)
   done
 
 lemma length_upto_enum_cases:
   fixes a :: "'a::len word"
   shows "length [a .e. b] = (if a \<le> b then Suc (unat b) - unat a else 0)"
   apply (case_tac "a \<le> b")
    apply (clarsimp)
   apply (clarsimp simp: upto_enum_def)
   apply unat_arith
   done
 
 lemma length_upto_enum_less_one:
   "\<lbrakk>a \<le> b; b \<noteq> 0\<rbrakk>
   \<Longrightarrow> length [a .e. b - 1] = unat (b - a)"
   apply clarsimp
   apply (subst unat_sub[symmetric], assumption)
   apply clarsimp
   done
 
 lemma drop_upto_enum:
   "drop (unat n) [0 .e. m] = [n .e. m]"
   apply (clarsimp simp: upto_enum_def)
   apply (induct m, simp)
   by (metis drop_map drop_upt plus_nat.add_0)
 
 lemma distinct_enum_upto' [simp]:
   "distinct [a::'a::len word .e. b]"
   apply (subst drop_upto_enum [symmetric])
   apply (rule distinct_drop)
   apply (rule distinct_enum_upto)
   done
 
 lemma length_interval:
   "\<lbrakk>set xs = {x. (a::'a::len word) \<le> x \<and> x \<le> b}; distinct xs\<rbrakk>
   \<Longrightarrow> length xs = Suc (unat b) - unat a"
   apply (frule distinct_card)
   apply (subgoal_tac "set xs = set [a .e. b]")
    apply (cut_tac distinct_card [where xs="[a .e. b]"])
     apply (subst (asm) length_upto_enum)
     apply clarsimp
    apply (rule distinct_enum_upto')
   apply simp
   done
 
 lemma not_empty_eq:
   "(S \<noteq> {}) = (\<exists>x. x \<in> S)"
   by auto
 
 lemma range_subset_lower:
   fixes c :: "'a ::linorder"
   shows "\<lbrakk> {a..b} \<subseteq> {c..d}; x \<in> {a..b} \<rbrakk> \<Longrightarrow> c \<le> a"
   apply (frule (1) subsetD)
   apply (rule classical)
   apply clarsimp
   done
 
 lemma range_subset_upper:
   fixes c :: "'a ::linorder"
   shows "\<lbrakk> {a..b} \<subseteq> {c..d}; x \<in> {a..b} \<rbrakk> \<Longrightarrow> b \<le> d"
   apply (frule (1) subsetD)
   apply (rule classical)
   apply clarsimp
   done
 
 lemma range_subset_eq:
   fixes a::"'a::linorder"
   assumes non_empty: "a \<le> b"
   shows "({a..b} \<subseteq> {c..d}) = (c \<le> a \<and> b \<le> d)"
   apply (insert non_empty)
   apply (rule iffI)
    apply (frule range_subset_lower [where x=a], simp)
    apply (drule range_subset_upper [where x=a], simp)
    apply simp
   apply auto
   done
 
 lemma range_eq:
   fixes a::"'a::linorder"
   assumes non_empty: "a \<le> b"
   shows "({a..b} = {c..d}) = (a = c \<and> b = d)"
   by (metis atLeastatMost_subset_iff eq_iff non_empty)
 
 lemma range_strict_subset_eq:
   fixes a::"'a::linorder"
   assumes non_empty: "a \<le> b"
   shows "({a..b} \<subset> {c..d}) = (c \<le> a \<and> b \<le> d \<and> (a = c \<longrightarrow> b \<noteq> d))"
   apply (insert non_empty)
   apply (subst psubset_eq)
   apply (subst range_subset_eq, assumption+)
   apply (subst range_eq, assumption+)
   apply simp
   done
 
 lemma range_subsetI:
   fixes x :: "'a :: order"
   assumes xX: "X \<le> x"
   and     yY: "y \<le> Y"
   shows   "{x .. y} \<subseteq> {X .. Y}"
   using xX yY by auto
 
 lemma set_False [simp]:
   "(set bs \<subseteq> {False}) = (True \<notin> set bs)" by auto
 
 declare of_nat_power [simp del]
 
 (* TODO: move to word *)
 lemma unat_of_bl_length:
   "unat (of_bl xs :: 'a::len word) < 2 ^ (length xs)"
 proof (cases "length xs < LENGTH('a)")
   case True
   then have "(of_bl xs::'a::len word) < 2 ^ length xs"
     by (simp add: of_bl_length_less)
   with True
   show ?thesis
     by (simp add: word_less_nat_alt word_unat_power unat_of_nat)
 next
   case False
   have "unat (of_bl xs::'a::len word) < 2 ^ LENGTH('a)"
     by (simp split: unat_split)
   also
   from False
   have "LENGTH('a) \<le> length xs" by simp
   then have "2 ^ LENGTH('a) \<le> (2::nat) ^ length xs"
     by (rule power_increasing) simp
   finally
   show ?thesis .
 qed
 
 lemma is_aligned_0'[simp]:
   "is_aligned 0 n"
   by (simp add: is_aligned_def)
 
 lemma p_assoc_help:
   fixes p :: "'a::{ring,power,numeral,one}"
   shows "p + 2^sz - 1 = p + (2^sz - 1)"
   by simp
 
 lemma word_add_increasing:
   fixes x :: "'a :: len word"
   shows "\<lbrakk> p + w \<le> x; p \<le> p + w \<rbrakk> \<Longrightarrow> p \<le> x"
   by unat_arith
 
 lemma word_random:
   fixes x :: "'a :: len word"
   shows "\<lbrakk> p \<le> p + x'; x \<le> x' \<rbrakk> \<Longrightarrow> p \<le> p + x"
   by unat_arith
 
 lemma word_sub_mono:
   "\<lbrakk> a \<le> c; d \<le> b; a - b \<le> a; c - d \<le> c \<rbrakk>
     \<Longrightarrow> (a - b) \<le> (c - d :: 'a :: len word)"
   by unat_arith
 
 lemma power_not_zero:
   "n < LENGTH('a::len) \<Longrightarrow> (2 :: 'a word) ^ n \<noteq> 0"
   by (metis p2_gt_0 word_neq_0_conv)
 
 lemma word_gt_a_gt_0:
   "a < n \<Longrightarrow> (0 :: 'a::len word) < n"
   apply (case_tac "n = 0")
    apply clarsimp
   apply (clarsimp simp: word_neq_0_conv)
   done
 
 lemma word_shift_nonzero:
   "\<lbrakk> (x::'a::len word) \<le> 2 ^ m; m + n < LENGTH('a::len); x \<noteq> 0\<rbrakk>
    \<Longrightarrow> x << n \<noteq> 0"
   apply (simp only: word_neq_0_conv word_less_nat_alt
                     shiftl_t2n mod_0 unat_word_ariths
                     unat_power_lower word_le_nat_alt)
   apply (subst mod_less)
    apply (rule order_le_less_trans)
     apply (erule mult_le_mono2)
    apply (subst power_add[symmetric])
    apply (rule power_strict_increasing)
     apply simp
    apply simp
   apply simp
   done
 
 lemma word_power_less_1 [simp]:
   "sz < LENGTH('a::len) \<Longrightarrow> (2::'a word) ^ sz - 1 < 2 ^ sz"
   apply (simp add: word_less_nat_alt)
   apply (subst unat_minus_one)
   apply (simp add: word_unat.Rep_inject [symmetric])
   apply simp
   done
 
 lemma nasty_split_lt:
   "\<lbrakk> (x :: 'a:: len word) < 2 ^ (m - n); n \<le> m; m < LENGTH('a::len) \<rbrakk>
      \<Longrightarrow> x * 2 ^ n + (2 ^ n - 1) \<le> 2 ^ m - 1"
   apply (simp only: add_diff_eq)
   apply (subst mult_1[symmetric], subst distrib_right[symmetric])
   apply (rule word_sub_mono)
      apply (rule order_trans)
       apply (rule word_mult_le_mono1)
         apply (rule inc_le)
         apply assumption
        apply (subst word_neq_0_conv[symmetric])
        apply (rule power_not_zero)
        apply simp
       apply (subst unat_power_lower, simp)+
       apply (subst power_add[symmetric])
       apply (rule power_strict_increasing)
        apply simp
       apply simp
      apply (subst power_add[symmetric])
      apply simp
     apply simp
    apply (rule word_sub_1_le)
    apply (subst mult.commute)
    apply (subst shiftl_t2n[symmetric])
    apply (rule word_shift_nonzero)
      apply (erule inc_le)
     apply simp
    apply (unat_arith)
   apply (drule word_power_less_1)
   apply simp
   done
 
 lemma nasty_split_less:
   "\<lbrakk>m \<le> n; n \<le> nm; nm < LENGTH('a::len); x < 2 ^ (nm - n)\<rbrakk>
    \<Longrightarrow> (x :: 'a word) * 2 ^ n + (2 ^ m - 1) < 2 ^ nm"
   apply (simp only: word_less_sub_le[symmetric])
   apply (rule order_trans [OF _ nasty_split_lt])
      apply (rule word_plus_mono_right)
       apply (rule word_sub_mono)
          apply (simp add: word_le_nat_alt)
         apply simp
        apply (simp add: word_sub_1_le[OF power_not_zero])
       apply (simp add: word_sub_1_le[OF power_not_zero])
      apply (rule is_aligned_no_wrap')
       apply (rule is_aligned_mult_triv2)
      apply simp
     apply (erule order_le_less_trans, simp)
    apply simp+
   done
 
 lemma int_not_emptyD:
   "A \<inter> B \<noteq> {} \<Longrightarrow> \<exists>x. x \<in> A \<and> x \<in> B"
   by (erule contrapos_np, clarsimp simp: disjoint_iff_not_equal)
 
 lemma unat_less_power:
   fixes k :: "'a::len word"
   assumes szv: "sz < LENGTH('a)"
   and     kv:  "k < 2 ^ sz"
   shows   "unat k < 2 ^ sz"
   using szv unat_mono [OF kv] by simp
 
 lemma unat_mult_power_lem:
   assumes kv: "k < 2 ^ (LENGTH('a::len) - sz)"
   shows "unat (2 ^ sz * of_nat k :: (('a::len) word)) = 2 ^ sz * k"
 proof (cases \<open>sz < LENGTH('a)\<close>)
   case True
   with assms show ?thesis
     by (simp add: unat_word_ariths take_bit_eq_mod mod_simps)
       (simp add: take_bit_nat_eq_self_iff nat_less_power_trans flip: take_bit_eq_mod)
 next
   case False
   with assms show ?thesis
     by simp
 qed
 
 lemma aligned_add_offset_no_wrap:
   fixes off :: "('a::len) word"
   and     x :: "'a word"
   assumes al: "is_aligned x sz"
   and   offv: "off < 2 ^ sz"
   shows  "unat x + unat off < 2 ^ LENGTH('a)"
 proof cases
   assume szv: "sz < LENGTH('a)"
   from al obtain k where xv: "x = 2 ^ sz * (of_nat k)"
     and kl: "k < 2 ^ (LENGTH('a) - sz)"
     by (auto elim: is_alignedE)
 
   show ?thesis using szv
     apply (subst xv)
     apply (subst unat_mult_power_lem[OF kl])
     apply (subst mult.commute, rule nat_add_offset_less)
       apply (rule less_le_trans[OF unat_mono[OF offv, simplified]])
       apply (erule eq_imp_le[OF unat_power_lower])
      apply (rule kl)
     apply simp
    done
 next
   assume "\<not> sz < LENGTH('a)"
   with offv show ?thesis by (simp add: not_less power_overflow )
 qed
 
 lemma aligned_add_offset_mod:
   fixes x :: "('a::len) word"
   assumes al: "is_aligned x sz"
   and     kv: "k < 2 ^ sz"
   shows   "(x + k) mod 2 ^ sz = k"
 proof cases
   assume szv: "sz < LENGTH('a)"
 
   have ux: "unat x + unat k < 2 ^ LENGTH('a)"
     by (rule aligned_add_offset_no_wrap) fact+
 
   show ?thesis using al szv
     apply -
     apply (erule is_alignedE)
     apply (subst word_unat.Rep_inject [symmetric])
     apply (subst unat_mod)
     apply (subst iffD1 [OF unat_add_lem], rule ux)
     apply simp
     apply (subst unat_mult_power_lem, assumption+)
     apply (simp)
     apply (rule mod_less[OF less_le_trans[OF unat_mono], OF kv])
     apply (erule eq_imp_le[OF unat_power_lower])
     done
 next
   assume "\<not> sz < LENGTH('a)"
   with al show ?thesis
     by (simp add: not_less power_overflow is_aligned_mask mask_eq_decr_exp
                   word_mod_by_0)
 qed
 
 lemma word_plus_mcs_4:
   "\<lbrakk>v + x \<le> w + x; x \<le> v + x\<rbrakk> \<Longrightarrow> v \<le> (w::'a::len word)"
   by uint_arith
 
 lemma word_plus_mcs_3:
   "\<lbrakk>v \<le> w; x \<le> w + x\<rbrakk> \<Longrightarrow> v + x \<le> w + (x::'a::len word)"
   by unat_arith
 
 lemma aligned_neq_into_no_overlap:
   fixes x :: "'a::len word"
   assumes neq: "x \<noteq> y"
   and     alx: "is_aligned x sz"
   and     aly: "is_aligned y sz"
   shows  "{x .. x + (2 ^ sz - 1)} \<inter> {y .. y + (2 ^ sz - 1)} = {}"
 proof cases
   assume szv: "sz < LENGTH('a)"
   show ?thesis
   proof (rule equals0I, clarsimp)
     fix z
     assume xb: "x \<le> z" and xt: "z \<le> x + (2 ^ sz - 1)"
       and yb: "y \<le> z" and yt: "z \<le> y + (2 ^ sz - 1)"
 
     have rl: "\<And>(p::'a word) k w. \<lbrakk>uint p + uint k < 2 ^ LENGTH('a); w = p + k; w \<le> p + (2 ^ sz - 1) \<rbrakk>
       \<Longrightarrow> k < 2 ^ sz"
       apply -
       apply simp
       apply (subst (asm) add.commute, subst (asm) add.commute, drule word_plus_mcs_4)
       apply (subst add.commute, subst no_plus_overflow_uint_size)
       apply (simp add: word_size_bl)
       apply (erule iffD1 [OF word_less_sub_le[OF szv]])
       done
 
     from xb obtain kx where
       kx: "z = x + kx" and
       kxl: "uint x + uint kx < 2 ^ LENGTH('a)"
       by (clarsimp dest!: word_le_exists')
 
     from yb obtain ky where
       ky: "z = y + ky" and
       kyl: "uint y + uint ky < 2 ^ LENGTH('a)"
       by (clarsimp dest!: word_le_exists')
 
     have "x = y"
     proof -
       have "kx = z mod 2 ^ sz"
       proof (subst kx, rule sym, rule aligned_add_offset_mod)
         show "kx < 2 ^ sz" by (rule rl) fact+
       qed fact+
 
       also have "\<dots> = ky"
       proof (subst ky, rule aligned_add_offset_mod)
         show "ky < 2 ^ sz"
           using kyl ky yt by (rule rl)
       qed fact+
 
       finally have kxky: "kx = ky" .
       moreover have "x + kx = y + ky" by (simp add: kx [symmetric] ky [symmetric])
       ultimately show ?thesis by simp
     qed
 
     then show False using neq by simp
   qed
 next
   assume "\<not> sz < LENGTH('a)"
   with neq alx aly
   have False by (simp add: is_aligned_mask mask_eq_decr_exp power_overflow)
   then show ?thesis ..
 qed
 
 lemma less_two_pow_divD:
   "\<lbrakk> (x :: nat) < 2 ^ n div 2 ^ m \<rbrakk>
     \<Longrightarrow> n \<ge> m \<and> (x < 2 ^ (n - m))"
   apply (rule context_conjI)
    apply (rule ccontr)
    apply (simp add: power_strict_increasing)
   apply (simp add: power_sub)
   done
 
 lemma less_two_pow_divI:
   "\<lbrakk> (x :: nat) < 2 ^ (n - m); m \<le> n \<rbrakk> \<Longrightarrow> x < 2 ^ n div 2 ^ m"
   by (simp add: power_sub)
 
 lemma word_less_two_pow_divI:
   "\<lbrakk> (x :: 'a::len word) < 2 ^ (n - m); m \<le> n; n < LENGTH('a) \<rbrakk> \<Longrightarrow> x < 2 ^ n div 2 ^ m"
   apply (simp add: word_less_nat_alt)
   apply (subst unat_word_ariths)
   apply (subst mod_less)
    apply (rule order_le_less_trans [OF div_le_dividend])
    apply (rule unat_lt2p)
   apply (simp add: power_sub)
   done
 
 lemma word_less_two_pow_divD:
   "\<lbrakk> (x :: 'a::len word) < 2 ^ n div 2 ^ m \<rbrakk>
      \<Longrightarrow> n \<ge> m \<and> (x < 2 ^ (n - m))"
   apply (cases "n < LENGTH('a)")
    apply (cases "m < LENGTH('a)")
     apply (simp add: word_less_nat_alt)
     apply (subst(asm) unat_word_ariths)
     apply (subst(asm) mod_less)
      apply (rule order_le_less_trans [OF div_le_dividend])
      apply (rule unat_lt2p)
     apply (clarsimp dest!: less_two_pow_divD)
    apply (simp add: power_overflow)
    apply (simp add: word_div_def)
   apply (simp add: power_overflow word_div_def)
   done
 
 lemma of_nat_less_two_pow_div_set:
   "\<lbrakk> n < LENGTH('a) \<rbrakk> \<Longrightarrow>
    {x. x < (2 ^ n div 2 ^ m :: 'a::len word)}
       = of_nat ` {k. k < 2 ^ n div 2 ^ m}"
   apply (simp add: image_def)
   apply (safe dest!: word_less_two_pow_divD less_two_pow_divD
              intro!: word_less_two_pow_divI)
    apply (rule_tac x="unat x" in exI)
    apply (simp add: power_sub[symmetric])
    apply (subst unat_power_lower[symmetric, where 'a='a])
     apply simp
    apply (erule unat_mono)
   apply (subst word_unat_power)
   apply (rule of_nat_mono_maybe)
    apply (rule power_strict_increasing)
     apply simp
    apply simp
   apply assumption
   done
 
 lemma  word_less_power_trans2:
   fixes n :: "'a::len word"
   shows "\<lbrakk>n < 2 ^ (m - k); k \<le> m; m < LENGTH('a)\<rbrakk> \<Longrightarrow> n * 2 ^ k < 2 ^ m"
   by (subst field_simps, rule word_less_power_trans)
 
 (* shadows the slightly weaker Word.nth_ucast *)
 lemma nth_ucast:
   "(ucast (w::'a::len word)::'b::len word) !! n =
    (w !! n \<and> n < min LENGTH('a) LENGTH('b))"
   by transfer (simp add: bit_take_bit_iff ac_simps)
 
 lemma ucast_less:
   "LENGTH('b) < LENGTH('a) \<Longrightarrow>
    (ucast (x :: 'b :: len word) :: ('a :: len word)) < 2 ^ LENGTH('b)"
   by (meson Word.nth_ucast test_bit_conj_lt le_def upper_bits_unset_is_l2p)
 
 lemma ucast_range_less:
   "LENGTH('a :: len) < LENGTH('b :: len) \<Longrightarrow>
    range (ucast :: 'a word \<Rightarrow> 'b word) = {x. x < 2 ^ len_of TYPE ('a)}"
   apply safe
    apply (erule ucast_less)
   apply (simp add: image_def)
   apply (rule_tac x="ucast x" in exI)
   by word_eqI_solve
 
 lemma word_power_less_diff:
   "\<lbrakk>2 ^ n * q < (2::'a::len word) ^ m; q < 2 ^ (LENGTH('a) - n)\<rbrakk> \<Longrightarrow> q < 2 ^ (m - n)"
   apply (case_tac "m \<ge> LENGTH('a)")
    apply (simp add: power_overflow)
   apply (case_tac "n \<ge> LENGTH('a)")
    apply (simp add: power_overflow)
   apply (cases "n = 0")
    apply simp
   apply (subst word_less_nat_alt)
   apply (subst unat_power_lower)
    apply simp
   apply (rule nat_power_less_diff)
   apply (simp add: word_less_nat_alt)
   apply (subst (asm) iffD1 [OF unat_mult_lem])
    apply (simp add:nat_less_power_trans)
   apply simp
   done
 
 lemmas word_diff_ls'' = word_diff_ls [where xa=x and x=x for x]
 lemmas word_diff_ls' = word_diff_ls'' [simplified]
 
 lemmas word_l_diffs' = word_l_diffs [where xa=x and x=x for x]
 lemmas word_l_diffs = word_l_diffs' [simplified]
 
 lemma is_aligned_diff:
   fixes m :: "'a::len word"
   assumes alm: "is_aligned m s1"
   and     aln: "is_aligned n s2"
   and    s2wb: "s2 < LENGTH('a)"
   and      nm: "m \<in> {n .. n + (2 ^ s2 - 1)}"
   and    s1s2: "s1 \<le> s2"
   and     s10: "0 < s1" (* Probably can be folded into the proof \<dots> *)
 shows  "\<exists>q. m - n = of_nat q * 2 ^ s1 \<and> q < 2 ^ (s2 - s1)"
 proof -
   have rl: "\<And>m s. \<lbrakk> m < 2 ^ (LENGTH('a) - s); s < LENGTH('a) \<rbrakk> \<Longrightarrow> unat ((2::'a word) ^ s * of_nat m) = 2 ^ s * m"
   proof -
     fix m :: nat and  s
     assume m: "m < 2 ^ (LENGTH('a) - s)" and s: "s < LENGTH('a)"
     then have "unat ((of_nat m) :: 'a word) = m"
       apply (subst unat_of_nat)
       apply (subst mod_less)
        apply (erule order_less_le_trans)
        apply (rule power_increasing)
         apply simp_all
       done
 
     then show "?thesis m s" using s m
       apply (subst iffD1 [OF unat_mult_lem])
       apply (simp add: nat_less_power_trans)+
       done
   qed
   have s1wb: "s1 < LENGTH('a)" using s2wb s1s2 by simp
   from alm obtain mq where mmq: "m = 2 ^ s1 * of_nat mq" and mq: "mq < 2 ^ (LENGTH('a) - s1)"
     by (auto elim: is_alignedE simp: field_simps)
   from aln obtain nq where nnq: "n = 2 ^ s2 * of_nat nq" and nq: "nq < 2 ^ (LENGTH('a) - s2)"
     by (auto elim: is_alignedE simp: field_simps)
   from s1s2 obtain sq where sq: "s2 = s1 + sq" by (auto simp: le_iff_add)
 
   note us1 = rl [OF mq s1wb]
   note us2 = rl [OF nq s2wb]
 
   from nm have "n \<le> m" by clarsimp
   then have "(2::'a word) ^ s2 * of_nat nq \<le> 2 ^ s1 * of_nat mq" using nnq mmq by simp
   then have "2 ^ s2 * nq \<le> 2 ^ s1 * mq" using s1wb s2wb
     by (simp add: word_le_nat_alt us1 us2)
   then have nqmq: "2 ^ sq * nq \<le> mq" using sq by (simp add: power_add)
 
   have "m - n = 2 ^ s1 * of_nat mq - 2 ^ s2 * of_nat nq" using mmq nnq by simp
   also have "\<dots> = 2 ^ s1 * of_nat mq - 2 ^ s1 * 2 ^ sq * of_nat nq" using sq by (simp add: power_add)
   also have "\<dots> = 2 ^ s1 * (of_nat mq - 2 ^ sq * of_nat nq)" by (simp add: field_simps)
   also have "\<dots> = 2 ^ s1 * of_nat (mq - 2 ^ sq * nq)" using s1wb s2wb us1 us2 nqmq
     by (simp add:  word_unat_power)
   finally have mn: "m - n = of_nat (mq - 2 ^ sq * nq) * 2 ^ s1" by simp
   moreover
   from nm have "m - n \<le> 2 ^ s2 - 1"
     by - (rule word_diff_ls', (simp add: field_simps)+)
   then have "(2::'a word) ^ s1 * of_nat (mq - 2 ^ sq * nq) < 2 ^ s2" using mn s2wb by (simp add: field_simps)
   then have "of_nat (mq - 2 ^ sq * nq) < (2::'a word) ^ (s2 - s1)"
   proof (rule word_power_less_diff)
     have mm: "mq - 2 ^ sq * nq < 2 ^ (LENGTH('a) - s1)" using mq by simp
     moreover from s10 have "LENGTH('a) - s1 < LENGTH('a)"
       by (rule diff_less, simp)
     ultimately show "of_nat (mq - 2 ^ sq * nq) < (2::'a word) ^ (LENGTH('a) - s1)"
       using take_bit_nat_less_self_iff [of \<open>LENGTH('a)\<close> \<open>mq - 2 ^ sq * nq\<close>]
       apply (auto simp add: word_less_nat_alt not_le not_less)
       apply (metis take_bit_nat_eq_self_iff)
       done
   qed
   then have "mq - 2 ^ sq * nq < 2 ^ (s2 - s1)" using mq s2wb
     apply (simp add: word_less_nat_alt take_bit_eq_mod)
     apply (subst (asm) mod_less)
     apply auto
      apply (rule order_le_less_trans)
       apply (rule diff_le_self)
      apply (erule order_less_le_trans)
     apply simp
     done
   ultimately show ?thesis
     by auto
 qed
 
 lemma word_less_sub_1:
   "x < (y :: 'a :: len word) \<Longrightarrow> x \<le> y - 1"
   by (fact word_le_minus_one_leq)
 
 lemma word_sub_mono2:
   "\<lbrakk> a + b \<le> c + d; c \<le> a; b \<le> a + b; d \<le> c + d \<rbrakk>
     \<Longrightarrow> b \<le> (d :: 'a :: len word)"
   apply (drule(1) word_sub_mono)
     apply simp
    apply simp
   apply simp
   done
 
 lemma word_not_le:
   "(\<not> x \<le> (y :: 'a :: len word)) = (y < x)"
   by fastforce
 
 lemma word_subset_less:
   "\<lbrakk> {x .. x + r - 1} \<subseteq> {y .. y + s - 1};
      x \<le> x + r - 1; y \<le> y + (s :: 'a :: len word) - 1;
      s \<noteq> 0 \<rbrakk>
      \<Longrightarrow> r \<le> s"
   apply (frule subsetD[where c=x])
    apply simp
   apply (drule subsetD[where c="x + r - 1"])
    apply simp
   apply (clarsimp simp: add_diff_eq[symmetric])
   apply (drule(1) word_sub_mono2)
     apply (simp_all add: olen_add_eqv[symmetric])
   apply (erule word_le_minus_cancel)
   apply (rule ccontr)
   apply (simp add: word_not_le)
   done
 
 lemma uint_power_lower:
   "n < LENGTH('a) \<Longrightarrow> uint (2 ^ n :: 'a :: len word) = (2 ^ n :: int)"
   by (rule uint_2p_alt)
 
 lemma power_le_mono:
   "\<lbrakk>2 ^ n \<le> (2::'a::len word) ^ m; n < LENGTH('a); m < LENGTH('a)\<rbrakk>
    \<Longrightarrow> n \<le> m"
   apply (clarsimp simp add: le_less)
   apply safe
   apply (simp add: word_less_nat_alt)
   apply (simp only: uint_arith_simps(3))
   apply (drule uint_power_lower)+
   apply simp
   done
 
 lemma sublist_equal_part:
   "prefix xs ys \<Longrightarrow> take (length xs) ys = xs"
   by (clarsimp simp: prefix_def)
 
 lemma two_power_eq:
   "\<lbrakk>n < LENGTH('a); m < LENGTH('a)\<rbrakk>
    \<Longrightarrow> ((2::'a::len word) ^ n = 2 ^ m) = (n = m)"
   apply safe
   apply (rule order_antisym)
    apply (simp add: power_le_mono[where 'a='a])+
   done
 
 lemma prefix_length_less:
   "strict_prefix xs ys \<Longrightarrow> length xs < length ys"
   apply (clarsimp simp: strict_prefix_def)
   apply (frule prefix_length_le)
   apply (rule ccontr, simp)
   apply (clarsimp simp: prefix_def)
   done
 
 lemmas take_less = take_strict_prefix
 
 lemma not_prefix_longer:
   "\<lbrakk> length xs > length ys \<rbrakk> \<Longrightarrow> \<not> prefix xs ys"
   by (clarsimp dest!: prefix_length_le)
 
 lemma of_bl_length:
   "length xs < LENGTH('a) \<Longrightarrow> of_bl xs < (2 :: 'a::len word) ^ length xs"
   by (simp add: of_bl_length_less)
 
 lemma unat_of_nat_eq:
   "x < 2 ^ LENGTH('a) \<Longrightarrow> unat (of_nat x ::'a::len word) = x"
   by (rule unat_of_nat_len)
 
 lemma unat_eq_of_nat:
   "n < 2 ^ LENGTH('a) \<Longrightarrow> (unat (x :: 'a::len word) = n) = (x = of_nat n)"
   by transfer
     (auto simp add: take_bit_of_nat nat_eq_iff take_bit_nat_eq_self_iff intro: sym)
 
 lemma unat_less_helper:
   "x < of_nat n \<Longrightarrow> unat x < n"
   apply (simp add: word_less_nat_alt)
   apply (erule order_less_le_trans)
   apply (simp add: take_bit_eq_mod)
   done
 
 lemma nat_uint_less_helper:
   "nat (uint y) = z \<Longrightarrow> x < y \<Longrightarrow> nat (uint x) < z"
   apply (erule subst)
   apply (subst unat_eq_nat_uint [symmetric])
   apply (subst unat_eq_nat_uint [symmetric])
   by (simp add: unat_mono)
 
 lemma of_nat_0:
   "\<lbrakk>of_nat n = (0::'a::len word); n < 2 ^ LENGTH('a)\<rbrakk> \<Longrightarrow> n = 0"
   by transfer (simp add: take_bit_eq_mod)
 
 lemma word_leq_le_minus_one:
   "\<lbrakk> x \<le> y; x \<noteq> 0 \<rbrakk> \<Longrightarrow> x - 1 < (y :: 'a :: len word)"
   apply (simp add: word_less_nat_alt word_le_nat_alt)
   apply (subst unat_minus_one)
    apply assumption
   apply (cases "unat x")
    apply (simp add: unat_eq_zero)
   apply arith
   done
 
 lemma of_nat_inj:
   "\<lbrakk>x < 2 ^ LENGTH('a); y < 2 ^ LENGTH('a)\<rbrakk> \<Longrightarrow>
    (of_nat x = (of_nat y :: 'a :: len word)) = (x = y)"
   by (simp add: word_unat.norm_eq_iff [symmetric])
 
 lemma map_prefixI:
   "prefix xs ys \<Longrightarrow> prefix (map f xs) (map f ys)"
   by (clarsimp simp: prefix_def)
 
 lemma if_Some_None_eq_None:
   "((if P then Some v else None) = None) = (\<not> P)"
   by simp
 
 lemma CollectPairFalse [iff]:
   "{(a,b). False} = {}"
   by (simp add: split_def)
 
 lemma if_conj_dist:
   "((if b then w else x) \<and> (if b then y else z) \<and> X) =
   ((if b then w \<and> y else x \<and> z) \<and> X)"
   by simp
 
 lemma if_P_True1:
   "Q \<Longrightarrow> (if P then True else Q)"
   by simp
 
 lemma if_P_True2:
   "Q \<Longrightarrow> (if P then Q else True)"
   by simp
 
 lemma list_all2_induct [consumes 1, case_names Nil Cons]:
   assumes lall: "list_all2 Q xs ys"
   and     nilr: "P [] []"
   and    consr: "\<And>x xs y ys. \<lbrakk>list_all2 Q xs ys; Q x y; P xs ys\<rbrakk> \<Longrightarrow> P (x # xs) (y # ys)"
   shows  "P xs ys"
   using lall
 proof (induct rule: list_induct2 [OF list_all2_lengthD [OF lall]])
   case 1 then show ?case by auto fact+
 next
   case (2 x xs y ys)
 
   show ?case
   proof (rule consr)
     from "2.prems" show "list_all2 Q xs ys" and "Q x y" by simp_all
     then show "P xs ys" by (intro "2.hyps")
   qed
 qed
 
 lemma list_all2_induct_suffixeq [consumes 1, case_names Nil Cons]:
   assumes lall: "list_all2 Q as bs"
   and     nilr: "P [] []"
   and    consr: "\<And>x xs y ys.
   \<lbrakk>list_all2 Q xs ys; Q x y; P xs ys; suffix (x # xs) as; suffix (y # ys) bs\<rbrakk>
   \<Longrightarrow> P (x # xs) (y # ys)"
   shows  "P as bs"
 proof -
   define as' where "as' == as"
   define bs' where "bs' == bs"
 
   have "suffix as as' \<and> suffix bs bs'" unfolding as'_def bs'_def by simp
   then show ?thesis using lall
   proof (induct rule: list_induct2 [OF list_all2_lengthD [OF lall]])
     case 1 show ?case by fact
   next
     case (2 x xs y ys)
 
     show ?case
     proof (rule consr)
       from "2.prems" show "list_all2 Q xs ys" and "Q x y" by simp_all
       then show "P xs ys" using "2.hyps" "2.prems" by (auto dest: suffix_ConsD)
       from "2.prems" show "suffix (x # xs) as" and "suffix (y # ys) bs"
       by (auto simp: as'_def bs'_def)
     qed
   qed
 qed
 
 lemma upto_enum_step_shift:
   "\<lbrakk> is_aligned p n \<rbrakk> \<Longrightarrow>
   ([p , p + 2 ^ m .e. p + 2 ^ n - 1])
       = map ((+) p) [0, 2 ^ m .e. 2 ^ n - 1]"
   apply (erule is_aligned_get_word_bits)
    prefer 2
    apply (simp add: map_idI)
   apply (clarsimp simp: upto_enum_step_def)
   apply (frule is_aligned_no_overflow)
   apply (simp add: linorder_not_le [symmetric])
   done
 
 lemma upto_enum_step_shift_red:
   "\<lbrakk> is_aligned p sz; sz < LENGTH('a); us \<le> sz \<rbrakk>
      \<Longrightarrow> [p :: 'a :: len word, p + 2 ^ us .e. p + 2 ^ sz - 1]
           = map (\<lambda>x. p + of_nat x * 2 ^ us) [0 ..< 2 ^ (sz - us)]"
   apply (subst upto_enum_step_shift, assumption)
   apply (simp add: upto_enum_step_red)
   done
 
 lemma div_to_mult_word_lt:
   "\<lbrakk> (x :: 'a :: len word) \<le> y div z \<rbrakk> \<Longrightarrow> x * z \<le> y"
   apply (cases "z = 0")
    apply simp
   apply (simp add: word_neq_0_conv)
   apply (rule order_trans)
    apply (erule(1) word_mult_le_mono1)
    apply (simp add: unat_div)
    apply (rule order_le_less_trans [OF div_mult_le])
    apply simp
   apply (rule word_div_mult_le)
   done
 
 lemma upto_enum_step_subset:
   "set [x, y .e. z] \<subseteq> {x .. z}"
   apply (clarsimp simp: upto_enum_step_def linorder_not_less)
   apply (drule div_to_mult_word_lt)
   apply (rule conjI)
    apply (erule word_random[rotated])
    apply simp
   apply (rule order_trans)
    apply (erule word_plus_mono_right)
    apply simp
   apply simp
   done
 
 lemma shiftr_less_t2n':
   "\<lbrakk> x && mask (n + m) = x; m < LENGTH('a) \<rbrakk> \<Longrightarrow> x >> n < 2 ^ m" for x :: "'a :: len word"
   apply (simp add: word_size mask_eq_iff_w2p[symmetric])
   apply word_eqI
   apply (erule_tac x="na + n" in allE)
   apply fastforce
   done
 
 lemma shiftr_less_t2n:
   "x < 2 ^ (n + m) \<Longrightarrow> x >> n < 2 ^ m" for x :: "'a :: len word"
   apply (rule shiftr_less_t2n')
    apply (erule less_mask_eq)
   apply (rule ccontr)
   apply (simp add: not_less)
   apply (subst (asm) p2_eq_0[symmetric])
   apply (simp add: power_add)
   done
 
 lemma shiftr_eq_0:
   "n \<ge> LENGTH('a) \<Longrightarrow> ((w::'a::len word) >> n) = 0"
   apply (cut_tac shiftr_less_t2n'[of w n 0], simp)
    apply (simp add: mask_eq_iff)
   apply (simp add: lt2p_lem)
   apply simp
   done
 
 lemma shiftr_not_mask_0:
   "n+m \<ge> LENGTH('a :: len) \<Longrightarrow> ((w::'a::len word) >> n) && ~~ (mask m) = 0"
   apply (simp add: and_not_mask shiftr_less_t2n shiftr_shiftr)
   apply (subgoal_tac "w >> n + m = 0", simp)
   apply (simp add: le_mask_iff[symmetric] mask_eq_decr_exp le_def)
   apply (subst (asm) p2_gt_0[symmetric])
   apply (simp add: power_add not_less)
   done
 
 lemma shiftl_less_t2n:
   fixes x :: "'a :: len word"
   shows "\<lbrakk> x < (2 ^ (m - n)); m < LENGTH('a) \<rbrakk> \<Longrightarrow> (x << n) < 2 ^ m"
   apply (simp add: word_size mask_eq_iff_w2p[symmetric])
   apply word_eqI
   apply (erule_tac x="na - n" in allE)
   apply auto
   done
 
 lemma shiftl_less_t2n':
   "(x::'a::len word) < 2 ^ m \<Longrightarrow> m+n < LENGTH('a) \<Longrightarrow> x << n < 2 ^ (m + n)"
   by (rule shiftl_less_t2n) simp_all
 
 lemma ucast_ucast_mask:
   "(ucast :: 'a :: len word \<Rightarrow> 'b :: len word) (ucast x) = x && mask (len_of TYPE ('a))"
   by word_eqI
 
 lemma ucast_ucast_len:
   "\<lbrakk> x < 2 ^ LENGTH('b) \<rbrakk> \<Longrightarrow> ucast (ucast x::'b::len word) = (x::'a::len word)"
   apply (subst ucast_ucast_mask)
   apply (erule less_mask_eq)
   done
 
 lemma ucast_ucast_id:
   "LENGTH('a) < LENGTH('b) \<Longrightarrow> ucast (ucast (x::'a::len word)::'b::len word) = x"
   by (auto intro: ucast_up_ucast_id simp: is_up_def source_size_def target_size_def word_size)
 
 lemma unat_ucast:
   "unat (ucast x :: ('a :: len) word) = unat x mod 2 ^ (LENGTH('a))"
 proof -
   have \<open>2 ^ LENGTH('a) = nat (2 ^ LENGTH('a))\<close>
     by simp
   moreover have \<open>unat (UCAST('b \<rightarrow> 'a) x) = unat x mod nat (2 ^ LENGTH('a))\<close>
     by transfer (simp flip: nat_mod_distrib take_bit_eq_mod)
   ultimately show ?thesis
     by (simp only:)
 qed
 
 lemma ucast_less_ucast:
   "LENGTH('a) \<le> LENGTH('b) \<Longrightarrow>
    (ucast x < ((ucast (y :: 'a::len word)) :: 'b::len word)) = (x < y)"
   apply (simp add: word_less_nat_alt unat_ucast)
   apply (subst mod_less)
    apply(rule less_le_trans[OF unat_lt2p], simp)
   apply (subst mod_less)
    apply(rule less_le_trans[OF unat_lt2p], simp)
   apply simp
   done
 
 \<comment> \<open>This weaker version was previously called @{text ucast_less_ucast}. We retain it to
     support existing proofs.\<close>
 lemmas ucast_less_ucast_weak = ucast_less_ucast[OF order.strict_implies_order]
 
 lemma sints_subset:
   "m \<le> n \<Longrightarrow> sints m \<subseteq> sints n"
   apply (simp add: sints_num)
   apply clarsimp
   apply (rule conjI)
    apply (erule order_trans[rotated])
    apply simp
   apply (erule order_less_le_trans)
   apply simp
   done
 
 lemma up_scast_inj:
       "\<lbrakk> scast x = (scast y :: 'b :: len word); size x \<le> LENGTH('b) \<rbrakk>
          \<Longrightarrow> x = y"
   apply (unfold scast_eq)
   apply (subst(asm) word_sint.Abs_inject)
     apply (erule subsetD [OF sints_subset])
     apply (simp add: word_size)
    apply (erule subsetD [OF sints_subset])
    apply (simp add: word_size)
   apply simp
   done
 
 lemma up_scast_inj_eq:
   "LENGTH('a) \<le> len_of TYPE ('b) \<Longrightarrow>
   (scast x = (scast y::'b::len word)) = (x = (y::'a::len word))"
   by (fastforce dest: up_scast_inj simp: word_size)
 
 lemma nth_bounded:
   "\<lbrakk>(x :: 'a :: len word) !! n; x < 2 ^ m; m \<le> len_of TYPE ('a)\<rbrakk> \<Longrightarrow> n < m"
   apply (frule test_bit_size)
   apply (clarsimp simp: test_bit_bl word_size)
   apply (simp add: rev_nth)
   apply (subst(asm) is_aligned_add_conv[OF is_aligned_0',
                                         simplified add_0_left, rotated])
    apply assumption+
   apply (simp only: to_bl_0)
   apply (simp add: nth_append split: if_split_asm)
   done
 
 lemma is_aligned_add_or:
   "\<lbrakk>is_aligned p n; d < 2 ^ n\<rbrakk> \<Longrightarrow> p + d = p || d"
   by (rule word_plus_and_or_coroll, word_eqI) blast
 
 lemma two_power_increasing:
   "\<lbrakk> n \<le> m; m < LENGTH('a) \<rbrakk> \<Longrightarrow> (2 :: 'a :: len word) ^ n \<le> 2 ^ m"
   by (simp add: word_le_nat_alt)
 
 lemma is_aligned_add_less_t2n:
   "\<lbrakk>is_aligned (p::'a::len word) n; d < 2^n; n \<le> m; p < 2^m\<rbrakk> \<Longrightarrow> p + d < 2^m"
   apply (case_tac "m < LENGTH('a)")
    apply (subst mask_eq_iff_w2p[symmetric])
     apply (simp add: word_size)
    apply (simp add: is_aligned_add_or word_ao_dist less_mask_eq)
    apply (subst less_mask_eq)
     apply (erule order_less_le_trans)
     apply (erule(1) two_power_increasing)
    apply simp
   apply (simp add: power_overflow)
   done
 
 
 lemma aligned_offset_non_zero:
   "\<lbrakk> is_aligned x n; y < 2 ^ n; x \<noteq> 0 \<rbrakk> \<Longrightarrow> x + y \<noteq> 0"
   apply (cases "y = 0")
    apply simp
   apply (subst word_neq_0_conv)
   apply (subst gt0_iff_gem1)
   apply (erule is_aligned_get_word_bits)
    apply (subst field_simps[symmetric], subst plus_le_left_cancel_nowrap)
      apply (rule is_aligned_no_wrap')
       apply simp
      apply (rule word_leq_le_minus_one)
       apply simp
      apply assumption
     apply (erule (1) is_aligned_no_wrap')
    apply (simp add: gt0_iff_gem1 [symmetric] word_neq_0_conv)
   apply simp
   done
 
 lemmas mask_inner_mask = mask_eqs(1)
 
 lemma mask_add_aligned:
   "is_aligned p n \<Longrightarrow> (p + q) && mask n = q && mask n"
   apply (simp add: is_aligned_mask)
   apply (subst mask_inner_mask [symmetric])
   apply simp
   done
 
 lemma take_prefix:
   "(take (length xs) ys = xs) = prefix xs ys"
 proof (induct xs arbitrary: ys)
   case Nil then show ?case by simp
 next
   case Cons then show ?case by (cases ys) auto
 qed
 
 lemma cart_singleton_empty:
   "(S \<times> {e} = {}) = (S = {})"
   by blast
 
 lemma word_div_1:
   "(n :: 'a :: len word) div 1 = n"
   by (simp add: word_div_def)
 
 lemma word_minus_one_le:
   "-1 \<le> (x :: 'a :: len word) = (x = -1)"
   apply (insert word_n1_ge[where y=x])
   apply safe
   apply (erule(1) order_antisym)
   done
 
 lemma mask_out_sub_mask:
   "(x && ~~ (mask n)) = x - (x && (mask n))"
   by (simp add: field_simps word_plus_and_or_coroll2)
 
 lemma is_aligned_addD1:
   assumes al1: "is_aligned (x + y) n"
   and     al2: "is_aligned (x::'a::len word) n"
   shows "is_aligned y n"
   using al2
 proof (rule is_aligned_get_word_bits)
   assume "x = 0" then show ?thesis using al1 by simp
 next
   assume nv: "n < LENGTH('a)"
   from al1 obtain q1
     where xy: "x + y = 2 ^ n * of_nat q1" and "q1 < 2 ^ (LENGTH('a) - n)"
     by (rule is_alignedE)
   moreover from al2 obtain q2
     where x: "x = 2 ^ n * of_nat q2" and "q2 < 2 ^ (LENGTH('a) - n)"
     by (rule is_alignedE)
   ultimately have "y = 2 ^ n * (of_nat q1 - of_nat q2)"
     by (simp add: field_simps)
   then show ?thesis using nv by (simp add: is_aligned_mult_triv1)
 qed
 
 lemmas is_aligned_addD2 =
        is_aligned_addD1[OF subst[OF add.commute,
                                  of "%x. is_aligned x n" for n]]
 
 lemma is_aligned_add:
   "\<lbrakk>is_aligned p n; is_aligned q n\<rbrakk> \<Longrightarrow> is_aligned (p + q) n"
   by (simp add: is_aligned_mask mask_add_aligned)
 
 lemma word_le_add:
   fixes x :: "'a :: len word"
   shows "x \<le> y \<Longrightarrow> \<exists>n. y = x + of_nat n"
   by (rule exI [where x = "unat (y - x)"]) simp
 
 lemma word_plus_mcs_4':
   fixes x :: "'a :: len word"
   shows "\<lbrakk>x + v \<le> x + w; x \<le> x + v\<rbrakk> \<Longrightarrow> v \<le> w"
   apply (rule word_plus_mcs_4)
    apply (simp add: add.commute)
   apply (simp add: add.commute)
   done
 
 lemma shiftl_mask_is_0[simp]:
   "(x << n) && mask n = 0"
   apply (rule iffD1 [OF is_aligned_mask])
   apply (rule is_aligned_shiftl_self)
   done
 
 definition
   sum_map :: "('a \<Rightarrow> 'b) \<Rightarrow> ('c \<Rightarrow> 'd) \<Rightarrow> 'a + 'c \<Rightarrow> 'b + 'd" where
  "sum_map f g x \<equiv> case x of Inl v \<Rightarrow> Inl (f v) | Inr v' \<Rightarrow> Inr (g v')"
 
 lemma sum_map_simps[simp]:
   "sum_map f g (Inl v) = Inl (f v)"
   "sum_map f g (Inr w) = Inr (g w)"
   by (simp add: sum_map_def)+
 
 lemma if_and_helper:
   "(If x v v') && v'' = If x (v && v'') (v' && v'')"
   by (rule if_distrib)
 
 lemma unat_Suc2:
   fixes n :: "'a :: len word"
   shows
   "n \<noteq> -1 \<Longrightarrow> unat (n + 1) = Suc (unat n)"
   apply (subst add.commute, rule unatSuc)
   apply (subst eq_diff_eq[symmetric], simp add: minus_equation_iff)
   done
 
 lemmas word_unat_Rep_inject1 = word_unat.Rep_inject[where y=1]
 lemmas unat_eq_1 = unat_eq_0 word_unat_Rep_inject1[simplified]
 
 
 lemma rshift_sub_mask_eq:
   "(a >> (size a - b)) && mask b = a >> (size a - b)"
   using shiftl_shiftr2[where a=a and b=0 and c="size a - b"]
   apply (cases "b < size a")
    apply simp
   apply (simp add: linorder_not_less mask_eq_decr_exp word_size
                    p2_eq_0[THEN iffD2])
   done
 
 lemma shiftl_shiftr3:
   "b \<le> c \<Longrightarrow> a << b >> c = (a >> c - b) && mask (size a - c)"
   apply (cases "b = c")
    apply (simp add: shiftl_shiftr1)
   apply (simp add: shiftl_shiftr2)
   done
 
 lemma and_mask_shiftr_comm:
   "m\<le>size w \<Longrightarrow> (w && mask m) >> n = (w >> n) && mask (m-n)"
   by (simp add: and_mask shiftr_shiftr) (simp add: word_size shiftl_shiftr3)
 
 lemma and_mask_shiftl_comm:
   "m+n \<le> size w \<Longrightarrow> (w && mask m) << n = (w << n) && mask (m+n)"
   by (simp add: and_mask word_size shiftl_shiftl) (simp add: shiftl_shiftr1)
 
 lemma le_mask_shiftl_le_mask: "s = m + n \<Longrightarrow> x \<le> mask n \<Longrightarrow> x << m \<le> mask s"
   for x :: \<open>'a::len word\<close>
   by (simp add: le_mask_iff shiftl_shiftr3)
 
 lemma and_not_mask_twice:
   "(w && ~~ (mask n)) && ~~ (mask m) = w && ~~ (mask (max m n))"
   apply (simp add: and_not_mask)
   apply (case_tac "n<m";
          simp add: shiftl_shiftr2 shiftl_shiftr1 not_less max_def shiftr_shiftr shiftl_shiftl)
    apply (cut_tac and_mask_shiftr_comm [where w=w and m="size w" and n=m, simplified,symmetric])
    apply (simp add: word_size mask_eq_decr_exp)
   apply (cut_tac and_mask_shiftr_comm [where w=w and m="size w" and n=n, simplified,symmetric])
   apply (simp add: word_size mask_eq_decr_exp)
   done
 
 lemma word_less_cases:
   "x < y \<Longrightarrow> x = y - 1 \<or> x < y - (1 ::'a::len word)"
   apply (drule word_less_sub_1)
   apply (drule order_le_imp_less_or_eq)
   apply auto
   done
 
 lemma eq_eqI:
   "a = b \<Longrightarrow> (a = x) = (b = x)"
   by simp
 
 lemma mask_and_mask:
   "mask a && mask b = mask (min a b)"
   by word_eqI
 
 lemma mask_eq_0_eq_x:
   "(x && w = 0) = (x && ~~ w = x)"
   using word_plus_and_or_coroll2[where x=x and w=w]
   by auto
 
 lemma mask_eq_x_eq_0:
   "(x && w = x) = (x && ~~ w = 0)"
   using word_plus_and_or_coroll2[where x=x and w=w]
   by auto
 
 definition
   "limited_and (x :: 'a :: len word) y = (x && y = x)"
 
 lemma limited_and_eq_0:
   "\<lbrakk> limited_and x z; y && ~~ z = y \<rbrakk> \<Longrightarrow> x && y = 0"
   unfolding limited_and_def
   apply (subst arg_cong2[where f="(&&)"])
     apply (erule sym)+
   apply (simp(no_asm) add: word_bw_assocs word_bw_comms word_bw_lcs)
   done
 
 lemma limited_and_eq_id:
   "\<lbrakk> limited_and x z; y && z = z \<rbrakk> \<Longrightarrow> x && y = x"
   unfolding limited_and_def
   by (erule subst, fastforce simp: word_bw_lcs word_bw_assocs word_bw_comms)
 
 lemma lshift_limited_and:
   "limited_and x z \<Longrightarrow> limited_and (x << n) (z << n)"
   unfolding limited_and_def
   by (simp add: shiftl_over_and_dist[symmetric])
 
 lemma rshift_limited_and:
   "limited_and x z \<Longrightarrow> limited_and (x >> n) (z >> n)"
   unfolding limited_and_def
   by (simp add: shiftr_over_and_dist[symmetric])
 
 lemmas limited_and_simps1 = limited_and_eq_0 limited_and_eq_id
 
 lemmas is_aligned_limited_and
     = is_aligned_neg_mask_eq[unfolded mask_eq_decr_exp, folded limited_and_def]
 
 lemma compl_of_1: "~~ 1 = (-2 :: 'a :: len word)"
   by simp
 
 lemmas limited_and_simps = limited_and_simps1
        limited_and_simps1[OF is_aligned_limited_and]
        limited_and_simps1[OF lshift_limited_and]
        limited_and_simps1[OF rshift_limited_and]
        limited_and_simps1[OF rshift_limited_and, OF is_aligned_limited_and]
        compl_of_1 shiftl_shiftr1[unfolded word_size mask_eq_decr_exp]
        shiftl_shiftr2[unfolded word_size mask_eq_decr_exp]
 
 lemma split_word_eq_on_mask:
   "(x = y) = (x && m = y && m \<and> x && ~~ m = y && ~~ m)"
   by safe word_eqI_solve
 
 lemma map2_Cons_2_3:
   "(map2 f xs (y # ys) = (z # zs)) = (\<exists>x xs'. xs = x # xs' \<and> f x y = z \<and> map2 f xs' ys = zs)"
   by (case_tac xs, simp_all)
 
 lemma map2_xor_replicate_False:
   "map2 (\<lambda>x y. x \<longleftrightarrow> \<not> y) xs (replicate n False) = take n xs"
   apply (induct xs arbitrary: n, simp)
   apply (case_tac n; simp)
   done
 
 lemma word_and_1_shiftl:
   "x && (1 << n) = (if x !! n then (1 << n) else 0)" for x :: "'a :: len word"
   by word_eqI_solve
 
 lemmas word_and_1_shiftls'
     = word_and_1_shiftl[where n=0]
       word_and_1_shiftl[where n=1]
       word_and_1_shiftl[where n=2]
 
 lemmas word_and_1_shiftls = word_and_1_shiftls' [simplified]
 
 lemma word_and_mask_shiftl:
   "x && (mask n << m) = ((x >> m) && mask n) << m"
   by word_eqI_solve
 
 lemma plus_Collect_helper:
   "(+) x ` {xa. P (xa :: 'a :: len word)} = {xa. P (xa - x)}"
   by (fastforce simp add: image_def)
 
 lemma plus_Collect_helper2:
   "(+) (- x) ` {xa. P (xa :: 'a :: len word)} = {xa. P (x + xa)}"
   using plus_Collect_helper [of "- x" P] by (simp add: ac_simps)
 
 lemma word_FF_is_mask:
   "0xFF = (mask 8 :: 'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 lemma word_1FF_is_mask:
   "0x1FF = (mask 9 :: 'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 lemma ucast_of_nat_small:
   "x < 2 ^ LENGTH('a) \<Longrightarrow> ucast (of_nat x :: 'a :: len word) = (of_nat x :: 'b :: len word)"
   apply (rule sym, subst word_unat.inverse_norm)
   apply (simp add: ucast_eq of_nat_nat[symmetric] take_bit_eq_mod)
   done
 
 lemma word_le_make_less:
   fixes x :: "'a :: len word"
   shows "y \<noteq> -1 \<Longrightarrow> (x \<le> y) = (x < (y + 1))"
   apply safe
   apply (erule plus_one_helper2)
   apply (simp add: eq_diff_eq[symmetric])
   done
 
 lemmas finite_word = finite [where 'a="'a::len word"]
 
 lemma word_to_1_set:
   "{0 ..< (1 :: 'a :: len word)} = {0}"
   by fastforce
 
 lemma range_subset_eq2:
   "{a :: 'a :: len word .. b} \<noteq> {} \<Longrightarrow> ({a .. b} \<subseteq> {c .. d}) = (c \<le> a \<and> b \<le> d)"
   by simp
 
 lemma word_leq_minus_one_le:
   fixes x :: "'a::len word"
   shows "\<lbrakk>y \<noteq> 0; x \<le> y - 1 \<rbrakk> \<Longrightarrow> x < y"
   using le_m1_iff_lt word_neq_0_conv by blast
 
 lemma word_count_from_top:
   "n \<noteq> 0 \<Longrightarrow> {0 ..< n :: 'a :: len word} = {0 ..< n - 1} \<union> {n - 1}"
   apply (rule set_eqI, rule iffI)
    apply simp
    apply (drule word_le_minus_one_leq)
    apply (rule disjCI)
    apply simp
   apply simp
   apply (erule word_leq_minus_one_le)
   apply fastforce
   done
 
 lemma word_minus_one_le_leq:
   "\<lbrakk> x - 1 < y \<rbrakk> \<Longrightarrow> x \<le> (y :: 'a :: len word)"
   apply (cases "x = 0")
    apply simp
   apply (simp add: word_less_nat_alt word_le_nat_alt)
   apply (subst(asm) unat_minus_one)
    apply (simp add: word_less_nat_alt)
   apply (cases "unat x")
    apply (simp add: unat_eq_zero)
   apply arith
   done
 
 lemma mod_mod_power:
   fixes k :: nat
   shows "k mod 2 ^ m mod 2 ^ n = k mod 2 ^ (min m n)"
 proof (cases "m \<le> n")
   case True
 
   then have "k mod 2 ^ m mod 2 ^ n = k mod 2 ^ m"
     apply -
     apply (subst mod_less [where n = "2 ^ n"])
     apply (rule order_less_le_trans [OF mod_less_divisor])
     apply simp+
     done
   also have "\<dots> = k mod  2 ^ (min m n)" using True by simp
   finally show ?thesis .
 next
   case False
   then have "n < m" by simp
   then obtain d where md: "m = n + d"
     by (auto dest: less_imp_add_positive)
   then have "k mod 2 ^ m = 2 ^ n * (k div 2 ^ n mod 2 ^ d) + k mod 2 ^ n"
     by (simp add: mod_mult2_eq power_add)
   then have "k mod 2 ^ m mod 2 ^ n = k mod 2 ^ n"
     by (simp add: mod_add_left_eq)
   then show ?thesis using False
     by simp
 qed
 
 lemma word_div_less:
   "m < n \<Longrightarrow> m div n = 0" for m :: "'a :: len word"
   by (simp add: unat_mono word_arith_nat_defs(6))
 
 lemma word_must_wrap:
   "\<lbrakk> x \<le> n - 1; n \<le> x \<rbrakk> \<Longrightarrow> n = (0 :: 'a :: len word)"
   using dual_order.trans sub_wrap word_less_1 by blast
 
 lemma range_subset_card:
   "\<lbrakk> {a :: 'a :: len word .. b} \<subseteq> {c .. d}; b \<ge> a \<rbrakk> \<Longrightarrow> d \<ge> c \<and> d - c \<ge> b - a"
   using word_sub_le word_sub_mono by fastforce
 
 lemma less_1_simp:
   "n - 1 < m = (n \<le> (m :: 'a :: len word) \<and> n \<noteq> 0)"
   by unat_arith
 
 lemma alignUp_div_helper:
   fixes a :: "'a::len word"
   assumes kv: "k < 2 ^ (LENGTH('a) - n)"
   and     xk: "x = 2 ^ n * of_nat k"
   and    le: "a \<le> x"
   and    sz: "n < LENGTH('a)"
   and   anz: "a mod 2 ^ n \<noteq> 0"
   shows "a div 2 ^ n < of_nat k"
 proof -
   have kn: "unat (of_nat k :: 'a word) * unat ((2::'a word) ^ n) < 2 ^ LENGTH('a)"
     using xk kv sz
     apply (subst unat_of_nat_eq)
      apply (erule order_less_le_trans)
      apply simp
     apply (subst unat_power_lower, simp)
     apply (subst mult.commute)
     apply (rule nat_less_power_trans)
      apply simp
     apply simp
     done
 
   have "unat a div 2 ^ n * 2 ^ n \<noteq> unat a"
   proof -
     have "unat a = unat a div 2 ^ n * 2 ^ n + unat a mod 2 ^ n"
       by (simp add: div_mult_mod_eq)
     also have "\<dots> \<noteq> unat a div 2 ^ n * 2 ^ n" using sz anz
       by (simp add: unat_arith_simps)
     finally show ?thesis ..
   qed
 
   then have "a div 2 ^ n * 2 ^ n < a" using sz anz
     apply (subst word_less_nat_alt)
     apply (subst unat_word_ariths)
     apply (subst unat_div)
     apply simp
     apply (rule order_le_less_trans [OF mod_less_eq_dividend])
     apply (erule order_le_neq_trans [OF div_mult_le])
     done
 
   also from xk le have "\<dots> \<le> of_nat k * 2 ^ n" by (simp add: field_simps)
   finally show ?thesis using sz kv
     apply -
     apply (erule word_mult_less_dest [OF _ _ kn])
     apply (simp add: unat_div)
     apply (rule order_le_less_trans [OF div_mult_le])
     apply (rule unat_lt2p)
     done
 qed
 
 lemma nat_mod_power_lem:
   fixes a :: nat
   shows "1 < a \<Longrightarrow> a ^ n mod a ^ m = (if m \<le> n then 0 else a ^ n)"
   apply (clarsimp)
   apply (clarsimp simp add: le_iff_add power_add)
   done
 
 lemma power_mod_div:
   fixes x :: "nat"
   shows "x mod 2 ^ n div 2 ^ m = x div 2 ^ m mod 2 ^ (n - m)" (is "?LHS = ?RHS")
 proof (cases "n \<le> m")
   case True
   then have "?LHS = 0"
     apply -
     apply (rule div_less)
     apply (rule order_less_le_trans [OF mod_less_divisor]; simp)
     done
   also have "\<dots> = ?RHS" using True
     by simp
   finally show ?thesis .
 next
   case False
   then have lt: "m < n" by simp
   then obtain q where nv: "n = m + q" and "0 < q"
     by (auto dest: less_imp_Suc_add)
 
   then have "x mod 2 ^ n = 2 ^ m * (x div 2 ^ m mod 2 ^ q) + x mod 2 ^ m"
     by (simp add: power_add mod_mult2_eq)
 
   then have "?LHS = x div 2 ^ m mod 2 ^ q"
     by (simp add: div_add1_eq)
 
   also have "\<dots> = ?RHS" using nv
     by simp
 
   finally show ?thesis .
 qed
 
 lemma word_power_mod_div:
   fixes x :: "'a::len word"
   shows "\<lbrakk> n < LENGTH('a); m < LENGTH('a)\<rbrakk>
   \<Longrightarrow> x mod 2 ^ n div 2 ^ m = x div 2 ^ m mod 2 ^ (n - m)"
   apply (simp add: word_arith_nat_div unat_mod power_mod_div)
   apply (subst unat_arith_simps(3))
   apply (subst unat_mod)
   apply (subst unat_of_nat)+
   apply (simp add: mod_mod_power min.commute)
   done
 
 lemma word_range_minus_1':
   fixes a :: "'a :: len word"
   shows "a \<noteq> 0 \<Longrightarrow> {a - 1<..b} = {a..b}"
   by (simp add: greaterThanAtMost_def atLeastAtMost_def greaterThan_def atLeast_def less_1_simp)
 
 lemma word_range_minus_1:
   fixes a :: "'a :: len word"
   shows "b \<noteq> 0 \<Longrightarrow> {a..b - 1} = {a..<b}"
   apply (simp add: atLeastLessThan_def atLeastAtMost_def atMost_def lessThan_def)
   apply (rule arg_cong [where f = "\<lambda>x. {a..} \<inter> x"])
   apply rule
    apply clarsimp
    apply (erule contrapos_pp)
    apply (simp add: linorder_not_less linorder_not_le word_must_wrap)
   apply (clarsimp)
   apply (drule word_le_minus_one_leq)
   apply (auto simp: word_less_sub_1)
   done
 
 lemma ucast_nat_def:
   "of_nat (unat x) = (ucast :: 'a :: len word \<Rightarrow> 'b :: len word) x"
   by transfer simp
 
 lemmas if_fun_split = if_apply_def2
 
 lemma i_hate_words_helper:
   "i \<le> (j - k :: nat) \<Longrightarrow> i \<le> j"
   by simp
 
 lemma i_hate_words:
   "unat (a :: 'a word) \<le> unat (b :: 'a :: len word) - Suc 0
     \<Longrightarrow> a \<noteq> -1"
   apply (frule i_hate_words_helper)
   apply (subst(asm) word_le_nat_alt[symmetric])
   apply (clarsimp simp only: word_minus_one_le)
   apply (simp only: linorder_not_less[symmetric])
   apply (erule notE)
   apply (rule diff_Suc_less)
   apply (subst neq0_conv[symmetric])
   apply (subst unat_eq_0)
   apply (rule notI, drule arg_cong[where f="(+) 1"])
   apply simp
   done
 
 lemma overflow_plus_one_self:
   "(1 + p \<le> p) = (p = (-1 :: 'a :: len word))"
   apply rule
   apply (rule ccontr)
    apply (drule plus_one_helper2)
    apply (rule notI)
    apply (drule arg_cong[where f="\<lambda>x. x - 1"])
    apply simp
    apply (simp add: field_simps)
   apply simp
   done
 
 lemma plus_1_less:
   "(x + 1 \<le> (x :: 'a :: len word)) = (x = -1)"
   apply (rule iffI)
    apply (rule ccontr)
    apply (cut_tac plus_one_helper2[where x=x, OF order_refl])
     apply simp
    apply clarsimp
    apply (drule arg_cong[where f="\<lambda>x. x - 1"])
    apply simp
   apply simp
   done
 
 lemma pos_mult_pos_ge:
   "[|x > (0::int); n>=0 |] ==> n * x >= n*1"
   apply (simp only: mult_left_mono)
   done
 
 lemma If_eq_obvious:
   "x \<noteq> z \<Longrightarrow> ((if P then x else y) = z) = (\<not> P \<and> y = z)"
   by simp
 
 lemma Some_to_the:
   "v = Some x \<Longrightarrow> x = the v"
   by simp
 
 lemma dom_if_Some:
   "dom (\<lambda>x. if P x then Some (f x) else g x) = {x. P x} \<union> dom g"
   by fastforce
 
 lemma dom_insert_absorb:
   "x \<in> dom f \<Longrightarrow> insert x (dom f) = dom f" by auto
 
 lemma emptyE2:
   "\<lbrakk> S = {}; x \<in> S \<rbrakk> \<Longrightarrow> P"
   by simp
 
 lemma mod_div_equality_div_eq:
   "a div b * b = (a - (a mod b) :: int)"
   by (simp add: field_simps)
 
 lemma zmod_helper:
   "n mod m = k \<Longrightarrow> ((n :: int) + a) mod m = (k + a) mod m"
   by (metis add.commute mod_add_right_eq)
 
 lemma int_div_sub_1:
   "\<lbrakk> m \<ge> 1 \<rbrakk> \<Longrightarrow> (n - (1 :: int)) div m = (if m dvd n then (n div m) - 1 else n div m)"
   apply (subgoal_tac "m = 0 \<or> (n - (1 :: int)) div m = (if m dvd n then (n div m) - 1 else n div m)")
    apply fastforce
   apply (subst mult_cancel_right[symmetric])
   apply (simp only: left_diff_distrib split: if_split)
   apply (simp only: mod_div_equality_div_eq)
   apply (clarsimp simp: field_simps)
   apply (clarsimp simp: dvd_eq_mod_eq_0)
   apply (cases "m = 1")
    apply simp
   apply (subst mod_diff_eq[symmetric], simp add: zmod_minus1)
   apply clarsimp
   apply (subst diff_add_cancel[where b=1, symmetric])
   apply (subst mod_add_eq[symmetric])
   apply (simp add: field_simps)
   apply (rule mod_pos_pos_trivial)
    apply (subst add_0_right[where a=0, symmetric])
    apply (rule add_mono)
     apply simp
    apply simp
   apply (cases "(n - 1) mod m = m - 1")
    apply (drule zmod_helper[where a=1])
    apply simp
   apply (subgoal_tac "1 + (n - 1) mod m \<le> m")
    apply simp
   apply (subst field_simps, rule zless_imp_add1_zle)
   apply simp
   done
 
 lemma ptr_add_image_multI:
   "\<lbrakk> \<And>x y. (x * val = y * val') = (x * val'' = y); x * val'' \<in> S \<rbrakk> \<Longrightarrow>
      ptr_add ptr (x * val) \<in> (\<lambda>p. ptr_add ptr (p * val')) ` S"
   apply (simp add: image_def)
   apply (erule rev_bexI)
   apply (rule arg_cong[where f="ptr_add ptr"])
   apply simp
   done
 
 lemma shift_times_fold:
   "(x :: 'a :: len word) * (2 ^ n) << m = x << (m + n)"
   by (simp add: shiftl_t2n ac_simps power_add)
 
 lemma word_plus_strict_mono_right:
   fixes x :: "'a :: len word"
   shows "\<lbrakk>y < z; x \<le> x + z\<rbrakk> \<Longrightarrow> x + y < x + z"
   by unat_arith
 
 lemma replicate_minus:
   "k < n \<Longrightarrow> replicate n False = replicate (n - k) False @ replicate k False"
   by (subst replicate_add [symmetric]) simp
 
 lemmas map_prod_split_imageI'
   = map_prod_imageI[where f="case_prod f" and g="case_prod g"
                     and a="(a, b)" and b="(c, d)" for a b c d f g]
 lemmas map_prod_split_imageI = map_prod_split_imageI'[simplified]
 
 lemma word_div_mult:
   "0 < c \<Longrightarrow> a < b * c \<Longrightarrow> a div c < b" for a b c :: "'a::len word"
   by (rule classical)
      (use div_to_mult_word_lt [of b a c] in
       \<open>auto simp add: word_less_nat_alt word_le_nat_alt unat_div\<close>)
 
 lemma word_less_power_trans_ofnat:
   "\<lbrakk>n < 2 ^ (m - k); k \<le> m; m < LENGTH('a)\<rbrakk>
    \<Longrightarrow> of_nat n * 2 ^ k < (2::'a::len word) ^ m"
   apply (subst mult.commute)
   apply (rule word_less_power_trans)
     apply (simp_all add: word_less_nat_alt less_le_trans take_bit_eq_mod)
   done
 
 lemma word_1_le_power:
   "n < LENGTH('a) \<Longrightarrow> (1 :: 'a :: len word) \<le> 2 ^ n"
   by (rule inc_le[where i=0, simplified], erule iffD2[OF p2_gt_0])
 
 lemma enum_word_div:
   fixes v :: "'a :: len word" shows
   "\<exists>xs ys. enum = xs @ [v] @ ys
              \<and> (\<forall>x \<in> set xs. x < v)
              \<and> (\<forall>y \<in> set ys. v < y)"
   apply (simp only: enum_word_def)
   apply (subst upt_add_eq_append'[where j="unat v"])
     apply simp
    apply (rule order_less_imp_le, simp)
   apply (simp add: upt_conv_Cons)
   apply (intro exI conjI)
     apply fastforce
    apply clarsimp
    apply (drule of_nat_mono_maybe[rotated, where 'a='a])
     apply simp
    apply simp
   apply (clarsimp simp: Suc_le_eq)
   apply (drule of_nat_mono_maybe[rotated, where 'a='a])
    apply simp
   apply simp
   done
 
 lemma of_bool_nth:
   "of_bool (x !! v) = (x >> v) && 1"
   by (simp add: test_bit_word_eq shiftr_word_eq bit_eq_iff)
     (auto simp add: bit_1_iff bit_and_iff bit_drop_bit_eq intro: ccontr)
 
 lemma unat_1_0:
   "1 \<le> (x::'a::len word) = (0 < unat x)"
   by (auto simp add: word_le_nat_alt)
 
 lemma x_less_2_0_1':
   fixes x :: "'a::len word"
   shows "\<lbrakk>LENGTH('a) \<noteq> 1; x < 2\<rbrakk> \<Longrightarrow> x = 0 \<or> x = 1"
   apply (cases \<open>2 \<le> LENGTH('a)\<close>)
   apply simp_all
   apply transfer
   apply auto
   apply (metis add.commute add.right_neutral even_two_times_div_two mod_div_trivial mod_pos_pos_trivial mult.commute mult_zero_left not_less not_take_bit_negative odd_two_times_div_two_succ) 
   done
 
 lemmas word_add_le_iff2 = word_add_le_iff [folded no_olen_add_nat]
 
 lemma of_nat_power:
   shows "\<lbrakk> p < 2 ^ x; x < len_of TYPE ('a) \<rbrakk> \<Longrightarrow> of_nat p < (2 :: 'a :: len word) ^ x"
   apply (rule order_less_le_trans)
    apply (rule of_nat_mono_maybe)
     apply (erule power_strict_increasing)
     apply simp
    apply assumption
   apply (simp add: word_unat_power)
   done
 
 lemma of_nat_n_less_equal_power_2:
   "n < LENGTH('a::len) \<Longrightarrow> ((of_nat n)::'a word) < 2 ^ n"
   apply (induct n)
    apply clarsimp
   apply clarsimp
   apply (metis of_nat_power n_less_equal_power_2 of_nat_Suc power_Suc)
   done
 
 lemma eq_mask_less:
   fixes w :: "'a::len word"
   assumes eqm: "w = w && mask n"
   and      sz: "n < len_of TYPE ('a)"
   shows "w < (2::'a word) ^ n"
   by (subst eqm, rule and_mask_less' [OF sz])
 
 lemma of_nat_mono_maybe':
   fixes Y :: "nat"
   assumes xlt: "x < 2 ^ len_of TYPE ('a)"
   assumes ylt: "y < 2 ^ len_of TYPE ('a)"
   shows   "(y < x) = (of_nat y < (of_nat x :: 'a :: len word))"
   apply (subst word_less_nat_alt)
   apply (subst unat_of_nat)+
   apply (subst mod_less)
    apply (rule ylt)
   apply (subst mod_less)
    apply (rule xlt)
   apply simp
   done
 
 lemma shiftr_mask_eq:
   "(x >> n) && mask (size x - n) = x >> n" for x :: "'a :: len word"
   by word_eqI_solve
 
 lemma shiftr_mask_eq':
   "m = (size x - n) \<Longrightarrow> (x >> n) && mask m = x >> n" for x :: "'a :: len word"
   by (simp add: shiftr_mask_eq)
 
 lemma dom_if:
   "dom (\<lambda>a. if a \<in> addrs then Some (f a) else g a)  = addrs \<union> dom g"
   by (auto simp: dom_def split: if_split)
 
 lemma less_is_non_zero_p1:
   fixes a :: "'a :: len word"
   shows "a < k \<Longrightarrow> a + 1 \<noteq> 0"
   apply (erule contrapos_pn)
   apply (drule max_word_wrap)
   apply (simp add: not_less)
   done
 
 lemma of_nat_mono_maybe_le:
   "\<lbrakk>x < 2 ^ LENGTH('a); y < 2 ^ LENGTH('a)\<rbrakk> \<Longrightarrow>
   (y \<le> x) = ((of_nat y :: 'a :: len word) \<le> of_nat x)"
   apply (clarsimp simp: le_less)
   apply (rule disj_cong)
    apply (rule of_nat_mono_maybe', assumption+)
   apply (simp add: word_unat.norm_eq_iff [symmetric])
   done
 
 lemma mask_AND_NOT_mask:
   "(w && ~~ (mask n)) && mask n = 0"
   by word_eqI
 
 lemma AND_NOT_mask_plus_AND_mask_eq:
   "(w && ~~ (mask n)) + (w && mask n) = w"
   by (subst word_plus_and_or_coroll; word_eqI_solve)
 
 lemma mask_eqI:
   fixes x :: "'a :: len word"
   assumes m1: "x && mask n = y && mask n"
   and     m2: "x && ~~ (mask n) = y && ~~ (mask n)"
   shows "x = y"
 proof (subst bang_eq, rule allI)
   fix m
 
   show "x !! m = y !! m"
   proof (cases "m < n")
     case True
     then have "x !! m = ((x && mask n) !! m)"
       by (simp add: word_size test_bit_conj_lt)
     also have "\<dots> = ((y && mask n) !! m)" using m1 by simp
     also have "\<dots> = y !! m" using True
       by (simp add: word_size test_bit_conj_lt)
     finally show ?thesis .
   next
     case False
     then have "x !! m = ((x && ~~ (mask n)) !! m)"
       by (simp add: neg_mask_test_bit test_bit_conj_lt)
     also have "\<dots> = ((y && ~~ (mask n)) !! m)" using m2 by simp
     also have "\<dots> = y !! m" using False
       by (simp add: neg_mask_test_bit test_bit_conj_lt)
     finally show ?thesis .
   qed
 qed
 
 lemma nat_less_power_trans2:
   fixes n :: nat
   shows "\<lbrakk>n < 2 ^ (m - k); k \<le> m\<rbrakk> \<Longrightarrow> n * 2 ^ k  < 2 ^ m"
   by (subst mult.commute, erule (1) nat_less_power_trans)
 
 lemma nat_move_sub_le: "(a::nat) + b \<le> c \<Longrightarrow> a \<le> c - b" by arith
 
 lemma neq_0_no_wrap:
   fixes x :: "'a :: len word"
   shows "\<lbrakk> x \<le> x + y; x \<noteq> 0 \<rbrakk> \<Longrightarrow> x + y \<noteq> 0"
   by clarsimp
 
 lemma plus_minus_one_rewrite:
   "v + (- 1 :: ('a :: {ring, one, uminus})) \<equiv> v - 1"
   by (simp add: field_simps)
 
 lemma power_minus_is_div:
   "b \<le> a \<Longrightarrow> (2 :: nat) ^ (a - b) = 2 ^ a div 2 ^ b"
   apply (induct a arbitrary: b)
    apply simp
   apply (erule le_SucE)
    apply (clarsimp simp:Suc_diff_le le_iff_add power_add)
   apply simp
   done
 
 lemma two_pow_div_gt_le:
   "v < 2 ^ n div (2 ^ m :: nat) \<Longrightarrow> m \<le> n"
   by (clarsimp dest!: less_two_pow_divD)
 
 lemma unatSuc2:
   fixes n :: "'a :: len word"
   shows "n + 1 \<noteq> 0 \<Longrightarrow> unat (n + 1) = Suc (unat n)"
   by (simp add: add.commute unatSuc)
 
 lemma word_of_nat_less:
   "\<lbrakk> n < unat x \<rbrakk> \<Longrightarrow> of_nat n < x"
   apply (simp add: word_less_nat_alt)
   apply (erule order_le_less_trans[rotated])
   apply (simp add: take_bit_eq_mod)
   done
 
 lemma word_of_nat_le:
   "n \<le> unat x \<Longrightarrow> of_nat n \<le> x"
   apply (simp add: word_le_nat_alt unat_of_nat)
   apply (erule order_trans[rotated])
   apply (simp add: take_bit_eq_mod)
   done
 
 lemma word_unat_less_le:
    "a \<le> of_nat b \<Longrightarrow> unat a \<le> b"
    by (metis eq_iff le_cases le_unat_uoi word_of_nat_le)
 
 lemma and_eq_0_is_nth:
   fixes x :: "'a :: len word"
   shows "y = 1 << n \<Longrightarrow> ((x && y) = 0) = (\<not> (x !! n))"
   apply safe
    apply (drule_tac u="(x && (1 << n))" and x=n in word_eqD)
    apply (simp add: nth_w2p)
    apply (simp add: test_bit_bin)
   apply word_eqI
   done
 
 lemmas arg_cong_Not = arg_cong [where f=Not]
 lemmas and_neq_0_is_nth = arg_cong_Not [OF and_eq_0_is_nth, simplified]
 
 lemma nth_is_and_neq_0:
   "(x::'a::len word) !! n = (x && 2 ^ n \<noteq> 0)"
   by (subst and_neq_0_is_nth; rule refl)
 
 lemma mask_Suc_0 : "mask (Suc 0) = (1 :: 'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 lemma ucast_ucast_add:
   fixes x :: "'a :: len word"
   fixes y :: "'b :: len word"
   shows
   "LENGTH('b) \<ge> LENGTH('a) \<Longrightarrow>
     ucast (ucast x + y) = x + ucast y"
   apply (rule word_unat.Rep_eqD)
   apply (simp add: unat_ucast unat_word_ariths mod_mod_power
                    min.absorb2 unat_of_nat)
   apply (subst mod_add_left_eq[symmetric])
   apply (simp add: mod_mod_power min.absorb2)
   apply (subst mod_add_right_eq)
   apply simp
   done
 
 lemma word_shift_zero:
   "\<lbrakk> x << n = 0; x \<le> 2^m; m + n < LENGTH('a)\<rbrakk> \<Longrightarrow> (x::'a::len word) = 0"
   apply (rule ccontr)
   apply (drule (2) word_shift_nonzero)
   apply simp
   done
 
 lemma bool_mask':
   fixes x :: "'a :: len word"
   shows "2 < LENGTH('a) \<Longrightarrow> (0 < x && 1) = (x && 1 = 1)"
   by (simp add: and_one_eq mod_2_eq_odd)
 
 lemma sint_eq_uint:
   "\<not> msb x \<Longrightarrow> sint x = uint x"
   apply (rule word_uint.Abs_eqD, subst word_sint.Rep_inverse)
     apply simp_all
   apply (cut_tac x=x in word_sint.Rep)
   apply (clarsimp simp add: uints_num sints_num)
   apply (rule conjI)
    apply (rule ccontr)
    apply (simp add: linorder_not_le word_msb_sint[symmetric])
   apply (erule order_less_le_trans)
   apply simp
   done
 
 lemma scast_eq_ucast:
   "\<not> msb x \<Longrightarrow> scast x = ucast x"
   apply (cases \<open>LENGTH('a)\<close>)
   apply simp
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_signed_iff bit_unsigned_iff min_def msb_word_eq)
   apply (erule notE)
   apply (metis le_less_Suc_eq test_bit_bin test_bit_word_eq)
   done
 
 lemma lt1_neq0:
   fixes x :: "'a :: len word"
   shows "(1 \<le> x) = (x \<noteq> 0)" by unat_arith
 
 lemma word_plus_one_nonzero:
   fixes x :: "'a :: len word"
   shows "\<lbrakk>x \<le> x + y; y \<noteq> 0\<rbrakk> \<Longrightarrow> x + 1 \<noteq> 0"
   apply (subst lt1_neq0 [symmetric])
   apply (subst olen_add_eqv [symmetric])
   apply (erule word_random)
   apply (simp add: lt1_neq0)
   done
 
 lemma word_sub_plus_one_nonzero:
   fixes n :: "'a :: len word"
   shows "\<lbrakk>n' \<le> n; n' \<noteq> 0\<rbrakk> \<Longrightarrow> (n - n') + 1 \<noteq> 0"
   apply (subst lt1_neq0 [symmetric])
   apply (subst olen_add_eqv [symmetric])
   apply (rule word_random [where x' = n'])
    apply simp
    apply (erule word_sub_le)
   apply (simp add: lt1_neq0)
   done
 
 lemma word_le_minus_mono_right:
   fixes x :: "'a :: len word"
   shows "\<lbrakk> z \<le> y; y \<le> x; z \<le> x \<rbrakk> \<Longrightarrow> x - y \<le> x - z"
   apply (rule word_sub_mono)
      apply simp
     apply assumption
    apply (erule word_sub_le)
   apply (erule word_sub_le)
   done
 
 lemma drop_append_miracle:
   "n = length xs \<Longrightarrow> drop n (xs @ ys) = ys"
   by simp
 
 lemma foldr_does_nothing_to_xf:
   "\<lbrakk> \<And>x s. x \<in> set xs \<Longrightarrow> xf (f x s) = xf s \<rbrakk> \<Longrightarrow> xf (foldr f xs s) = xf s"
   by (induct xs, simp_all)
 
 lemma nat_less_mult_monoish: "\<lbrakk> a < b; c < (d :: nat) \<rbrakk> \<Longrightarrow> (a + 1) * (c + 1) <= b * d"
   apply (drule Suc_leI)+
   apply (drule(1) mult_le_mono)
   apply simp
   done
 
 lemma word_0_sle_from_less[unfolded word_size]:
   "\<lbrakk> x < 2 ^ (size x - 1) \<rbrakk>  \<Longrightarrow> 0 <=s x"
   apply (clarsimp simp: word_sle_msb_le)
   apply (simp add: word_msb_nth)
   apply (subst (asm) word_test_bit_def [symmetric])
   apply (drule less_mask_eq)
   apply (drule_tac x="size x - 1" in word_eqD)
   apply (simp add: word_size)
   done
 
 lemma not_msb_from_less:
   "(v :: 'a word) < 2 ^ (LENGTH('a :: len) - 1) \<Longrightarrow> \<not> msb v"
   apply (clarsimp simp add: msb_nth)
   apply (drule less_mask_eq)
   apply (drule word_eqD, drule(1) iffD2)
   apply simp
   done
 
 lemma distinct_lemma: "f x \<noteq> f y \<Longrightarrow> x \<noteq> y" by auto
 
 
 lemma ucast_sub_ucast:
   fixes x :: "'a::len word"
   assumes "y \<le> x"
   assumes T: "LENGTH('a) \<le> LENGTH('b)"
   shows "ucast (x - y) = (ucast x - ucast y :: 'b::len word)"
 proof -
   from T
   have P: "unat x < 2 ^ LENGTH('b)" "unat y < 2 ^ LENGTH('b)"
     by (fastforce intro!: less_le_trans[OF unat_lt2p])+
   then show ?thesis
     by (simp add: unat_arith_simps unat_ucast assms[simplified unat_arith_simps])
 qed
 
 lemma word_1_0:
   "\<lbrakk>a + (1::('a::len) word) \<le> b; a < of_nat x\<rbrakk> \<Longrightarrow> a < b"
   apply transfer
   apply (subst (asm) take_bit_incr_eq)
    apply (auto simp add: diff_less_eq)
   using take_bit_int_less_exp le_less_trans by blast
 
 lemma unat_of_nat_less:"\<lbrakk> a < b; unat b = c \<rbrakk> \<Longrightarrow> a < of_nat c"
   by fastforce
 
 lemma word_le_plus_1: "\<lbrakk> (y::('a::len) word) < y + n; a < n \<rbrakk> \<Longrightarrow> y + a \<le> y + a + 1"
   by unat_arith
 
 lemma word_le_plus:"\<lbrakk>(a::('a::len) word) < a + b; c < b\<rbrakk> \<Longrightarrow> a \<le> a + c"
 by (metis order_less_imp_le word_random)
 
 (*
  * Basic signed arithemetic properties.
  *)
 
 lemma sint_minus1 [simp]: "(sint x = -1) = (x = -1)"
   by (metis sint_n1 word_sint.Rep_inverse')
 
 lemma sint_0 [simp]: "(sint x = 0) = (x = 0)"
   by (metis sint_0 word_sint.Rep_inverse')
 
 (* It is not always that case that "sint 1 = 1", because of 1-bit word sizes.
  * This lemma produces the different cases. *)
 lemma sint_1_cases:
   P if \<open>\<lbrakk> len_of TYPE ('a::len) = 1; (a::'a word) = 0; sint a = 0 \<rbrakk> \<Longrightarrow> P\<close>
      \<open>\<lbrakk> len_of TYPE ('a) = 1; a = 1; sint (1 :: 'a word) = -1 \<rbrakk> \<Longrightarrow> P\<close>
      \<open>\<lbrakk> len_of TYPE ('a) > 1; sint (1 :: 'a word) = 1 \<rbrakk> \<Longrightarrow> P\<close>
 proof (cases \<open>LENGTH('a) = 1\<close>)
   case True
   then have \<open>a = 0 \<or> a = 1\<close>
     by transfer auto
   with True that show ?thesis
     by auto
 next
   case False
   with that show ?thesis
     by (simp add: less_le Suc_le_eq)
 qed
 
 lemma sint_int_min:
   "sint (- (2 ^ (LENGTH('a) - Suc 0)) :: ('a::len) word) = - (2 ^ (LENGTH('a) - Suc 0))"
   apply (subst word_sint.Abs_inverse' [where r="- (2 ^ (LENGTH('a) - Suc 0))"])
     apply (clarsimp simp: sints_num)
    apply (clarsimp simp: wi_hom_syms word_of_int_2p)
   apply clarsimp
   done
 
 lemma sint_int_max_plus_1:
   "sint (2 ^ (LENGTH('a) - Suc 0) :: ('a::len) word) = - (2 ^ (LENGTH('a) - Suc 0))"
   apply (cases \<open>LENGTH('a)\<close>)
    apply simp_all
   apply (subst word_of_int_2p [symmetric])
   apply (subst int_word_sint)
   apply simp
   done
 
 lemma sbintrunc_eq_in_range:
   "(sbintrunc n x = x) = (x \<in> range (sbintrunc n))"
   "(x = sbintrunc n x) = (x \<in> range (sbintrunc n))"
   apply (simp_all add: image_def)
   apply (metis sbintrunc_sbintrunc)+
   done
 
 lemma sbintrunc_If:
   "- 3 * (2 ^ n) \<le> x \<and> x < 3 * (2 ^ n)
     \<Longrightarrow> sbintrunc n x = (if x < - (2 ^ n) then x + 2 * (2 ^ n)
         else if x \<ge> 2 ^ n then x - 2 * (2 ^ n) else x)"
   apply (simp add: no_sbintr_alt2, safe)
    apply (simp add: mod_pos_geq)
   apply (subst mod_add_self1[symmetric], simp)
   done
 
 lemma signed_arith_eq_checks_to_ord:
   "(sint a + sint b = sint (a + b ))
     = ((a <=s a + b) = (0 <=s b))"
   "(sint a - sint b = sint (a - b ))
     = ((0 <=s a - b) = (b <=s a))"
   "(- sint a = sint (- a)) = (0 <=s (- a) = (a <=s 0))"
   using sint_range'[where x=a] sint_range'[where x=b]
   by (simp_all add: sint_word_ariths word_sle_eq word_sless_alt sbintrunc_If)
 
 (* Basic proofs that signed word div/mod operations are
  * truncations of their integer counterparts. *)
 
 lemma signed_div_arith:
     "sint ((a::('a::len) word) sdiv b) = sbintrunc (LENGTH('a) - 1) (sint a sdiv sint b)"
   apply (subst word_sbin.norm_Rep [symmetric])
   apply (subst bin_sbin_eq_iff' [symmetric])
    apply simp
   apply (subst uint_sint [symmetric])
   apply (clarsimp simp: sdiv_int_def sdiv_word_def)
   apply transfer
   apply simp
   done
 
 lemma signed_mod_arith:
     "sint ((a::('a::len) word) smod b) = sbintrunc (LENGTH('a) - 1) (sint a smod sint b)"
  
   apply (subst word_sbin.norm_Rep [symmetric])
   apply (subst bin_sbin_eq_iff' [symmetric])
    apply simp
   apply (subst uint_sint [symmetric])
   apply (clarsimp simp: smod_int_def smod_word_def)
   using word_ubin.inverse_norm by force
 
 (* Signed word arithmetic overflow constraints. *)
 
 lemma signed_arith_ineq_checks_to_eq:
   "((- (2 ^ (size a - 1)) \<le> (sint a + sint b)) \<and> (sint a + sint b \<le> (2 ^ (size a - 1) - 1)))
     = (sint a + sint b = sint (a + b ))"
   "((- (2 ^ (size a - 1)) \<le> (sint a - sint b)) \<and> (sint a - sint b \<le> (2 ^ (size a - 1) - 1)))
     = (sint a - sint b = sint (a - b))"
   "((- (2 ^ (size a - 1)) \<le> (- sint a)) \<and> (- sint a) \<le> (2 ^ (size a - 1) - 1))
     = ((- sint a) = sint (- a))"
   "((- (2 ^ (size a - 1)) \<le> (sint a * sint b)) \<and> (sint a * sint b \<le> (2 ^ (size a - 1) - 1)))
     = (sint a * sint b = sint (a * b))"
   "((- (2 ^ (size a - 1)) \<le> (sint a sdiv sint b)) \<and> (sint a sdiv sint b \<le> (2 ^ (size a - 1) - 1)))
     = (sint a sdiv sint b = sint (a sdiv b))"
   "((- (2 ^ (size a - 1)) \<le> (sint a smod sint b)) \<and> (sint a smod sint b \<le> (2 ^ (size a - 1) - 1)))
     = (sint a smod sint b = sint (a smod b))"
   by (auto simp: sint_word_ariths word_size signed_div_arith signed_mod_arith
                     sbintrunc_eq_in_range range_sbintrunc)
 
 lemma signed_arith_sint:
   "((- (2 ^ (size a - 1)) \<le> (sint a + sint b)) \<and> (sint a + sint b \<le> (2 ^ (size a - 1) - 1)))
     \<Longrightarrow> sint (a + b) = (sint a + sint b)"
   "((- (2 ^ (size a - 1)) \<le> (sint a - sint b)) \<and> (sint a - sint b \<le> (2 ^ (size a - 1) - 1)))
     \<Longrightarrow> sint (a - b) = (sint a - sint b)"
   "((- (2 ^ (size a - 1)) \<le> (- sint a)) \<and> (- sint a) \<le> (2 ^ (size a - 1) - 1))
     \<Longrightarrow> sint (- a) = (- sint a)"
   "((- (2 ^ (size a - 1)) \<le> (sint a * sint b)) \<and> (sint a * sint b \<le> (2 ^ (size a - 1) - 1)))
     \<Longrightarrow> sint (a * b) = (sint a * sint b)"
   "((- (2 ^ (size a - 1)) \<le> (sint a sdiv sint b)) \<and> (sint a sdiv sint b \<le> (2 ^ (size a - 1) - 1)))
     \<Longrightarrow> sint (a sdiv b) = (sint a sdiv sint b)"
   "((- (2 ^ (size a - 1)) \<le> (sint a smod sint b)) \<and> (sint a smod sint b \<le> (2 ^ (size a - 1) - 1)))
     \<Longrightarrow> sint (a smod b) = (sint a smod sint b)"
   by (subst (asm) signed_arith_ineq_checks_to_eq; simp)+
 
 lemma signed_mult_eq_checks_double_size:
   assumes mult_le: "(2 ^ (len_of TYPE ('a) - 1) + 1) ^ 2 \<le> (2 :: int) ^ (len_of TYPE ('b) - 1)"
            and le: "2 ^ (LENGTH('a) - 1) \<le> (2 :: int) ^ (len_of TYPE ('b) - 1)"
   shows "(sint (a :: 'a :: len word) * sint b = sint (a * b))
        = (scast a * scast b = (scast (a * b) :: 'b :: len word))"
 proof -
   have P: "sbintrunc (size a - 1) (sint a * sint b) \<in> range (sbintrunc (size a - 1))"
     by simp
 
   have abs: "!! x :: 'a word. abs (sint x) < 2 ^ (size a - 1) + 1"
     apply (cut_tac x=x in sint_range')
     apply (simp add: abs_le_iff word_size)
     done
   have abs_ab: "abs (sint a * sint b) < 2 ^ (LENGTH('b) - 1)"
     using abs_mult_less[OF abs[where x=a] abs[where x=b]] mult_le
     by (simp add: abs_mult power2_eq_square word_size)
   define r s where \<open>r = LENGTH('a) - 1\<close> \<open>s = LENGTH('b) - 1\<close>
   then have \<open>LENGTH('a) = Suc r\<close> \<open>LENGTH('b) = Suc s\<close>
     \<open>size a = Suc r\<close> \<open>size b = Suc r\<close>
     by (simp_all add: word_size)
   then show ?thesis
     using P[unfolded range_sbintrunc] abs_ab le
     apply clarsimp
     apply (transfer fixing: r s)
     apply (auto simp add: signed_take_bit_int_eq_self simp flip: signed_take_bit_eq_iff_take_bit_eq)
     done
 qed
 
 (* Properties about signed division. *)
 
 lemma int_sdiv_simps [simp]:
     "(a :: int) sdiv 1 = a"
     "(a :: int) sdiv 0 = 0"
     "(a :: int) sdiv -1 = -a"
   apply (auto simp: sdiv_int_def sgn_if)
   done
 
 lemma sgn_div_eq_sgn_mult:
     "a div b \<noteq> 0 \<Longrightarrow> sgn ((a :: int) div b) = sgn (a * b)"
   apply (clarsimp simp: sgn_if zero_le_mult_iff neg_imp_zdiv_nonneg_iff not_less)
   apply (metis less_le mult_le_0_iff neg_imp_zdiv_neg_iff not_less pos_imp_zdiv_neg_iff zdiv_eq_0_iff)
   done
 
 lemma sgn_sdiv_eq_sgn_mult:
   "a sdiv b \<noteq> 0 \<Longrightarrow> sgn ((a :: int) sdiv b) = sgn (a * b)"
   by (auto simp: sdiv_int_def sgn_div_eq_sgn_mult sgn_mult)
 
 lemma int_sdiv_same_is_1 [simp]:
     "a \<noteq> 0 \<Longrightarrow> ((a :: int) sdiv b = a) = (b = 1)"
   apply (rule iffI)
    apply (clarsimp simp: sdiv_int_def)
    apply (subgoal_tac "b > 0")
     apply (case_tac "a > 0")
      apply (clarsimp simp: sgn_if)
     apply (clarsimp simp: algebra_split_simps not_less)
     apply (metis int_div_same_is_1 le_neq_trans minus_minus neg_0_le_iff_le neg_equal_0_iff_equal)
    apply (case_tac "a > 0")
     apply (case_tac "b = 0")
      apply clarsimp
     apply (rule classical)
     apply (clarsimp simp: sgn_mult not_less)
     apply (metis le_less neg_0_less_iff_less not_less_iff_gr_or_eq pos_imp_zdiv_neg_iff)
    apply (rule classical)
    apply (clarsimp simp: algebra_split_simps sgn_mult not_less sgn_if split: if_splits)
    apply (metis antisym less_le neg_imp_zdiv_nonneg_iff)
   apply (clarsimp simp: sdiv_int_def sgn_if)
   done
 
 lemma int_sdiv_negated_is_minus1 [simp]:
     "a \<noteq> 0 \<Longrightarrow> ((a :: int) sdiv b = - a) = (b = -1)"
   apply (clarsimp simp: sdiv_int_def)
   apply (rule iffI)
    apply (subgoal_tac "b < 0")
     apply (case_tac "a > 0")
      apply (clarsimp simp: sgn_if algebra_split_simps not_less)
     apply (case_tac "sgn (a * b) = -1")
      apply (clarsimp simp: not_less algebra_split_simps)
     apply (clarsimp simp: algebra_split_simps not_less)
    apply (rule classical)
    apply (case_tac "b = 0")
     apply (clarsimp simp: not_less sgn_mult)
    apply (case_tac "a > 0")
     apply (clarsimp simp: not_less sgn_mult)
     apply (metis less_le neg_less_0_iff_less not_less_iff_gr_or_eq pos_imp_zdiv_neg_iff)
    apply (clarsimp simp: not_less sgn_mult)
    apply (metis antisym_conv div_minus_right neg_imp_zdiv_nonneg_iff neg_le_0_iff_le not_less)
   apply (clarsimp simp: sgn_if)
   done
 
 lemma sdiv_int_range:
     "(a :: int) sdiv b \<in> { - (abs a) .. (abs a) }"
   apply (unfold sdiv_int_def)
   apply (subgoal_tac "(abs a) div (abs b) \<le> (abs a)")
-   apply (clarsimp simp: sgn_if)
-   apply (meson abs_ge_zero neg_le_0_iff_le nonneg_mod_div order_trans)
-  apply (metis abs_eq_0 abs_ge_zero div_by_0 zdiv_le_dividend zero_less_abs_iff)
+   apply (auto simp add: sgn_if not_less)
+      apply (metis le_less le_less_trans neg_equal_0_iff_equal neg_less_iff_less not_le pos_imp_zdiv_neg_iff)
+     apply (metis add.inverse_neutral div_int_pos_iff le_less neg_le_iff_le order_trans)
+    apply (metis div_minus_right le_less_trans neg_imp_zdiv_neg_iff neg_less_0_iff_less not_le)
+  using div_int_pos_iff apply fastforce
+  apply (metis abs_0_eq abs_ge_zero div_by_0 zdiv_le_dividend zero_less_abs_iff)
   done
 
 lemma word_sdiv_div1 [simp]:
     "(a :: ('a::len) word) sdiv 1 = a"
   apply (rule sint_1_cases [where a=a])
     apply (clarsimp simp: sdiv_word_def sdiv_int_def)
    apply (clarsimp simp: sdiv_word_def sdiv_int_def simp del: sint_minus1)
   apply (clarsimp simp: sdiv_word_def)
   done
 
 lemma sdiv_int_div_0 [simp]:
   "(x :: int) sdiv 0 = 0"
   by (clarsimp simp: sdiv_int_def)
 
 lemma sdiv_int_0_div [simp]:
   "0 sdiv (x :: int) = 0"
   by (clarsimp simp: sdiv_int_def)
 
 lemma word_sdiv_div0 [simp]:
     "(a :: ('a::len) word) sdiv 0 = 0"
   apply (auto simp: sdiv_word_def sdiv_int_def sgn_if)
   done
 
 lemma word_sdiv_div_minus1 [simp]:
     "(a :: ('a::len) word) sdiv -1 = -a"
   apply (auto simp: sdiv_word_def sdiv_int_def sgn_if)
   done
 
 lemmas word_sdiv_0 = word_sdiv_div0
 
 lemma sdiv_word_min:
     "- (2 ^ (size a - 1)) \<le> sint (a :: ('a::len) word) sdiv sint (b :: ('a::len) word)"
   apply (clarsimp simp: word_size)
   apply (cut_tac sint_range' [where x=a])
   apply (cut_tac sint_range' [where x=b])
   apply clarsimp
   apply (insert sdiv_int_range [where a="sint a" and b="sint b"])
   apply (clarsimp simp: max_def abs_if split: if_split_asm)
   done
 
 lemma sdiv_word_max:
     "(sint (a :: ('a::len) word) sdiv sint (b :: ('a::len) word) < (2 ^ (size a - 1))) =
           ((a \<noteq> - (2 ^ (size a - 1)) \<or> (b \<noteq> -1)))"
     (is "?lhs = (\<not> ?a_int_min \<or> \<not> ?b_minus1)")
 proof (rule classical)
   assume not_thesis: "\<not> ?thesis"
 
   have not_zero: "b \<noteq> 0"
     using not_thesis
     by (clarsimp)
 
   have result_range: "sint a sdiv sint b \<in> (sints (size a)) \<union> {2 ^ (size a - 1)}"
     apply (cut_tac sdiv_int_range [where a="sint a" and b="sint b"])
     apply (erule rev_subsetD)
     using sint_range' [where x=a]  sint_range' [where x=b]
     apply (auto simp: max_def abs_if word_size sints_num)
     done
 
   have result_range_overflow: "(sint a sdiv sint b = 2 ^ (size a - 1)) = (?a_int_min \<and> ?b_minus1)"
     apply (rule iffI [rotated])
      apply (clarsimp simp: sdiv_int_def sgn_if word_size sint_int_min)
     apply (rule classical)
     apply (case_tac "?a_int_min")
      apply (clarsimp simp: word_size sint_int_min)
      apply (metis diff_0_right
               int_sdiv_negated_is_minus1 minus_diff_eq minus_int_code(2)
               power_eq_0_iff sint_minus1 zero_neq_numeral)
     apply (subgoal_tac "abs (sint a) < 2 ^ (size a - 1)")
      apply (insert sdiv_int_range [where a="sint a" and b="sint b"])[1]
      apply (clarsimp simp: word_size)
     apply (insert sdiv_int_range [where a="sint a" and b="sint b"])[1]
     apply (insert word_sint.Rep [where x="a"])[1]
     apply (clarsimp simp: minus_le_iff word_size abs_if sints_num split: if_split_asm)
     apply (metis minus_minus sint_int_min word_sint.Rep_inject)
     done
 
   have result_range_simple: "(sint a sdiv sint b \<in> (sints (size a))) \<Longrightarrow> ?thesis"
     apply (insert sdiv_int_range [where a="sint a" and b="sint b"])
     apply (clarsimp simp: word_size sints_num sint_int_min)
     done
 
   show ?thesis
     apply (rule UnE [OF result_range result_range_simple])
      apply simp
     apply (clarsimp simp: word_size)
     using result_range_overflow
     apply (clarsimp simp: word_size)
     done
 qed
 
 lemmas sdiv_word_min' = sdiv_word_min [simplified word_size, simplified]
 lemmas sdiv_word_max' = sdiv_word_max [simplified word_size, simplified]
 
-lemmas word_sdiv_numerals_lhs = sdiv_word_def[where a="numeral x" for x]
-    sdiv_word_def[where a=0] sdiv_word_def[where a=1]
-
-lemmas word_sdiv_numerals = word_sdiv_numerals_lhs[where b="numeral y" for y]
-    word_sdiv_numerals_lhs[where b=0] word_sdiv_numerals_lhs[where b=1]
+lemmas word_sdiv_numerals_lhs = sdiv_word_def[where v="numeral x" for x]
+    sdiv_word_def[where v=0] sdiv_word_def[where v=1]
+
+lemmas word_sdiv_numerals = word_sdiv_numerals_lhs[where w="numeral y" for y]
+    word_sdiv_numerals_lhs[where w=0] word_sdiv_numerals_lhs[where w=1]
 
 (*
  * Signed modulo properties.
  *)
 
 lemma smod_int_alt_def:
      "(a::int) smod b = sgn (a) * (abs a mod abs b)"
   apply (clarsimp simp: smod_int_def sdiv_int_def)
   apply (clarsimp simp: minus_div_mult_eq_mod [symmetric] abs_sgn sgn_mult sgn_if algebra_split_simps)
   done
 
 lemma smod_int_range:
   "b \<noteq> 0 \<Longrightarrow> (a::int) smod b \<in> { - abs b + 1 .. abs b - 1 }"
   apply (case_tac  "b > 0")
    apply (insert pos_mod_conj [where a=a and b=b])[1]
    apply (insert pos_mod_conj [where a="-a" and b=b])[1]
    apply (auto simp: smod_int_alt_def algebra_simps sgn_if
               abs_if not_less add1_zle_eq [simplified add.commute])[1]
     apply (metis add_nonneg_nonneg int_one_le_iff_zero_less le_less less_add_same_cancel2 not_le pos_mod_conj)
   apply (metis (full_types) add.inverse_inverse eucl_rel_int eucl_rel_int_iff le_less_trans neg_0_le_iff_le)
   apply (insert neg_mod_conj [where a=a and b="b"])[1]
   apply (insert neg_mod_conj [where a="-a" and b="b"])[1]
   apply (clarsimp simp: smod_int_alt_def algebra_simps sgn_if
             abs_if not_less add1_zle_eq [simplified add.commute])
   apply (metis neg_0_less_iff_less neg_mod_conj not_le not_less_iff_gr_or_eq order_trans pos_mod_conj)
   done
 
 lemma smod_int_compares:
    "\<lbrakk> 0 \<le> a; 0 < b \<rbrakk> \<Longrightarrow> (a :: int) smod b < b"
    "\<lbrakk> 0 \<le> a; 0 < b \<rbrakk> \<Longrightarrow> 0 \<le> (a :: int) smod b"
    "\<lbrakk> a \<le> 0; 0 < b \<rbrakk> \<Longrightarrow> -b < (a :: int) smod b"
    "\<lbrakk> a \<le> 0; 0 < b \<rbrakk> \<Longrightarrow> (a :: int) smod b \<le> 0"
    "\<lbrakk> 0 \<le> a; b < 0 \<rbrakk> \<Longrightarrow> (a :: int) smod b < - b"
    "\<lbrakk> 0 \<le> a; b < 0 \<rbrakk> \<Longrightarrow> 0 \<le> (a :: int) smod b"
    "\<lbrakk> a \<le> 0; b < 0 \<rbrakk> \<Longrightarrow> (a :: int) smod b \<le> 0"
    "\<lbrakk> a \<le> 0; b < 0 \<rbrakk> \<Longrightarrow> b \<le> (a :: int) smod b"
   apply (insert smod_int_range [where a=a and b=b])
   apply (auto simp: add1_zle_eq smod_int_alt_def sgn_if)
   done
 
 lemma smod_int_mod_0 [simp]:
   "x smod (0 :: int) = x"
   by (clarsimp simp: smod_int_def)
 
 lemma smod_int_0_mod [simp]:
   "0 smod (x :: int) = 0"
   by (clarsimp simp: smod_int_alt_def)
 
 lemma smod_word_mod_0 [simp]:
   "x smod (0 :: ('a::len) word) = x"
   by (clarsimp simp: smod_word_def)
 
 lemma smod_word_0_mod [simp]:
   "0 smod (x :: ('a::len) word) = 0"
   by (clarsimp simp: smod_word_def)
 
 lemma smod_word_max:
     "sint (a::'a word) smod sint (b::'a word) < 2 ^ (LENGTH('a::len) - Suc 0)"
   apply (case_tac "b = 0")
    apply (insert word_sint.Rep [where x=a, simplified sints_num])[1]
    apply (clarsimp)
   apply (insert word_sint.Rep [where x="b", simplified sints_num])[1]
   apply (insert smod_int_range [where a="sint a" and b="sint b"])
   apply (clarsimp simp: abs_if split: if_split_asm)
   done
 
 lemma smod_word_min:
     "- (2 ^ (LENGTH('a::len) - Suc 0)) \<le> sint (a::'a word) smod sint (b::'a word)"
   apply (case_tac "b = 0")
    apply (insert word_sint.Rep [where x=a, simplified sints_num])[1]
    apply clarsimp
   apply (insert word_sint.Rep [where x=b, simplified sints_num])[1]
   apply (insert smod_int_range [where a="sint a" and b="sint b"])
   apply (clarsimp simp: abs_if add1_zle_eq split: if_split_asm)
   done
 
 lemma smod_word_alt_def:
   "(a :: ('a::len) word) smod b = a - (a sdiv b) * b"
   apply (cases \<open>a \<noteq> - (2 ^ (LENGTH('a) - 1)) \<or> b \<noteq> - 1\<close>)
    apply (clarsimp simp: smod_word_def sdiv_word_def smod_int_def
      simp flip: wi_hom_sub wi_hom_mult)
   apply (clarsimp simp: smod_word_def smod_int_def)
   done
 
-lemmas word_smod_numerals_lhs = smod_word_def[where a="numeral x" for x]
-    smod_word_def[where a=0] smod_word_def[where a=1]
-
-lemmas word_smod_numerals = word_smod_numerals_lhs[where b="numeral y" for y]
-    word_smod_numerals_lhs[where b=0] word_smod_numerals_lhs[where b=1]
+lemmas word_smod_numerals_lhs = smod_word_def[where v="numeral x" for x]
+    smod_word_def[where v=0] smod_word_def[where v=1]
+
+lemmas word_smod_numerals = word_smod_numerals_lhs[where w="numeral y" for y]
+    word_smod_numerals_lhs[where w=0] word_smod_numerals_lhs[where w=1]
 
 lemma sint_of_int_eq:
   "\<lbrakk> - (2 ^ (LENGTH('a) - 1)) \<le> x; x < 2 ^ (LENGTH('a) - 1) \<rbrakk> \<Longrightarrow> sint (of_int x :: ('a::len) word) = x"
   by (simp add: signed_take_bit_int_eq_self)
 
 lemma of_int_sint:
   "of_int (sint a) = a"
   by simp
 
 lemma nth_w2p_scast [simp]:
   "((scast ((2::'a::len signed word) ^ n) :: 'a word) !! m)
          \<longleftrightarrow> ((((2::'a::len  word) ^ n) :: 'a word) !! m)"
   apply (subst nth_w2p)
   apply (case_tac "n \<ge> LENGTH('a)")
    apply (subst power_overflow, simp)
    apply clarsimp
   apply (metis nth_w2p scast_eq test_bit_conj_lt
                len_signed nth_word_of_int word_sint.Rep_inverse)
   done
 
 lemma scast_2_power [simp]: "scast ((2 :: 'a::len signed word) ^ x) = ((2 :: 'a word) ^ x)"
   by (clarsimp simp: word_eq_iff)
 
 lemma scast_bit_test [simp]:
     "scast ((1 :: 'a::len signed word) << n) = (1 :: 'a word) << n"
   by (clarsimp simp: word_eq_iff)
 
 lemma ucast_nat_def':
   "of_nat (unat x) = (ucast :: 'a :: len word \<Rightarrow> ('b :: len) signed word) x"
   by (fact ucast_nat_def)
 
 lemma mod_mod_power_int:
   fixes k :: int
   shows "k mod 2 ^ m mod 2 ^ n = k mod 2 ^ (min m n)"
   by (metis bintrunc_bintrunc_min bintrunc_mod2p min.commute)
 
 (* Normalise combinations of scast and ucast. *)
 
 lemma ucast_distrib:
   fixes M :: "'a::len word \<Rightarrow> 'a::len word \<Rightarrow> 'a::len word"
   fixes M' :: "'b::len word \<Rightarrow> 'b::len word \<Rightarrow> 'b::len word"
   fixes L :: "int \<Rightarrow> int \<Rightarrow> int"
   assumes lift_M: "\<And>x y. uint (M x y) = L (uint x) (uint y)  mod 2 ^ LENGTH('a)"
   assumes lift_M': "\<And>x y. uint (M' x y) = L (uint x) (uint y)  mod 2 ^ LENGTH('b)"
   assumes distrib: "\<And>x y. (L (x mod (2 ^ LENGTH('b))) (y mod (2 ^ LENGTH('b)))) mod (2 ^ LENGTH('b))
                                = (L x y) mod (2 ^ LENGTH('b))"
   assumes is_down: "is_down (ucast :: 'a word \<Rightarrow> 'b word)"
   shows "ucast (M a b) = M' (ucast a) (ucast b)"
   apply (simp only: ucast_eq)
   apply (subst lift_M)
   apply (subst of_int_uint [symmetric], subst lift_M')
   apply (subst (1 2) int_word_uint)
   apply (subst word_ubin.norm_eq_iff [symmetric])
   apply (subst (1 2) bintrunc_mod2p)
   apply (insert is_down)
   apply (unfold is_down_def)
   apply (clarsimp simp: target_size source_size)
   apply (clarsimp simp: mod_mod_power_int min_def)
   apply (rule distrib [symmetric])
   done
 
 lemma ucast_down_add:
     "is_down (ucast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  ucast ((a :: 'a::len word) + b) = (ucast a + ucast b :: 'b::len word)"
   by (rule ucast_distrib [where L="(+)"], (clarsimp simp: uint_word_ariths)+, presburger, simp)
 
 lemma ucast_down_minus:
     "is_down (ucast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  ucast ((a :: 'a::len word) - b) = (ucast a - ucast b :: 'b::len word)"
   apply (rule ucast_distrib [where L="(-)"], (clarsimp simp: uint_word_ariths)+)
   apply (metis mod_diff_left_eq mod_diff_right_eq)
   apply simp
   done
 
 lemma ucast_down_mult:
     "is_down (ucast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  ucast ((a :: 'a::len word) * b) = (ucast a * ucast b :: 'b::len word)"
   apply (rule ucast_distrib [where L="(*)"], (clarsimp simp: uint_word_ariths)+)
   apply (metis mod_mult_eq)
   apply simp
   done
 
 lemma scast_distrib:
   fixes M :: "'a::len word \<Rightarrow> 'a::len word \<Rightarrow> 'a::len word"
   fixes M' :: "'b::len word \<Rightarrow> 'b::len word \<Rightarrow> 'b::len word"
   fixes L :: "int \<Rightarrow> int \<Rightarrow> int"
   assumes lift_M: "\<And>x y. uint (M x y) = L (uint x) (uint y)  mod 2 ^ LENGTH('a)"
   assumes lift_M': "\<And>x y. uint (M' x y) = L (uint x) (uint y)  mod 2 ^ LENGTH('b)"
   assumes distrib: "\<And>x y. (L (x mod (2 ^ LENGTH('b))) (y mod (2 ^ LENGTH('b)))) mod (2 ^ LENGTH('b))
                                = (L x y) mod (2 ^ LENGTH('b))"
   assumes is_down: "is_down (scast :: 'a word \<Rightarrow> 'b word)"
   shows "scast (M a b) = M' (scast a) (scast b)"
   apply (subst (1 2 3) down_cast_same [symmetric])
    apply (insert is_down)
    apply (clarsimp simp: is_down_def target_size source_size is_down)
   apply (rule ucast_distrib [where L=L, OF lift_M lift_M' distrib])
   apply (insert is_down)
   apply (clarsimp simp: is_down_def target_size source_size is_down)
   done
 
 lemma scast_down_add:
     "is_down (scast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  scast ((a :: 'a::len word) + b) = (scast a + scast b :: 'b::len word)"
   by (rule scast_distrib [where L="(+)"], (clarsimp simp: uint_word_ariths)+, presburger, simp)
 
 lemma scast_down_minus:
     "is_down (scast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  scast ((a :: 'a::len word) - b) = (scast a - scast b :: 'b::len word)"
   apply (rule scast_distrib [where L="(-)"], (clarsimp simp: uint_word_ariths)+)
   apply (metis mod_diff_left_eq mod_diff_right_eq)
   apply simp
   done
 
 lemma scast_down_mult:
     "is_down (scast:: 'a word \<Rightarrow> 'b word) \<Longrightarrow>  scast ((a :: 'a::len word) * b) = (scast a * scast b :: 'b::len word)"
   apply (rule scast_distrib [where L="(*)"], (clarsimp simp: uint_word_ariths)+)
   apply (metis mod_mult_eq)
   apply simp
   done
 
 lemma scast_ucast_1:
   "\<lbrakk> is_down (ucast :: 'a word \<Rightarrow> 'b word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
          (scast (ucast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = ucast a"
   by (metis down_cast_same ucast_eq ucast_down_wi)
 
 lemma scast_ucast_3:
   "\<lbrakk> is_down (ucast :: 'a word \<Rightarrow> 'c word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
          (scast (ucast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = ucast a"
   by (metis down_cast_same ucast_eq ucast_down_wi)
 
 lemma scast_ucast_4:
   "\<lbrakk> is_up (ucast :: 'a word \<Rightarrow> 'b word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
          (scast (ucast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = ucast a"
   by (metis down_cast_same ucast_eq ucast_down_wi)
 
 lemma scast_scast_b:
   "\<lbrakk> is_up (scast :: 'a word \<Rightarrow> 'b word) \<rbrakk> \<Longrightarrow>
      (scast (scast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = scast a"
   by (metis scast_eq sint_up_scast)
 
 lemma ucast_scast_1:
   "\<lbrakk> is_down (scast :: 'a word \<Rightarrow> 'b word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
             (ucast (scast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = scast a"
   by (metis scast_eq ucast_down_wi)
 
 lemma ucast_scast_3:
   "\<lbrakk> is_down (scast :: 'a word \<Rightarrow> 'c word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
      (ucast (scast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = scast a"
   by (metis scast_eq ucast_down_wi)
 
 lemma ucast_scast_4:
   "\<lbrakk> is_up (scast :: 'a word \<Rightarrow> 'b word); is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
      (ucast (scast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = scast a"
   by (metis down_cast_same scast_eq sint_up_scast)
 
 lemma ucast_ucast_a:
   "\<lbrakk> is_down (ucast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
         (ucast (ucast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = ucast a"
   by (metis down_cast_same ucast_eq ucast_down_wi)
 
 lemma ucast_ucast_b:
   "\<lbrakk> is_up (ucast :: 'a word \<Rightarrow> 'b word) \<rbrakk> \<Longrightarrow>
      (ucast (ucast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = ucast a"
   by (metis ucast_up_ucast)
 
 lemma scast_scast_a:
   "\<lbrakk> is_down (scast :: 'b word \<Rightarrow> 'c word) \<rbrakk> \<Longrightarrow>
             (scast (scast (a :: 'a::len word) :: 'b::len word) :: 'c::len word) = scast a"
   apply (simp only: scast_eq)
   apply (metis down_cast_same is_up_down scast_eq ucast_down_wi)
   done
 
 lemma scast_down_wi [OF refl]:
   "uc = scast \<Longrightarrow> is_down uc \<Longrightarrow> uc (word_of_int x) = word_of_int x"
   by (metis down_cast_same is_up_down ucast_down_wi)
 
 lemmas cast_simps =
   is_down is_up
   scast_down_add scast_down_minus scast_down_mult
   ucast_down_add ucast_down_minus ucast_down_mult
   scast_ucast_1 scast_ucast_3 scast_ucast_4
   ucast_scast_1 ucast_scast_3 ucast_scast_4
   ucast_ucast_a ucast_ucast_b
   scast_scast_a scast_scast_b
   ucast_down_bl
   ucast_down_wi scast_down_wi
   ucast_of_nat scast_of_nat
   uint_up_ucast sint_up_scast
   up_scast_surj up_ucast_surj
 
 lemma smod_mod_positive:
     "\<lbrakk> 0 \<le> (a :: int); 0 \<le> b \<rbrakk> \<Longrightarrow> a smod b = a mod b"
   by (clarsimp simp: smod_int_alt_def zsgn_def)
 
 lemma nat_mult_power_less_eq:
   "b > 0 \<Longrightarrow> (a * b ^ n < (b :: nat) ^ m) = (a < b ^ (m - n))"
   using mult_less_cancel2[where m = a and k = "b ^ n" and n="b ^ (m - n)"]
         mult_less_cancel2[where m="a * b ^ (n - m)" and k="b ^ m" and n=1]
   apply (simp only: power_add[symmetric] nat_minus_add_max)
   apply (simp only: power_add[symmetric] nat_minus_add_max ac_simps)
   apply (simp add: max_def split: if_split_asm)
   done
 
 lemma signed_shift_guard_to_word:
   "\<lbrakk> n < len_of TYPE ('a); n > 0 \<rbrakk>
     \<Longrightarrow> (unat (x :: 'a :: len word) * 2 ^ y < 2 ^ n)
     = (x = 0 \<or> x < (1 << n >> y))"
   apply (simp only: nat_mult_power_less_eq)
   apply (cases "y \<le> n")
    apply (simp only: shiftl_shiftr1)
    apply (subst less_mask_eq)
     apply (simp add: word_less_nat_alt word_size)
     apply (rule order_less_le_trans[rotated], rule power_increasing[where n=1])
       apply simp
      apply simp
     apply simp
    apply (simp add: nat_mult_power_less_eq word_less_nat_alt word_size)
    apply auto[1]
   apply (simp only: shiftl_shiftr2, simp add: unat_eq_0)
   done
 
 lemma sint_ucast_eq_uint:
     "\<lbrakk> \<not> is_down (ucast :: ('a::len word \<Rightarrow> 'b::len word)) \<rbrakk>
             \<Longrightarrow> sint ((ucast :: ('a::len word \<Rightarrow> 'b::len word)) x) = uint x"
   apply (subst sint_eq_uint)
-   apply (clarsimp simp: msb_nth nth_ucast is_down)
-   apply (metis Suc_leI Suc_pred len_gt_0)
-  apply (clarsimp simp: uint_up_ucast is_up is_down)
+   apply (simp add: msb_word_eq)
+   apply transfer
+   apply (simp add: bit_take_bit_iff)
+  apply transfer
+  apply simp
   done
 
 lemma word_less_nowrapI':
   "(x :: 'a :: len word) \<le> z - k \<Longrightarrow> k \<le> z \<Longrightarrow> 0 < k \<Longrightarrow> x < x + k"
   by uint_arith
 
 lemma mask_plus_1:
   "mask n + 1 = (2 ^ n :: 'a::len word)"
   by (clarsimp simp: mask_eq_decr_exp)
 
 lemma unat_inj: "inj unat"
   by (metis eq_iff injI word_le_nat_alt)
 
 lemma unat_ucast_upcast:
   "is_up (ucast :: 'b word \<Rightarrow> 'a word)
       \<Longrightarrow> unat (ucast x :: ('a::len) word) = unat (x :: ('b::len) word)"
   unfolding ucast_eq unat_eq_nat_uint
   apply (subst int_word_uint)
   apply (subst mod_pos_pos_trivial)
     apply simp
    apply (rule lt2p_lem)
    apply (clarsimp simp: is_up)
   apply simp
   done
 
 lemma ucast_mono:
   "\<lbrakk> (x :: 'b :: len word) < y; y < 2 ^ LENGTH('a) \<rbrakk>
    \<Longrightarrow> ucast x < ((ucast y) :: 'a :: len word)"
   apply (simp only: flip: ucast_nat_def)
   apply (rule of_nat_mono_maybe)
   apply (rule unat_less_helper)
   apply (simp add: Power.of_nat_power)
   apply (simp add: word_less_nat_alt)
   done
 
 lemma ucast_mono_le:
   "\<lbrakk>x \<le> y; y < 2 ^ LENGTH('b)\<rbrakk> \<Longrightarrow> (ucast (x :: 'a :: len word) :: 'b :: len word) \<le> ucast y"
   apply (simp only: flip: ucast_nat_def)
   apply (subst of_nat_mono_maybe_le[symmetric])
     apply (rule unat_less_helper)
     apply (simp add: Power.of_nat_power)
    apply (rule unat_less_helper)
    apply (erule le_less_trans)
    apply (simp add: Power.of_nat_power)
   apply (simp add: word_le_nat_alt)
   done
 
 lemma ucast_mono_le':
   "\<lbrakk> unat y < 2 ^ LENGTH('b); LENGTH('b::len) < LENGTH('a::len); x \<le> y \<rbrakk>
    \<Longrightarrow> UCAST('a \<rightarrow> 'b) x \<le> UCAST('a \<rightarrow> 'b) y"
   by (auto simp: word_less_nat_alt intro: ucast_mono_le)
 
 lemma zero_sle_ucast_up:
   "\<not> is_down (ucast :: 'a word \<Rightarrow> 'b signed word) \<Longrightarrow>
           (0 <=s ((ucast (b::('a::len) word)) :: ('b::len) signed word))"
   apply (subgoal_tac "\<not> msb (ucast b :: 'b signed word)")
    apply (clarsimp simp: word_sle_msb_le)
   apply (clarsimp simp: is_down not_le msb_nth nth_ucast)
-  apply (subst (asm) test_bit_conj_lt [symmetric])
-  apply clarsimp
-  apply arith
   done
 
 lemma word_le_ucast_sless:
   "\<lbrakk> x \<le> y; y \<noteq> -1; LENGTH('a) < LENGTH('b) \<rbrakk> \<Longrightarrow>
     UCAST (('a :: len) \<rightarrow> ('b :: len) signed) x <s ucast (y + 1)"
   by (clarsimp simp: word_le_make_less word_sless_alt sint_ucast_eq_uint is_down word_less_def)
 
 lemma msb_ucast_eq:
     "LENGTH('a) = LENGTH('b) \<Longrightarrow>
          msb (ucast x :: ('a::len) word) = msb (x :: ('b::len) word)"
   apply (clarsimp simp: word_msb_alt)
   apply (subst ucast_down_drop [where n=0])
    apply (clarsimp simp: source_size_def target_size_def word_size)
   apply clarsimp
   done
 
 lemma msb_big:
      "msb (a :: ('a::len) word) = (a \<ge> 2 ^ (LENGTH('a)  - Suc 0))"
   apply (rule iffI)
    apply (clarsimp simp: msb_nth)
    apply (drule bang_is_le)
    apply simp
   apply (rule ccontr)
   apply (subgoal_tac "a = a && mask (LENGTH('a) - Suc 0)")
    apply (cut_tac and_mask_less' [where w=a and n="LENGTH('a) - Suc 0"])
     apply (clarsimp simp: word_not_le [symmetric])
    apply clarsimp
   apply (rule sym, subst and_mask_eq_iff_shiftr_0)
   apply (clarsimp simp: msb_shift)
   done
 
 lemma zero_sle_ucast:
   "(0 <=s ((ucast (b::('a::len) word)) :: ('a::len) signed word))
                 = (uint b < 2 ^ (LENGTH('a) - 1))"
   apply (case_tac "msb b")
    apply (clarsimp simp: word_sle_msb_le not_less msb_ucast_eq del: notI)
    apply (clarsimp simp: msb_big word_le_def uint_2p_alt)
   apply (clarsimp simp: word_sle_msb_le not_less msb_ucast_eq del: notI)
   apply (clarsimp simp: msb_big word_le_def uint_2p_alt)
   done
 
 
 (* to_bool / from_bool. *)
 
 definition
   from_bool :: "bool \<Rightarrow> 'a::len word" where
   "from_bool b \<equiv> case b of True \<Rightarrow> of_nat 1
                          | False \<Rightarrow> of_nat 0"
 
 lemma from_bool_eq:
   \<open>from_bool = of_bool\<close>
   by (simp add: fun_eq_iff from_bool_def)
 
 lemma from_bool_0:
   "(from_bool x = 0) = (\<not> x)"
   by (simp add: from_bool_def split: bool.split)
 
 definition
   to_bool :: "'a::len word \<Rightarrow> bool" where
   "to_bool \<equiv> (\<noteq>) 0"
 
 lemma to_bool_and_1:
   "to_bool (x && 1) = (x !! 0)"
   by (simp add: test_bit_word_eq to_bool_def and_one_eq mod_2_eq_odd)
 
 lemma to_bool_from_bool [simp]:
   "to_bool (from_bool r) = r"
   unfolding from_bool_def to_bool_def
   by (simp split: bool.splits)
 
 lemma from_bool_neq_0 [simp]:
   "(from_bool b \<noteq> 0) = b"
   by (simp add: from_bool_def split: bool.splits)
 
 lemma from_bool_mask_simp [simp]:
   "(from_bool r :: 'a::len word) && 1 = from_bool r"
   unfolding from_bool_def
   by (clarsimp split: bool.splits)
 
 lemma from_bool_1 [simp]:
   "(from_bool P = 1) = P"
   by (simp add: from_bool_def split: bool.splits)
 
 lemma ge_0_from_bool [simp]:
   "(0 < from_bool P) = P"
   by (simp add: from_bool_def split: bool.splits)
 
 lemma limited_and_from_bool:
   "limited_and (from_bool b) 1"
   by (simp add: from_bool_def limited_and_def split: bool.split)
 
 lemma to_bool_1 [simp]: "to_bool 1" by (simp add: to_bool_def)
 lemma to_bool_0 [simp]: "\<not>to_bool 0" by (simp add: to_bool_def)
 
 lemma from_bool_eq_if:
   "(from_bool Q = (if P then 1 else 0)) = (P = Q)"
   by (simp add: case_bool_If from_bool_def split: if_split)
 
 lemma to_bool_eq_0:
   "(\<not> to_bool x) = (x = 0)"
   by (simp add: to_bool_def)
 
 lemma to_bool_neq_0:
   "(to_bool x) = (x \<noteq> 0)"
   by (simp add: to_bool_def)
 
 lemma from_bool_all_helper:
   "(\<forall>bool. from_bool bool = val \<longrightarrow> P bool)
       = ((\<exists>bool. from_bool bool = val) \<longrightarrow> P (val \<noteq> 0))"
   by (auto simp: from_bool_0)
 
 lemma from_bool_to_bool_iff:
   "w = from_bool b \<longleftrightarrow> to_bool w = b \<and> (w = 0 \<or> w = 1)"
   by (cases b) (auto simp: from_bool_def to_bool_def)
 
 lemma from_bool_eqI:
   "from_bool x = from_bool y \<Longrightarrow> x = y"
   unfolding from_bool_def
   by (auto split: bool.splits)
 
 lemma word_rsplit_upt:
   "\<lbrakk> size x = LENGTH('a :: len) * n; n \<noteq> 0 \<rbrakk>
     \<Longrightarrow> word_rsplit x = map (\<lambda>i. ucast (x >> i * len_of TYPE ('a)) :: 'a word) (rev [0 ..< n])"
   apply (subgoal_tac "length (word_rsplit x :: 'a word list) = n")
    apply (rule nth_equalityI, simp)
    apply (intro allI word_eqI impI)
    apply (simp add: test_bit_rsplit_alt word_size)
    apply (simp add: nth_ucast nth_shiftr rev_nth field_simps)
   apply (simp add: length_word_rsplit_exp_size)
   apply (metis mult.commute given_quot_alt word_size word_size_gt_0)
   done
 
 lemma aligned_shift:
   "\<lbrakk>x < 2 ^ n; is_aligned (y :: 'a :: len word) n;n \<le> LENGTH('a)\<rbrakk>
    \<Longrightarrow> x + y >> n = y >> n"
   by (subst word_plus_and_or_coroll; word_eqI, blast)
 
 lemma aligned_shift':
   "\<lbrakk>x < 2 ^ n; is_aligned (y :: 'a :: len word) n;n \<le> LENGTH('a)\<rbrakk>
    \<Longrightarrow> y + x >> n = y >> n"
   by (subst word_plus_and_or_coroll; word_eqI, blast)
 
 lemma neg_mask_add_mask:
   "((x:: 'a :: len word) && ~~ (mask n)) + (2 ^ n - 1) = x || mask n"
   unfolding mask_2pm1[symmetric]
   by (subst word_plus_and_or_coroll; word_eqI_solve)
 
 lemma subtract_mask:
   "p - (p && mask n) = (p && ~~ (mask n))"
   "p - (p && ~~ (mask n)) = (p && mask n)"
   by (simp add: field_simps word_plus_and_or_coroll2)+
 
 lemma and_neg_mask_plus_mask_mono: "(p && ~~ (mask n)) + mask n \<ge> p"
   apply (rule word_le_minus_cancel[where x = "p && ~~ (mask n)"])
    apply (clarsimp simp: subtract_mask)
    using word_and_le1[where a = "mask n" and y = p]
    apply (clarsimp simp: mask_eq_decr_exp word_le_less_eq)
   apply (rule is_aligned_no_overflow'[folded mask_2pm1])
   apply (clarsimp simp: is_aligned_neg_mask)
   done
 
 lemma word_neg_and_le:
   "ptr \<le> (ptr && ~~ (mask n)) + (2 ^ n - 1)"
   by (simp add: and_neg_mask_plus_mask_mono mask_2pm1[symmetric])
 
 lemma aligned_less_plus_1:
   "\<lbrakk> is_aligned x n; n > 0 \<rbrakk> \<Longrightarrow> x < x + 1"
   apply (rule plus_one_helper2)
    apply (rule order_refl)
   apply (clarsimp simp: field_simps)
   apply (drule arg_cong[where f="\<lambda>x. x - 1"])
   apply (clarsimp simp: is_aligned_mask)
   apply (drule word_eqD[where x=0])
   apply simp
   done
 
 lemma aligned_add_offset_less:
   "\<lbrakk>is_aligned x n; is_aligned y n; x < y; z < 2 ^ n\<rbrakk> \<Longrightarrow> x + z < y"
   apply (cases "y = 0")
    apply simp
   apply (erule is_aligned_get_word_bits[where p=y], simp_all)
   apply (cases "z = 0", simp_all)
   apply (drule(2) aligned_at_least_t2n_diff[rotated -1])
   apply (drule plus_one_helper2)
    apply (rule less_is_non_zero_p1)
    apply (rule aligned_less_plus_1)
     apply (erule aligned_sub_aligned[OF _ _ order_refl],
            simp_all add: is_aligned_triv)[1]
    apply (cases n, simp_all)[1]
   apply (simp only: trans[OF diff_add_eq diff_diff_eq2[symmetric]])
   apply (drule word_less_add_right)
    apply (rule ccontr, simp add: linorder_not_le)
    apply (drule aligned_small_is_0, erule order_less_trans)
     apply (clarsimp simp: power_overflow)
    apply simp
   apply (erule order_le_less_trans[rotated],
          rule word_plus_mono_right)
    apply (erule word_le_minus_one_leq)
   apply (simp add: is_aligned_no_wrap' is_aligned_no_overflow field_simps)
   done
 
 lemma is_aligned_add_helper:
   "\<lbrakk> is_aligned p n; d < 2 ^ n \<rbrakk>
      \<Longrightarrow> (p + d && mask n = d) \<and> (p + d && (~~ (mask n)) = p)"
   apply (subst(asm) is_aligned_mask)
   apply (drule less_mask_eq)
   apply (rule context_conjI)
    apply (subst word_plus_and_or_coroll; word_eqI; blast)
   using word_plus_and_or_coroll2[where x="p + d" and w="mask n"] by simp
 
 lemma is_aligned_sub_helper:
   "\<lbrakk> is_aligned (p - d) n; d < 2 ^ n \<rbrakk>
      \<Longrightarrow> (p && mask n = d) \<and> (p && (~~ (mask n)) = p - d)"
   by (drule(1) is_aligned_add_helper, simp)
 
 lemma mask_twice:
   "(x && mask n) && mask m = x && mask (min m n)"
   by word_eqI_solve
 
 lemma is_aligned_after_mask:
   "\<lbrakk>is_aligned k m;m\<le> n\<rbrakk> \<Longrightarrow> is_aligned (k && mask n) m"
   by (rule is_aligned_andI1)
 
 lemma and_mask_plus:
   "\<lbrakk>is_aligned ptr m; m \<le> n; a < 2 ^ m\<rbrakk>
    \<Longrightarrow> ptr + a && mask n = (ptr && mask n) + a"
   apply (rule mask_eqI[where n = m])
    apply (simp add:mask_twice min_def)
     apply (simp add:is_aligned_add_helper)
     apply (subst is_aligned_add_helper[THEN conjunct1])
       apply (erule is_aligned_after_mask)
      apply simp
     apply simp
    apply simp
   apply (subgoal_tac "(ptr + a && mask n) && ~~ (mask m)
      = (ptr + a && ~~ (mask m) ) && mask n")
    apply (simp add:is_aligned_add_helper)
    apply (subst is_aligned_add_helper[THEN conjunct2])
      apply (simp add:is_aligned_after_mask)
     apply simp
    apply simp
   apply (simp add:word_bw_comms word_bw_lcs)
   done
 
 lemma le_step_down_word:"\<lbrakk>(i::('a::len) word) \<le> n; i = n \<longrightarrow> P; i \<le> n - 1 \<longrightarrow> P\<rbrakk> \<Longrightarrow> P"
   by unat_arith
 
 lemma le_step_down_word_2:
   fixes x :: "'a::len word"
   shows "\<lbrakk>x \<le>  y; x \<noteq> y\<rbrakk> \<Longrightarrow> x \<le> y - 1"
   by (subst (asm) word_le_less_eq,
       clarsimp,
       simp add: word_le_minus_one_leq)
 
 lemma NOT_mask_AND_mask[simp]: "(w && mask n) && ~~ (mask n) = 0"
   by (clarsimp simp add: mask_eq_decr_exp Parity.bit_eq_iff bit_and_iff bit_not_iff bit_mask_iff)
 
 lemma and_and_not[simp]:"(a && b) && ~~ b = 0"
   apply (subst word_bw_assocs(1))
   apply clarsimp
   done
 
 lemma mask_shift_and_negate[simp]:"(w && mask n << m) && ~~ (mask n << m) = 0"
   by (clarsimp simp add: mask_eq_decr_exp Parity.bit_eq_iff bit_and_iff bit_not_iff shiftl_word_eq bit_push_bit_iff)
 
 lemma le_step_down_nat:"\<lbrakk>(i::nat) \<le> n; i = n \<longrightarrow> P; i \<le> n - 1 \<longrightarrow> P\<rbrakk> \<Longrightarrow> P"
   by arith
 
 lemma le_step_down_int:"\<lbrakk>(i::int) \<le> n; i = n \<longrightarrow> P; i \<le> n - 1 \<longrightarrow> P\<rbrakk> \<Longrightarrow> P"
   by arith
 
 lemma ex_mask_1[simp]: "(\<exists>x. mask x = (1 :: 'a::len word))"
   apply (rule_tac x=1 in exI)
   apply (simp add:mask_eq_decr_exp)
   done
 
 lemma not_switch:"~~ a = x \<Longrightarrow> a = ~~ x"
   by auto
 
 (* The seL4 bitfield generator produces functions containing mask and shift operations, such that
  * invoking two of them consecutively can produce something like the following.
  *)
 lemma bitfield_op_twice:
   "(x && ~~ (mask n << m) || ((y && mask n) << m)) && ~~ (mask n << m) = x && ~~ (mask n << m)"
   by (induct n arbitrary: m) (auto simp: word_ao_dist)
 
 lemma bitfield_op_twice'':
   "\<lbrakk>~~ a = b << c; \<exists>x. b = mask x\<rbrakk> \<Longrightarrow> (x && a || (y && b << c)) && a = x && a"
   apply clarsimp
   apply (cut_tac n=xa and m=c and x=x and y=y in bitfield_op_twice)
   apply (clarsimp simp:mask_eq_decr_exp)
   apply (drule not_switch)
   apply clarsimp
   done
 
 lemma bit_twiddle_min:
   "(y::'a::len word) xor (((x::'a::len word) xor y) && (if x < y then -1 else 0)) = min x y"
   by (auto simp add: Parity.bit_eq_iff bit_xor_iff min_def)
 
 lemma bit_twiddle_max:
   "(x::'a::len word) xor (((x::'a::len word) xor y) && (if x < y then -1 else 0)) = max x y"
   by (auto simp add: Parity.bit_eq_iff bit_xor_iff max_def)
 
 lemma swap_with_xor:
   "\<lbrakk>(x::'a::len word) = a xor b; y = b xor x; z = x xor y\<rbrakk> \<Longrightarrow> z = b \<and> y = a"
   by (auto simp add: Parity.bit_eq_iff bit_xor_iff max_def)
 
 lemma scast_nop1 [simp]:
   "((scast ((of_int x)::('a::len) word))::'a sword) = of_int x"
   apply (simp only: scast_eq)
   by (metis len_signed sint_sbintrunc' word_sint.Rep_inverse)
 
 lemma scast_nop2 [simp]:
   "((scast ((of_int x)::('a::len) sword))::'a word) = of_int x"
   apply (simp only: scast_eq)
   by (metis len_signed sint_sbintrunc' word_sint.Rep_inverse)
 
 lemmas scast_nop = scast_nop1 scast_nop2 scast_id
 
 lemma le_mask_imp_and_mask:
   "(x::'a::len word) \<le> mask n \<Longrightarrow> x && mask n = x"
   by (metis and_mask_eq_iff_le_mask)
 
 lemma or_not_mask_nop:
   "((x::'a::len word) || ~~ (mask n)) && mask n = x && mask n"
   by (metis word_and_not word_ao_dist2 word_bw_comms(1) word_log_esimps(3))
 
 lemma mask_subsume:
   "\<lbrakk>n \<le> m\<rbrakk> \<Longrightarrow> ((x::'a::len word) || y && mask n) && ~~ (mask m) = x && ~~ (mask m)"
   by (auto simp add: Parity.bit_eq_iff bit_not_iff bit_or_iff bit_and_iff bit_mask_iff)
 
 lemma and_mask_0_iff_le_mask:
   fixes w :: "'a::len word"
   shows "(w && ~~(mask n) = 0) = (w \<le> mask n)"
   by (simp add: mask_eq_0_eq_x le_mask_imp_and_mask and_mask_eq_iff_le_mask)
 
 lemma mask_twice2:
   "n \<le> m \<Longrightarrow> ((x::'a::len word) && mask m) && mask n = x && mask n"
   by (metis mask_twice min_def)
 
 lemma uint_2_id:
   "LENGTH('a) \<ge> 2 \<Longrightarrow> uint (2::('a::len) word) = 2"
   by simp
 
 lemma bintrunc_id:
   "\<lbrakk>m \<le> of_nat n; 0 < m\<rbrakk> \<Longrightarrow> bintrunc n m = m"
   by (simp add: bintrunc_mod2p le_less_trans)
 
 lemma shiftr1_unfold: "shiftr1 x = x >> 1"
   by (metis One_nat_def comp_apply funpow.simps(1) funpow.simps(2) id_apply shiftr_def)
 
 lemma shiftr1_is_div_2: "(x::('a::len) word) >> 1 = x div 2"
   by transfer (simp add: drop_bit_Suc)
 
 lemma shiftl1_is_mult: "(x << 1) = (x :: 'a::len word) * 2"
   by (metis One_nat_def mult_2 mult_2_right one_add_one
         power_0 power_Suc shiftl_t2n)
 
 lemma div_of_0_id[simp]:"(0::('a::len) word) div n = 0"
   by (simp add: word_div_def)
 
 lemma degenerate_word:"LENGTH('a) = 1 \<Longrightarrow> (x::('a::len) word) = 0 \<or> x = 1"
   by (metis One_nat_def less_irrefl_nat sint_1_cases)
 
 lemma div_by_0_word:"(x::('a::len) word) div 0 = 0"
   by (metis div_0 div_by_0 unat_0 word_arith_nat_defs(6) word_div_1)
 
 lemma div_less_dividend_word:"\<lbrakk>x \<noteq> 0; n \<noteq> 1\<rbrakk> \<Longrightarrow> (x::('a::len) word) div n < x"
   apply (cases \<open>n = 0\<close>)
    apply clarsimp
    apply (simp add:word_neq_0_conv)
   apply (subst word_arith_nat_div)
   apply (rule word_of_nat_less)
   apply (rule div_less_dividend)
   using unat_eq_zero word_unat_Rep_inject1 apply force
   apply (simp add:unat_gt_0)
   done
 
 lemma shiftr1_lt:"x \<noteq> 0 \<Longrightarrow> (x::('a::len) word) >> 1 < x"
   apply (subst shiftr1_is_div_2)
   apply (rule div_less_dividend_word)
    apply simp+
   done
 
 lemma word_less_div:
   fixes x :: "('a::len) word"
     and y :: "('a::len) word"
   shows "x div y = 0 \<Longrightarrow> y = 0 \<or> x < y"
   apply (case_tac "y = 0", clarsimp+)
   by (metis One_nat_def Suc_le_mono le0 le_div_geq not_less unat_0 unat_div unat_gt_0 word_less_nat_alt zero_less_one)
 
 lemma not_degenerate_imp_2_neq_0:"LENGTH('a) > 1 \<Longrightarrow> (2::('a::len) word) \<noteq> 0"
   by (metis numerals(1) power_not_zero power_zero_numeral)
 
 lemma shiftr1_0_or_1:"(x::('a::len) word) >> 1 = 0 \<Longrightarrow> x = 0 \<or> x = 1"
   apply (subst (asm) shiftr1_is_div_2)
   apply (drule word_less_div)
   apply (case_tac "LENGTH('a) = 1")
    apply (simp add:degenerate_word)
   apply (erule disjE)
    apply (subgoal_tac "(2::'a word) \<noteq> 0")
     apply simp
    apply (rule not_degenerate_imp_2_neq_0)
    apply (subgoal_tac "LENGTH('a) \<noteq> 0")
     apply arith
    apply simp
   apply (rule x_less_2_0_1', simp+)
   done
 
 lemma word_overflow:"(x::('a::len) word) + 1 > x \<or> x + 1 = 0"
   apply clarsimp
   by (metis diff_0 eq_diff_eq less_x_plus_1)
 
 lemma word_overflow_unat:"unat ((x::('a::len) word) + 1) = unat x + 1 \<or> x + 1 = 0"
   by (metis Suc_eq_plus1 add.commute unatSuc)
 
 lemma even_word_imp_odd_next:"even (unat (x::('a::len) word)) \<Longrightarrow> x + 1 = 0 \<or> odd (unat (x + 1))"
   apply (cut_tac x=x in word_overflow_unat)
   apply clarsimp
   done
 
 lemma odd_word_imp_even_next:"odd (unat (x::('a::len) word)) \<Longrightarrow> x + 1 = 0 \<or> even (unat (x + 1))"
   apply (cut_tac x=x in word_overflow_unat)
   apply clarsimp
   done
 
 lemma overflow_imp_lsb:"(x::('a::len) word) + 1 = 0 \<Longrightarrow> x !! 0"
   using even_plus_one_iff [of x] by (simp add: test_bit_word_eq)
 
 lemma word_lsb_nat:"lsb w = (unat w mod 2 = 1)"
   apply (simp add: word_lsb_def Groebner_Basis.algebra(31))
   apply transfer
   apply (simp add: even_nat_iff)
   done
 
 lemma odd_iff_lsb:"odd (unat (x::('a::len) word)) = x !! 0"
   apply (simp add:even_iff_mod_2_eq_zero)
   apply (subst word_lsb_nat[unfolded One_nat_def, symmetric])
   apply (rule word_lsb_alt)
   done
 
 lemma of_nat_neq_iff_word:
       "x mod 2 ^ LENGTH('a) \<noteq> y mod 2 ^ LENGTH('a) \<Longrightarrow>
          (((of_nat x)::('a::len) word) \<noteq> of_nat y) = (x \<noteq> y)"
   apply (rule iffI)
    apply (case_tac "x = y")
    apply (subst (asm) of_nat_eq_iff[symmetric])
    apply simp+
   apply (case_tac "((of_nat x)::('a::len) word) = of_nat y")
    apply (subst (asm) word_unat.norm_eq_iff[symmetric])
    apply simp+
   done
 
 lemma shiftr1_irrelevant_lsb:"(x::('a::len) word) !! 0 \<or> x >> 1 = (x + 1) >> 1"
   using word_overflow_unat [of x]
   apply (simp only: shiftr1_is_div_2 flip: odd_iff_lsb)
   apply (cases \<open>2 \<le> LENGTH('a)\<close>)
    apply (auto simp add: test_bit_def' word_arith_nat_div dest: overflow_imp_lsb)
   using odd_iff_lsb overflow_imp_lsb by blast
 
 lemma shiftr1_0_imp_only_lsb:"((x::('a::len) word) + 1) >> 1 = 0 \<Longrightarrow> x = 0 \<or> x + 1 = 0"
   by (metis One_nat_def shiftr1_0_or_1 word_less_1 word_overflow)
 
 lemma shiftr1_irrelevant_lsb':"\<not>((x::('a::len) word) !! 0) \<Longrightarrow> x >> 1 = (x + 1) >> 1"
   by (metis shiftr1_irrelevant_lsb)
 
 lemma lsb_this_or_next:"\<not>(((x::('a::len) word) + 1) !! 0) \<Longrightarrow> x !! 0"
   by (metis (poly_guards_query) even_word_imp_odd_next odd_iff_lsb overflow_imp_lsb)
 
 (* Perhaps this one should be a simp lemma, but it seems a little dangerous. *)
 lemma cast_chunk_assemble_id:
   "\<lbrakk>n = LENGTH('a::len); m = LENGTH('b::len); n * 2 = m\<rbrakk> \<Longrightarrow>
   (((ucast ((ucast (x::'b word))::'a word))::'b word) || (((ucast ((ucast (x >> n))::'a word))::'b word) << n)) = x"
   apply (subgoal_tac "((ucast ((ucast (x >> n))::'a word))::'b word) = x >> n")
    apply clarsimp
    apply (subst and_not_mask[symmetric])
    apply (subst ucast_ucast_mask)
    apply (subst word_ao_dist2[symmetric])
    apply clarsimp
   apply (rule ucast_ucast_len)
   apply (rule shiftr_less_t2n')
    apply (subst and_mask_eq_iff_le_mask)
    apply (simp_all add: mask_eq_decr_exp flip: mult_2_right)
   apply (metis add_diff_cancel_left' len_gt_0 mult_2_right zero_less_diff)
   done
 
 lemma cast_chunk_scast_assemble_id:
   "\<lbrakk>n = LENGTH('a::len); m = LENGTH('b::len); n * 2 = m\<rbrakk> \<Longrightarrow>
   (((ucast ((scast (x::'b word))::'a word))::'b word) ||
    (((ucast ((scast (x >> n))::'a word))::'b word) << n)) = x"
   apply (subgoal_tac "((scast x)::'a word) = ((ucast x)::'a word)")
    apply (subgoal_tac "((scast (x >> n))::'a word) = ((ucast (x >> n))::'a word)")
     apply (simp add:cast_chunk_assemble_id)
    apply (subst down_cast_same[symmetric], subst is_down, arith, simp)+
   done
 
 lemma mask_or_not_mask:
   "x && mask n || x && ~~ (mask n) = x"
   apply (subst word_oa_dist, simp)
   apply (subst word_oa_dist2, simp)
   done
 
 lemma is_aligned_add_not_aligned:
   "\<lbrakk>is_aligned (p::'a::len word) n; \<not> is_aligned (q::'a::len word) n\<rbrakk> \<Longrightarrow> \<not> is_aligned (p + q) n"
   by (metis is_aligned_addD1)
 
 lemma word_gr0_conv_Suc: "(m::'a::len word) > 0 \<Longrightarrow> \<exists>n. m = n + 1"
   by (metis add.commute add_minus_cancel)
 
 lemma neg_mask_add_aligned:
   "\<lbrakk> is_aligned p n; q < 2 ^ n \<rbrakk> \<Longrightarrow> (p + q) && ~~ (mask n) = p && ~~ (mask n)"
   by (metis is_aligned_add_helper is_aligned_neg_mask_eq)
 
 lemma word_sless_sint_le:"x <s y \<Longrightarrow> sint x \<le> sint y - 1"
   by (metis word_sless_alt zle_diff1_eq)
 
 
 lemma upper_trivial:
   fixes x :: "'a::len word"
   shows "x \<noteq> 2 ^ LENGTH('a) - 1 \<Longrightarrow> x < 2 ^ LENGTH('a) - 1"
   by (simp add: less_le)
 
 lemma constraint_expand:
   fixes x :: "'a::len word"
   shows "x \<in> {y. lower \<le> y \<and> y \<le> upper} = (lower \<le> x \<and> x \<le> upper)"
   by (rule mem_Collect_eq)
 
 lemma card_map_elide:
   "card ((of_nat :: nat \<Rightarrow> 'a::len word) ` {0..<n}) = card {0..<n}"
     if "n \<le> CARD('a::len word)"
 proof -
   let ?of_nat = "of_nat :: nat \<Rightarrow> 'a word"
   from word_unat.Abs_inj_on
   have "inj_on ?of_nat {i. i < CARD('a word)}"
     by (simp add: unats_def card_word)
   moreover have "{0..<n} \<subseteq> {i. i < CARD('a word)}"
     using that by auto
   ultimately have "inj_on ?of_nat {0..<n}"
     by (rule inj_on_subset)
   then show ?thesis
     by (simp add: card_image)
 qed
 
 lemma card_map_elide2:
   "n \<le> CARD('a::len word) \<Longrightarrow> card ((of_nat::nat \<Rightarrow> 'a::len word) ` {0..<n}) = n"
   by (subst card_map_elide) clarsimp+
 
 lemma le_max_word_ucast_id:
   \<open>UCAST('b \<rightarrow> 'a) (UCAST('a \<rightarrow> 'b) x) = x\<close>
     if \<open>x \<le> UCAST('b::len \<rightarrow> 'a) (- 1)\<close>
     for x :: \<open>'a::len word\<close>
 proof -
   from that have a1: \<open>x \<le> word_of_int (uint (word_of_int (2 ^ LENGTH('b) - 1) :: 'b word))\<close>
     by simp
   have f2: "((\<exists>i ia. (0::int) \<le> i \<and> \<not> 0 \<le> i + - 1 * ia \<and> i mod ia \<noteq> i) \<or>
             \<not> (0::int) \<le> - 1 + 2 ^ LENGTH('b) \<or> (0::int) \<le> - 1 + 2 ^ LENGTH('b) + - 1 * 2 ^ LENGTH('b) \<or>
             (- (1::int) + 2 ^ LENGTH('b)) mod 2 ^ LENGTH('b) =
               - 1 + 2 ^ LENGTH('b)) = ((\<exists>i ia. (0::int) \<le> i \<and> \<not> 0 \<le> i + - 1 * ia \<and> i mod ia \<noteq> i) \<or>
             \<not> (1::int) \<le> 2 ^ LENGTH('b) \<or>
             2 ^ LENGTH('b) + - (1::int) * ((- 1 + 2 ^ LENGTH('b)) mod 2 ^ LENGTH('b)) = 1)"
     by force
   have f3: "\<forall>i ia. \<not> (0::int) \<le> i \<or> 0 \<le> i + - 1 * ia \<or> i mod ia = i"
     using mod_pos_pos_trivial by force
   have "(1::int) \<le> 2 ^ LENGTH('b)"
     by simp
   then have "2 ^ LENGTH('b) + - (1::int) * ((- 1 + 2 ^ LENGTH('b)) mod 2 ^ len_of TYPE ('b)) = 1"
     using f3 f2 by blast
   then have f4: "- (1::int) + 2 ^ LENGTH('b) = (- 1 + 2 ^ LENGTH('b)) mod 2 ^ LENGTH('b)"
     by linarith
   have f5: "x \<le> word_of_int (uint (word_of_int (- 1 + 2 ^ LENGTH('b))::'b word))"
     using a1 by force
   have f6: "2 ^ LENGTH('b) + - (1::int) = - 1 + 2 ^ LENGTH('b)"
     by force
   have f7: "- (1::int) * 1 = - 1"
     by auto
   have "\<forall>x0 x1. (x1::int) - x0 = x1 + - 1 * x0"
     by force
   then have "x \<le> 2 ^ LENGTH('b) - 1"
     using f7 f6 f5 f4 by (metis uint_word_of_int wi_homs(2) word_arith_wis(8) word_of_int_2p)
   then have \<open>uint x \<le> uint (2 ^ LENGTH('b) - (1 :: 'a word))\<close>
     by (simp add: word_le_def)
   then have \<open>uint x \<le> 2 ^ LENGTH('b) - 1\<close>
     by (simp add: uint_word_ariths)
       (metis \<open>1 \<le> 2 ^ LENGTH('b)\<close> \<open>uint x \<le> uint (2 ^ LENGTH('b) - 1)\<close> linorder_not_less lt2p_lem uint_1 uint_minus_simple_alt uint_power_lower word_le_def zle_diff1_eq)
   then show ?thesis
     apply (simp add: word_ubin.eq_norm bintrunc_mod2p unsigned_ucast_eq)
     by (metis \<open>x \<le> 2 ^ LENGTH('b) - 1\<close> le_def take_bit_word_eq_self ucast_ucast_len unsigned_take_bit_eq word_less_sub_le word_ubin.norm_Rep word_uint_eqI)
 qed
 
 lemma remdups_enum_upto:
   fixes s::"'a::len word"
   shows "remdups [s .e. e] = [s .e. e]"
   by simp
 
 lemma card_enum_upto:
   fixes s::"'a::len word"
   shows "card (set [s .e. e]) = Suc (unat e) - unat s"
   by (subst List.card_set) (simp add: remdups_enum_upto)
 
 lemma unat_mask:
   "unat (mask n :: 'a :: len word) = 2 ^ (min n (LENGTH('a))) - 1"
   apply (subst min.commute)
   apply (simp add: mask_eq_decr_exp not_less min_def  split: if_split_asm)
   apply (intro conjI impI)
    apply (simp add: unat_sub_if_size)
    apply (simp add: power_overflow word_size)
   apply (simp add: unat_sub_if_size)
   done
 
 lemma word_shiftr_lt:
   fixes w :: "'a::len word"
   shows "unat (w >> n) < (2 ^ (LENGTH('a) - n))"
   apply (subst shiftr_div_2n')
   by (metis nat_mod_lem nat_zero_less_power_iff power_mod_div
       word_unat.Rep_inverse word_unat.eq_norm zero_less_numeral)
 
 lemma complement_nth_w2p:
   shows "n' < LENGTH('a) \<Longrightarrow> (~~ (2 ^ n :: 'a::len word)) !! n' = (n' \<noteq> n)"
   by (fastforce simp: word_ops_nth_size word_size nth_w2p)
 
 lemma word_unat_and_lt:
   "unat x < n \<or> unat y < n \<Longrightarrow> unat (x && y) < n"
   by (meson le_less_trans word_and_le1 word_and_le2 word_le_nat_alt)
 
 lemma word_unat_mask_lt:
   "m \<le> size w \<Longrightarrow> unat ((w::'a::len word) && mask m) < 2 ^ m"
   by (rule word_unat_and_lt) (simp add: unat_mask word_size)
 
 lemma unat_shiftr_less_t2n:
   fixes x :: "'a :: len word"
   shows "unat x < 2 ^ (n + m) \<Longrightarrow> unat (x >> n) < 2 ^ m"
   by (simp add: shiftr_div_2n' power_add mult.commute td_gal_lt)
 
 lemma le_or_mask:
   "w \<le> w' \<Longrightarrow> w || mask x \<le> w' || mask x"
   by (metis neg_mask_add_mask add.commute le_word_or1 mask_2pm1 neg_mask_mono_le word_plus_mono_left)
 
 lemma le_shiftr1':
   "\<lbrakk> shiftr1 u \<le> shiftr1 v ; shiftr1 u \<noteq> shiftr1 v \<rbrakk> \<Longrightarrow> u \<le> v"
   apply transfer
   apply simp
   done
 
 lemma le_shiftr':
   "\<lbrakk> u >> n \<le> v >> n ; u >> n \<noteq> v >> n \<rbrakk> \<Longrightarrow> (u::'a::len word) \<le> v"
   apply (induct n; simp add: shiftr_def)
   apply (case_tac "(shiftr1 ^^ n) u = (shiftr1 ^^ n) v", simp)
   apply (fastforce dest: le_shiftr1')
   done
 
 lemma word_log2_nth_same:
   "w \<noteq> 0 \<Longrightarrow> w !! word_log2 w"
   unfolding word_log2_def
   using nth_length_takeWhile[where P=Not and xs="to_bl w"]
   apply (simp add: word_clz_def word_size to_bl_nth)
   apply (fastforce simp: linorder_not_less eq_zero_set_bl
                    dest: takeWhile_take_has_property)
   done
 
 lemma word_log2_nth_not_set:
   "\<lbrakk> word_log2 w < i ; i < size w \<rbrakk> \<Longrightarrow> \<not> w !! i"
   unfolding word_log2_def word_clz_def
   using takeWhile_take_has_property_nth[where P=Not and xs="to_bl w" and n="size w - Suc i"]
   by (fastforce simp add: to_bl_nth word_size)
 
 lemma word_log2_highest:
   assumes a: "w !! i"
   shows "i \<le> word_log2 w"
 proof -
   from a have "i < size w" by - (rule test_bit_size)
   with a show ?thesis
     by - (rule ccontr, simp add: word_log2_nth_not_set)
 qed
 
 lemma word_log2_max:
   "word_log2 w < size w"
   unfolding word_log2_def word_clz_def
   by simp
 
 lemma word_clz_0[simp]:
   "word_clz (0::'a::len word) = LENGTH('a)"
   unfolding word_clz_def
   by (simp add: takeWhile_replicate)
 
 lemma word_clz_minus_one[simp]:
   "word_clz (-1::'a::len word) = 0"
   unfolding word_clz_def
   by (simp add: takeWhile_replicate)
 
 lemma word_add_no_overflow:"(x::'a::len word) < max_word \<Longrightarrow> x < x + 1"
   using less_x_plus_1 order_less_le by blast
 
 lemma lt_plus_1_le_word:
   fixes x :: "'a::len word"
   assumes bound:"n < unat (maxBound::'a word)"
   shows "x < 1 + of_nat n = (x \<le> of_nat n)"
   by (metis add.commute bound max_word_max word_Suc_leq word_not_le word_of_nat_less)
 
 lemma unat_ucast_up_simp:
   fixes x :: "'a::len word"
   assumes "LENGTH('a) \<le> LENGTH('b)"
   shows "unat (ucast x :: 'b::len word) = unat x"
   unfolding ucast_eq unat_eq_nat_uint
   apply (subst int_word_uint)
   apply (subst mod_pos_pos_trivial; simp?)
   apply (rule lt2p_lem)
   apply (simp add: assms)
   done
 
 lemma unat_ucast_less_no_overflow:
   "\<lbrakk>n < 2 ^ LENGTH('a); unat f < n\<rbrakk> \<Longrightarrow> (f::('a::len) word) < of_nat n"
   by (erule (1)  order_le_less_trans[OF _ of_nat_mono_maybe,rotated]) simp
 
 lemma unat_ucast_less_no_overflow_simp:
   "n < 2 ^ LENGTH('a) \<Longrightarrow> (unat f < n) = ((f::('a::len) word) < of_nat n)"
   using unat_less_helper unat_ucast_less_no_overflow by blast
 
 lemma unat_ucast_no_overflow_le:
   assumes no_overflow: "unat b < (2 :: nat) ^ LENGTH('a)"
   and upward_cast: "LENGTH('a) < LENGTH('b)"
   shows "(ucast (f::'a::len word) < (b :: 'b :: len word)) = (unat f < unat b)"
 proof -
   have LR: "ucast f < b \<Longrightarrow> unat f < unat b"
     apply (rule unat_less_helper)
     apply (simp add:ucast_nat_def)
     apply (rule_tac 'b1 = 'b in  ucast_less_ucast[OF order.strict_implies_order, THEN iffD1])
      apply (rule upward_cast)
     apply (simp add: ucast_ucast_mask less_mask_eq word_less_nat_alt
                      unat_power_lower[OF upward_cast] no_overflow)
     done
   have RL: "unat f < unat b \<Longrightarrow> ucast f < b"
   proof-
     assume ineq: "unat f < unat b"
     have "ucast (f::'a::len word) < ((ucast (ucast b ::'a::len word)) :: 'b :: len word)"
       apply (simp add: ucast_less_ucast[OF order.strict_implies_order] upward_cast)
       apply (simp only: flip: ucast_nat_def)
       apply (rule unat_ucast_less_no_overflow[OF no_overflow ineq])
       done
     then show ?thesis
       apply (rule order_less_le_trans)
       apply (simp add:ucast_ucast_mask word_and_le2)
       done
   qed
   then show ?thesis by (simp add:RL LR iffI)
 qed
 
 lemmas ucast_up_mono = ucast_less_ucast[THEN iffD2]
 
 (* casting a long word to a shorter word and casting back to the long word
    is equal to the original long word -- if the word is small enough.
   'l is the longer word.
   's is the shorter word.
 *)
 lemma bl_cast_long_short_long_ingoreLeadingZero_generic:
   "\<lbrakk> length (dropWhile Not (to_bl w)) \<le> LENGTH('s); LENGTH('s) \<le> LENGTH('l) \<rbrakk> \<Longrightarrow>
    (of_bl :: _ \<Rightarrow> 'l::len word) (to_bl ((of_bl::_ \<Rightarrow> 's::len word) (to_bl w))) = w"
   by (rule word_uint_eqI) (simp add: uint_of_bl_is_bl_to_bin uint_of_bl_is_bl_to_bin_drop)
 
 (*
  Casting between longer and shorter word.
   'l is the longer word.
   's is the shorter word.
  For example: 'l::len word is 128 word (full ipv6 address)
               's::len word is 16 word (address piece of ipv6 address in colon-text-representation)
 *)
 corollary ucast_short_ucast_long_ingoreLeadingZero:
   "\<lbrakk> length (dropWhile Not (to_bl w)) \<le> LENGTH('s); LENGTH('s) \<le> LENGTH('l) \<rbrakk> \<Longrightarrow>
    (ucast:: 's::len word \<Rightarrow> 'l::len word) ((ucast:: 'l::len word \<Rightarrow> 's::len word) w) = w"
   apply (subst ucast_bl)+
   apply (rule bl_cast_long_short_long_ingoreLeadingZero_generic; simp)
   done
 
 lemma length_drop_mask:
   fixes w::"'a::len word"
   shows "length (dropWhile Not (to_bl (w AND mask n))) \<le> n"
 proof -
   have "length (takeWhile Not (replicate n False @ ls)) = n + length (takeWhile Not ls)"
     for ls n by(subst takeWhile_append2) simp+
   then show ?thesis
     unfolding bl_and_mask by (simp add: dropWhile_eq_drop)
 qed
 
 lemma minus_one_word:
   "(-1 :: 'a :: len word) = 2 ^ LENGTH('a) - 1"
   by simp
 
 lemma mask_exceed:
   "n \<ge> LENGTH('a) \<Longrightarrow> (x::'a::len word) && ~~ (mask n) = 0"
   by (simp add: and_not_mask shiftr_eq_0)
 
 lemma two_power_strict_part_mono:
   "strict_part_mono {..LENGTH('a) - 1} (\<lambda>x. (2 :: 'a :: len word) ^ x)"
 proof -
   { fix n
     have "n < LENGTH('a) \<Longrightarrow> strict_part_mono {..n} (\<lambda>x. (2 :: 'a :: len word) ^ x)"
     proof (induct n)
       case 0 then show ?case by simp
     next
       case (Suc n)
       from Suc.prems
       have "2 ^ n < (2 :: 'a :: len word) ^ Suc n"
         using power_strict_increasing unat_power_lower word_less_nat_alt by fastforce
       with Suc
       show ?case by (subst strict_part_mono_by_steps) simp
     qed
   }
   then show ?thesis by simp
 qed
 
 lemma word_shift_by_2:
   "x * 4 = (x::'a::len word) << 2"
   by (simp add: shiftl_t2n)
 
 lemma le_2p_upper_bits:
   "\<lbrakk> (p::'a::len word) \<le> 2^n - 1; n < LENGTH('a) \<rbrakk> \<Longrightarrow>
   \<forall>n'\<ge>n. n' < LENGTH('a) \<longrightarrow> \<not> p !! n'"
   by (subst upper_bits_unset_is_l2p; simp)
 
 lemma le2p_bits_unset:
   "p \<le> 2 ^ n - 1 \<Longrightarrow> \<forall>n'\<ge>n. n' < LENGTH('a) \<longrightarrow> \<not> (p::'a::len word) !! n'"
   using upper_bits_unset_is_l2p [where p=p]
   by (cases "n < LENGTH('a)") auto
 
 lemma ucast_less_shiftl_helper:
   "\<lbrakk> LENGTH('b) + 2 < LENGTH('a); 2 ^ (LENGTH('b) + 2) \<le> n\<rbrakk>
     \<Longrightarrow> (ucast (x :: 'b::len word) << 2) < (n :: 'a::len word)"
   apply (erule order_less_le_trans[rotated])
   using ucast_less[where x=x and 'a='a]
   apply (simp only: shiftl_t2n field_simps)
   apply (rule word_less_power_trans2; simp)
   done
 
 lemma word_power_nonzero:
   "\<lbrakk> (x :: 'a::len word) < 2 ^ (LENGTH('a) - n); n < LENGTH('a); x \<noteq> 0 \<rbrakk>
   \<Longrightarrow> x * 2 ^ n \<noteq> 0"
   by (metis and_mask_eq_iff_shiftr_0 less_mask_eq p2_gt_0 semiring_normalization_rules(7)
             shiftl_shiftr_id shiftl_t2n)
 
 lemma less_1_helper:
   "n \<le> m \<Longrightarrow> (n - 1 :: int) < m"
   by arith
 
 lemma div_power_helper:
   "\<lbrakk> x \<le> y; y < LENGTH('a) \<rbrakk> \<Longrightarrow> (2 ^ y - 1) div (2 ^ x :: 'a::len word) = 2 ^ (y - x) - 1"
   apply (rule word_uint.Rep_eqD)
   apply (simp only: uint_word_ariths uint_div uint_power_lower)
   apply (subst mod_pos_pos_trivial, fastforce, fastforce)+
   apply (subst mod_pos_pos_trivial)
     apply (simp add: le_diff_eq uint_2p_alt)
    apply (rule less_1_helper)
    apply (rule power_increasing; simp)
   apply (subst mod_pos_pos_trivial)
     apply (simp add: uint_2p_alt)
    apply (rule less_1_helper)
    apply (rule power_increasing; simp)
   apply (subst int_div_sub_1; simp add: uint_2p_alt)
   apply (subst power_0[symmetric])
   apply (simp add: uint_2p_alt le_imp_power_dvd power_sub_int)
   done
 
 
 lemma word_add_power_off:
   fixes a :: "'a :: len word"
   assumes ak: "a < k"
   and kw: "k < 2 ^ (LENGTH('a) - m)"
   and mw: "m < LENGTH('a)"
   and off: "off < 2 ^ m"
   shows "(a * 2 ^ m) + off < k * 2 ^ m"
 proof (cases "m = 0")
   case True
   then show ?thesis using off ak by simp
 next
   case False
 
   from ak have ak1: "a + 1 \<le> k" by (rule inc_le)
   then have "(a + 1) * 2 ^ m \<noteq> 0"
     apply -
     apply (rule word_power_nonzero)
     apply (erule order_le_less_trans  [OF _ kw])
     apply (rule mw)
     apply (rule less_is_non_zero_p1 [OF ak])
     done
   then have "(a * 2 ^ m) + off < ((a + 1) * 2 ^ m)" using kw mw
     apply -
     apply (simp add: distrib_right)
     apply (rule word_plus_strict_mono_right [OF off])
     apply (rule is_aligned_no_overflow'')
     apply (rule is_aligned_mult_triv2)
     apply assumption
     done
   also have "\<dots> \<le> k * 2 ^ m" using ak1 mw kw False
     apply -
     apply (erule word_mult_le_mono1)
     apply (simp add: p2_gt_0)
     apply (simp add: word_less_nat_alt)
     apply (rule nat_less_power_trans2[simplified])
     apply (simp add: word_less_nat_alt)
     apply simp
     done
   finally show ?thesis .
 qed
 
 lemma offset_not_aligned:
   "\<lbrakk> is_aligned (p::'a::len word) n; i > 0; i < 2 ^ n; n < LENGTH('a)\<rbrakk> \<Longrightarrow>
    \<not> is_aligned (p + of_nat i) n"
   apply (erule is_aligned_add_not_aligned)
   unfolding is_aligned_def
   by (metis le_unat_uoi nat_dvd_not_less order_less_imp_le unat_power_lower)
 
 lemma length_upto_enum_one:
   fixes x :: "'a :: len word"
   assumes lt1: "x < y" and lt2: "z < y" and lt3: "x \<le> z"
   shows "[x , y .e. z] = [x]"
   unfolding upto_enum_step_def
 proof (subst upto_enum_red, subst if_not_P [OF leD [OF lt3]], clarsimp, rule conjI)
   show "unat ((z - x) div (y - x)) = 0"
   proof (subst unat_div, rule div_less)
     have syx: "unat (y - x) = unat y - unat x"
       by (rule unat_sub [OF order_less_imp_le]) fact
     moreover have "unat (z - x) = unat z - unat x"
       by (rule unat_sub) fact
 
     ultimately show "unat (z - x) < unat (y - x)"
       using lt2 lt3 unat_mono word_less_minus_mono_left by blast
   qed
 
   then show "(z - x) div (y - x) * (y - x) = 0"
     by (metis mult_zero_left unat_0 word_unat.Rep_eqD)
 qed
 
 lemma max_word_mask:
   "(max_word :: 'a::len word) = mask LENGTH('a)"
   unfolding mask_eq_decr_exp by simp
 
 lemmas mask_len_max = max_word_mask[symmetric]
 
 lemma is_aligned_alignUp[simp]:
   "is_aligned (alignUp p n) n"
   by (simp add: alignUp_def complement_def is_aligned_mask mask_eq_decr_exp word_bw_assocs)
 
 lemma alignUp_le[simp]:
   "alignUp p n \<le> p + 2 ^ n - 1"
   unfolding alignUp_def by (rule word_and_le2)
 
 lemma complement_mask:
   "complement (2 ^ n - 1) = ~~ (mask n)"
   unfolding complement_def mask_eq_decr_exp by simp
 
 lemma alignUp_idem:
   fixes a :: "'a::len word"
   assumes "is_aligned a n" "n < LENGTH('a)"
   shows "alignUp a n = a"
   using assms unfolding alignUp_def
   by (metis complement_mask is_aligned_add_helper p_assoc_help power_2_ge_iff)
 
 lemma alignUp_not_aligned_eq:
   fixes a :: "'a :: len word"
   assumes al: "\<not> is_aligned a n"
   and     sz: "n < LENGTH('a)"
   shows   "alignUp a n = (a div 2 ^ n + 1) * 2 ^ n"
 proof -
   have anz: "a mod 2 ^ n \<noteq> 0"
     by (rule not_aligned_mod_nz) fact+
 
   then have um: "unat (a mod 2 ^ n - 1) div 2 ^ n = 0" using sz
     by (meson Euclidean_Division.div_eq_0_iff le_m1_iff_lt measure_unat order_less_trans
               unat_less_power word_less_sub_le word_mod_less_divisor)
 
   have "a + 2 ^ n - 1 = (a div 2 ^ n) * 2 ^ n + (a mod 2 ^ n) + 2 ^ n - 1"
     by (simp add: word_mod_div_equality)
   also have "\<dots> = (a mod 2 ^ n - 1) + (a div 2 ^ n + 1) * 2 ^ n"
     by (simp add: field_simps)
   finally show "alignUp a n = (a div 2 ^ n + 1) * 2 ^ n" using sz
     unfolding alignUp_def
     apply (subst complement_mask)
     apply (erule ssubst)
     apply (subst neg_mask_is_div)
     apply (simp add: word_arith_nat_div)
     apply (subst unat_word_ariths(1) unat_word_ariths(2))+
     apply (subst uno_simps)
     apply (subst unat_1)
     apply (subst mod_add_right_eq)
     apply simp
     apply (subst power_mod_div)
     apply (subst div_mult_self1)
      apply simp
     apply (subst um)
     apply simp
     apply (subst mod_mod_power)
     apply simp
     apply (subst word_unat_power, subst Abs_fnat_hom_mult)
     apply (subst mult_mod_left)
     apply (subst power_add [symmetric])
     apply simp
     apply (subst Abs_fnat_hom_1)
     apply (subst Abs_fnat_hom_add)
     apply (subst word_unat_power, subst Abs_fnat_hom_mult)
     apply (subst word_unat.Rep_inverse[symmetric], subst Abs_fnat_hom_mult)
     apply simp
     done
 qed
 
 lemma alignUp_ge:
   fixes a :: "'a :: len word"
   assumes sz: "n < LENGTH('a)"
   and nowrap: "alignUp a n \<noteq> 0"
   shows "a \<le> alignUp a n"
 proof (cases "is_aligned a n")
   case True
   then show ?thesis using sz
     by (subst alignUp_idem, simp_all)
 next
   case False
 
   have lt0: "unat a div 2 ^ n < 2 ^ (LENGTH('a) - n)" using sz
     by (metis shiftr_div_2n' word_shiftr_lt)
 
   have"2 ^ n * (unat a div 2 ^ n + 1) \<le> 2 ^ LENGTH('a)" using sz
     by (metis One_nat_def Suc_leI add.right_neutral add_Suc_right lt0 nat_le_power_trans nat_less_le)
   moreover have "2 ^ n * (unat a div 2 ^ n + 1) \<noteq> 2 ^ LENGTH('a)" using nowrap sz
     apply -
     apply (erule contrapos_nn)
     apply (subst alignUp_not_aligned_eq [OF False sz])
     apply (subst unat_arith_simps)
     apply (subst unat_word_ariths)
     apply (subst unat_word_ariths)
     apply simp
     apply (subst mult_mod_left)
     apply (simp add: unat_div field_simps power_add[symmetric] mod_mod_power min.absorb2)
     done
   ultimately have lt: "2 ^ n * (unat a div 2 ^ n + 1) < 2 ^ LENGTH('a)" by simp
 
   have "a = a div 2 ^ n * 2 ^ n + a mod 2 ^ n" by (rule word_mod_div_equality [symmetric])
   also have "\<dots> < (a div 2 ^ n + 1) * 2 ^ n" using sz lt
     apply (simp add: field_simps)
     apply (rule word_add_less_mono1)
     apply (rule word_mod_less_divisor)
     apply (simp add: word_less_nat_alt)
     apply (subst unat_word_ariths)
     apply (simp add: unat_div)
     done
   also have "\<dots> =  alignUp a n"
     by (rule alignUp_not_aligned_eq [symmetric]) fact+
   finally show ?thesis by (rule order_less_imp_le)
 qed
 
 lemma alignUp_le_greater_al:
   fixes x :: "'a :: len word"
   assumes le: "a \<le> x"
   and     sz: "n < LENGTH('a)"
   and     al: "is_aligned x n"
   shows   "alignUp a n \<le> x"
 proof (cases "is_aligned a n")
   case True
   then show ?thesis using sz le by (simp add: alignUp_idem)
 next
   case False
 
   then have anz: "a mod 2 ^ n \<noteq> 0"
     by (rule not_aligned_mod_nz)
 
   from al obtain k where xk: "x = 2 ^ n * of_nat k" and kv: "k < 2 ^ (LENGTH('a) - n)"
     by (auto elim!: is_alignedE)
 
   then have kn: "unat (of_nat k :: 'a word) * unat ((2::'a word) ^ n) < 2 ^ LENGTH('a)"
     using sz
     apply (subst unat_of_nat_eq)
      apply (erule order_less_le_trans)
      apply simp
     apply (subst mult.commute)
     apply simp
     apply (rule nat_less_power_trans)
      apply simp
     apply simp
     done
 
   have au: "alignUp a n = (a div 2 ^ n + 1) * 2 ^ n"
     by (rule alignUp_not_aligned_eq) fact+
   also have "\<dots> \<le> of_nat k * 2 ^ n"
   proof (rule word_mult_le_mono1 [OF inc_le _ kn])
     show "a div 2 ^ n < of_nat k" using kv xk le sz anz
       by (simp add: alignUp_div_helper)
 
     show "(0:: 'a word) < 2 ^ n" using sz by (simp add: p2_gt_0 sz)
   qed
 
   finally show ?thesis using xk by (simp add: field_simps)
 qed
 
 lemma alignUp_is_aligned_nz:
   fixes a :: "'a :: len word"
   assumes al: "is_aligned x n"
   and     sz: "n < LENGTH('a)"
   and     ax: "a \<le> x"
   and     az: "a \<noteq> 0"
   shows   "alignUp (a::'a :: len word) n \<noteq> 0"
 proof (cases "is_aligned a n")
   case True
   then have "alignUp a n = a" using sz by (simp add: alignUp_idem)
   then show ?thesis using az by simp
 next
   case False
   then have anz: "a mod 2 ^ n \<noteq> 0"
     by (rule not_aligned_mod_nz)
 
   {
     assume asm: "alignUp a n = 0"
 
     have lt0: "unat a div 2 ^ n < 2 ^ (LENGTH('a) - n)" using sz
       by (metis shiftr_div_2n' word_shiftr_lt)
 
     have leq: "2 ^ n * (unat a div 2 ^ n + 1) \<le> 2 ^ LENGTH('a)" using sz
       by (metis One_nat_def Suc_leI add.right_neutral add_Suc_right lt0 nat_le_power_trans
                 order_less_imp_le)
 
     from al obtain k where  kv: "k < 2 ^ (LENGTH('a) - n)" and xk: "x = 2 ^ n * of_nat k"
       by (auto elim!: is_alignedE)
 
     then have "a div 2 ^ n < of_nat k" using ax sz anz
       by (rule alignUp_div_helper)
 
     then have r: "unat a div 2 ^ n < k" using sz
       by (metis unat_div unat_less_helper unat_power_lower)
 
     have "alignUp a n = (a div 2 ^ n + 1) * 2 ^ n"
       by (rule alignUp_not_aligned_eq) fact+
 
     then have "\<dots> = 0" using asm by simp
     then have "2 ^ LENGTH('a) dvd 2 ^ n * (unat a div 2 ^ n + 1)"
       using sz by (simp add: unat_arith_simps ac_simps)
                   (simp add: unat_word_ariths mod_simps mod_eq_0_iff_dvd)
     with leq have "2 ^ n * (unat a div 2 ^ n + 1) = 2 ^ LENGTH('a)"
       by (force elim!: le_SucE)
     then have "unat a div 2 ^ n = 2 ^ LENGTH('a) div 2 ^ n - 1"
       by (metis (no_types, hide_lams) Groups.add_ac(2) add.right_neutral
                 add_diff_cancel_left' div_le_dividend div_mult_self4 gr_implies_not0
                 le_neq_implies_less power_eq_0_iff zero_neq_numeral)
     then have "unat a div 2 ^ n = 2 ^ (LENGTH('a) - n) - 1"
       using sz by (simp add: power_sub)
     then have "2 ^ (LENGTH('a) - n) - 1 < k" using r
       by simp
     then have False using kv by simp
   } then show ?thesis by clarsimp
 qed
 
 lemma alignUp_ar_helper:
   fixes a :: "'a :: len word"
   assumes al: "is_aligned x n"
   and     sz: "n < LENGTH('a)"
   and    sub: "{x..x + 2 ^ n - 1} \<subseteq> {a..b}"
   and    anz: "a \<noteq> 0"
   shows "a \<le> alignUp a n \<and> alignUp a n + 2 ^ n - 1 \<le> b"
 proof
   from al have xl: "x \<le> x + 2 ^ n - 1" by (simp add: is_aligned_no_overflow)
 
   from xl sub have ax: "a \<le> x"
     by (clarsimp elim!: range_subset_lower [where x = x])
 
   show "a \<le> alignUp a n"
   proof (rule alignUp_ge)
     show "alignUp a n \<noteq> 0" using al sz ax anz
       by (rule alignUp_is_aligned_nz)
   qed fact+
 
   show "alignUp a n + 2 ^ n - 1 \<le> b"
   proof (rule order_trans)
     from xl show tp: "x + 2 ^ n - 1 \<le> b" using sub
       by (clarsimp elim!: range_subset_upper [where x = x])
 
     from ax have "alignUp a n \<le> x"
       by (rule alignUp_le_greater_al) fact+
     then have "alignUp a n + (2 ^ n - 1) \<le> x + (2 ^ n - 1)"
       using xl al is_aligned_no_overflow' olen_add_eqv word_plus_mcs_3 by blast
     then show "alignUp a n + 2 ^ n - 1 \<le> x + 2 ^ n - 1"
       by (simp add: field_simps)
   qed
 qed
 
 lemma alignUp_def2:
   "alignUp a sz = a + 2 ^ sz - 1 && ~~ (mask sz)"
   unfolding alignUp_def[unfolded complement_def]
   by (simp add:mask_eq_decr_exp[symmetric,unfolded shiftl_t2n,simplified])
 
 lemma mask_out_first_mask_some:
   "\<lbrakk> x && ~~ (mask n) = y; n \<le> m \<rbrakk> \<Longrightarrow> x && ~~ (mask m) = y && ~~ (mask m)"
   by word_eqI_solve
 
 lemma gap_between_aligned:
   "\<lbrakk>a < (b :: 'a ::len word); is_aligned a n; is_aligned b n; n < LENGTH('a) \<rbrakk>
   \<Longrightarrow> a + (2^n - 1) < b"
   by (simp add: aligned_add_offset_less)
 
 lemma mask_out_add_aligned:
   assumes al: "is_aligned p n"
   shows "p + (q && ~~ (mask n)) = (p + q) && ~~ (mask n)"
   using mask_add_aligned [OF al]
   by (simp add: mask_out_sub_mask)
 
 lemma alignUp_def3:
   "alignUp a sz = 2^ sz + (a - 1 && ~~ (mask sz))"
   by (simp add: alignUp_def2 is_aligned_triv field_simps mask_out_add_aligned)
 
 lemma  alignUp_plus:
   "is_aligned w us \<Longrightarrow> alignUp (w + a) us  = w + alignUp a us"
   by (clarsimp simp: alignUp_def2 mask_out_add_aligned field_simps)
 
 lemma mask_lower_twice:
   "n \<le> m \<Longrightarrow> (x && ~~ (mask n)) && ~~ (mask m) = x && ~~ (mask m)"
   by word_eqI_solve
 
 lemma mask_lower_twice2:
   "(a && ~~ (mask n)) && ~~ (mask m) = a && ~~ (mask (max n m))"
   by word_eqI_solve
 
 lemma ucast_and_neg_mask:
   "ucast (x && ~~ (mask n)) = ucast x && ~~ (mask n)"
   by word_eqI_solve
 
 lemma ucast_and_mask:
   "ucast (x && mask n) = ucast x && mask n"
   by word_eqI_solve
 
 lemma ucast_mask_drop:
   "LENGTH('a :: len) \<le> n \<Longrightarrow> (ucast (x && mask n) :: 'a word) = ucast x"
   by word_eqI
 
 lemma alignUp_distance:
   "alignUp (q :: 'a :: len word) sz - q \<le> mask sz"
   by (metis (no_types) add.commute add_diff_cancel_left alignUp_def2 diff_add_cancel
                        mask_2pm1 subtract_mask(2) word_and_le1 word_sub_le_iff)
 
 lemma is_aligned_diff_neg_mask:
   "is_aligned p sz \<Longrightarrow> (p - q && ~~ (mask sz)) = (p - ((alignUp q sz) && ~~ (mask sz)))"
   apply (clarsimp simp only:word_and_le2 diff_conv_add_uminus)
   apply (subst mask_out_add_aligned[symmetric]; simp)
   apply (rule sum_to_zero)
   apply (subst add.commute)
   by (simp add: alignUp_distance and_mask_0_iff_le_mask is_aligned_neg_mask_eq mask_out_add_aligned)
 
 lemma map_bits_rev_to_bl:
   "map ((!!) x) [0..<size x] = rev (to_bl x)"
   by (auto simp: list_eq_iff_nth_eq test_bit_bl word_size)
 
 (* negating a mask which has been shifted to the very left *)
 lemma NOT_mask_shifted_lenword:
   "~~ (mask len << (LENGTH('a) - len) ::'a::len word) = mask (LENGTH('a) - len)"
   by (rule bit_word_eqI)
     (auto simp add: shiftl_word_eq word_size bit_not_iff bit_push_bit_iff bit_mask_iff)
 
 (* Comparisons between different word sizes. *)
 
 lemma eq_ucast_ucast_eq:
   "LENGTH('b) \<le> LENGTH('a) \<Longrightarrow> x = ucast y \<Longrightarrow> ucast x = y"
   for x :: "'a::len word" and y :: "'b::len word"
   by (simp add: is_down ucast_ucast_a)
 
 lemma le_ucast_ucast_le:
   "x \<le> ucast y \<Longrightarrow> ucast x \<le> y"
   for x :: "'a::len word" and y :: "'b::len word"
   by (smt le_unat_uoi linorder_not_less order_less_imp_le ucast_nat_def unat_arith_simps(1))
 
 lemma less_ucast_ucast_less:
   "LENGTH('b) \<le> LENGTH('a) \<Longrightarrow> x < ucast y \<Longrightarrow> ucast x < y"
   for x :: "'a::len word" and y :: "'b::len word"
   by (metis ucast_nat_def unat_mono unat_ucast_up_simp word_of_nat_less)
 
 lemma ucast_le_ucast:
   "LENGTH('a) \<le> LENGTH('b) \<Longrightarrow> (ucast x \<le> (ucast y::'b::len word)) = (x \<le> y)"
   for x :: "'a::len word"
   by (simp add: unat_arith_simps(1) unat_ucast_up_simp)
 
 lemmas ucast_up_mono_le = ucast_le_ucast[THEN iffD2]
 
 lemma ucast_le_ucast_eq:
   fixes x y :: "'a::len word"
   assumes x: "x < 2 ^ n"
   assumes y: "y < 2 ^ n"
   assumes n: "n = LENGTH('b::len)"
   shows "(UCAST('a \<rightarrow> 'b) x \<le> UCAST('a \<rightarrow> 'b) y) = (x \<le> y)"
   apply (rule iffI)
    apply (cases "LENGTH('b) < LENGTH('a)")
     apply (subst less_mask_eq[OF x, symmetric])
     apply (subst less_mask_eq[OF y, symmetric])
     apply (unfold n)
     apply (subst ucast_ucast_mask[symmetric])+
     apply (simp add: ucast_le_ucast)+
   apply (erule ucast_mono_le[OF _ y[unfolded n]])
   done
 
 lemma word_le_not_less:
   "((b::'a::len word) \<le> a) = (\<not>(a < b))"
   by fastforce
 
 lemma ucast_or_distrib:
   fixes x :: "'a::len word"
   fixes y :: "'a::len word"
   shows "(ucast (x || y) :: ('b::len) word) = ucast x || ucast y"
   by transfer simp
 
 lemma shiftr_less:
   "(w::'a::len word) < k \<Longrightarrow> w >> n < k"
   by (metis div_le_dividend le_less_trans shiftr_div_2n' unat_arith_simps(2))
 
 lemma word_and_notzeroD:
   "w && w' \<noteq> 0 \<Longrightarrow> w \<noteq> 0 \<and> w' \<noteq> 0"
   by auto
 
 lemma word_clz_max:
   "word_clz w \<le> size (w::'a::len word)"
   unfolding word_clz_def
   by (metis length_takeWhile_le word_size_bl)
 
 lemma word_clz_nonzero_max:
   fixes w :: "'a::len word"
   assumes nz: "w \<noteq> 0"
   shows "word_clz w < size (w::'a::len word)"
 proof -
   {
     assume a: "word_clz w = size (w::'a::len word)"
     hence "length (takeWhile Not (to_bl w)) = length (to_bl w)"
       by (simp add: word_clz_def word_size)
     hence allj: "\<forall>j\<in>set(to_bl w). \<not> j"
       by (metis a length_takeWhile_less less_irrefl_nat word_clz_def)
     hence "to_bl w = replicate (length (to_bl w)) False"
       by (fastforce intro!: list_of_false)
     hence "w = 0"
       by (metis to_bl_0 word_bl.Rep_eqD word_bl_Rep')
     with nz have False by simp
   }
   thus ?thesis using word_clz_max
     by (fastforce intro: le_neq_trans)
 qed
 
 lemma unat_add_lem':
   "(unat x + unat y < 2 ^ LENGTH('a)) \<Longrightarrow>
     (unat (x + y :: 'a :: len word) = unat x + unat y)"
   by (subst unat_add_lem[symmetric], assumption)
 
 lemma from_bool_eq_if':
   "((if P then 1 else 0) = from_bool Q) = (P = Q)"
   by (simp add: case_bool_If from_bool_def split: if_split)
 
 lemma word_exists_nth:
   "(w::'a::len word) \<noteq> 0 \<Longrightarrow> \<exists>i. w !! i"
   using word_log2_nth_same by blast
 
 lemma shiftr_le_0:
   "unat (w::'a::len word) < 2 ^ n \<Longrightarrow> w >> n = (0::'a::len word)"
   by (rule word_unat.Rep_eqD) (simp add: shiftr_div_2n')
 
 lemma of_nat_shiftl:
   "(of_nat x << n) = (of_nat (x * 2 ^ n) :: ('a::len) word)"
 proof -
   have "(of_nat x::'a word) << n = of_nat (2 ^ n) * of_nat x"
     using shiftl_t2n by (metis word_unat_power)
   thus ?thesis by simp
 qed
 
 lemma shiftl_1_not_0:
   "n < LENGTH('a) \<Longrightarrow> (1::'a::len word) << n \<noteq> 0"
   by (simp add: shiftl_t2n)
 
 lemma max_word_not_0 [simp]:
   "- 1 \<noteq> (0 :: 'a::len word)"
   by simp
 
 lemma ucast_zero_is_aligned:
   "UCAST('a::len \<rightarrow> 'b::len) w = 0 \<Longrightarrow> n \<le> LENGTH('b) \<Longrightarrow> is_aligned w n"
   by (clarsimp simp: is_aligned_mask word_eq_iff word_size nth_ucast)
 
 lemma unat_ucast_eq_unat_and_mask:
   "unat (UCAST('b::len \<rightarrow> 'a::len) w) = unat (w && mask LENGTH('a))"
   proof -
     have "unat (UCAST('b \<rightarrow> 'a) w) = unat (UCAST('a \<rightarrow> 'b) (UCAST('b \<rightarrow> 'a) w))"
       by (cases "LENGTH('a) < LENGTH('b)"; simp add: is_down ucast_ucast_a unat_ucast_up_simp)
     thus ?thesis using ucast_ucast_mask by simp
   qed
 
 lemma unat_max_word_pos[simp]: "0 < unat (- 1 :: 'a::len word)"
   using unat_gt_0 [of \<open>- 1 :: 'a::len word\<close>] by simp
 
 
 (* Miscellaneous conditional injectivity rules. *)
 
 lemma mult_pow2_inj:
   assumes ws: "m + n \<le> LENGTH('a)"
   assumes le: "x \<le> mask m" "y \<le> mask m"
   assumes eq: "x * 2^n = y * (2^n::'a::len word)"
   shows "x = y"
 proof (cases n)
   case 0 thus ?thesis using eq by simp
 next
   case (Suc n')
   have m_lt: "m < LENGTH('a)" using Suc ws by simp
   have xylt: "x < 2^m" "y < 2^m" using le m_lt unfolding mask_2pm1 by auto
   have lenm: "n \<le> LENGTH('a) - m" using ws by simp
   show ?thesis
     using eq xylt
     apply (fold shiftl_t2n[where n=n, simplified mult.commute])
     apply (simp only: word_bl.Rep_inject[symmetric] bl_shiftl)
     apply (erule ssubst[OF less_is_drop_replicate])+
     apply (clarsimp elim!: drop_eq_mono[OF lenm])
     done
 qed
 
 lemma word_of_nat_inj:
   assumes bounded: "x < 2 ^ LENGTH('a)" "y < 2 ^ LENGTH('a)"
   assumes of_nats: "of_nat x = (of_nat y :: 'a::len word)"
   shows "x = y"
   by (rule contrapos_pp[OF of_nats]; cases "x < y"; cases "y < x")
      (auto dest: bounded[THEN of_nat_mono_maybe])
 
 (* Sign extension from bit n. *)
 
 lemma sign_extend_bitwise_if:
   "i < size w \<Longrightarrow> sign_extend e w !! i \<longleftrightarrow> (if i < e then w !! i else w !! e)"
   by (simp add: sign_extend_def neg_mask_test_bit word_size)
 
 lemma sign_extend_bitwise_disj:
   "i < size w \<Longrightarrow> sign_extend e w !! i \<longleftrightarrow> i \<le> e \<and> w !! i \<or> e \<le> i \<and> w !! e"
   by (auto simp: sign_extend_bitwise_if)
 
 lemma sign_extend_bitwise_cases:
   "i < size w \<Longrightarrow> sign_extend e w !! i \<longleftrightarrow> (i \<le> e \<longrightarrow> w !! i) \<and> (e \<le> i \<longrightarrow> w !! e)"
   by (auto simp: sign_extend_bitwise_if)
 
 lemmas sign_extend_bitwise_if'[word_eqI_simps] = sign_extend_bitwise_if[simplified word_size]
 lemmas sign_extend_bitwise_disj' = sign_extend_bitwise_disj[simplified word_size]
 lemmas sign_extend_bitwise_cases' = sign_extend_bitwise_cases[simplified word_size]
 
 (* Often, it is easier to reason about an operation which does not overwrite
    the bit which determines which mask operation to apply. *)
 lemma sign_extend_def':
   "sign_extend n w = (if w !! n then w || ~~ (mask (Suc n)) else w && mask (Suc n))"
   by word_eqI (auto dest: less_antisym)
 
 lemma sign_extended_sign_extend:
   "sign_extended n (sign_extend n w)"
   by (clarsimp simp: sign_extended_def word_size sign_extend_bitwise_if')
 
 lemma sign_extended_iff_sign_extend:
   "sign_extended n w \<longleftrightarrow> sign_extend n w = w"
   apply (rule iffI)
    apply (word_eqI, rename_tac i)
    apply (case_tac "n < i"; simp add: sign_extended_def word_size)
   apply (erule subst, rule sign_extended_sign_extend)
   done
 
 lemma sign_extended_weaken:
   "sign_extended n w \<Longrightarrow> n \<le> m \<Longrightarrow> sign_extended m w"
   unfolding sign_extended_def by (cases "n < m") auto
 
 lemma sign_extend_sign_extend_eq:
   "sign_extend m (sign_extend n w) = sign_extend (min m n) w"
   by word_eqI
 
 lemma sign_extended_high_bits:
   "\<lbrakk> sign_extended e p; j < size p; e \<le> i; i < j \<rbrakk> \<Longrightarrow> p !! i = p !! j"
   by (drule (1) sign_extended_weaken; simp add: sign_extended_def)
 
 lemma sign_extend_eq:
   "w && mask (Suc n) = v && mask (Suc n) \<Longrightarrow> sign_extend n w = sign_extend n v"
   by word_eqI_solve
 
 lemma sign_extended_add:
   assumes p: "is_aligned p n"
   assumes f: "f < 2 ^ n"
   assumes e: "n \<le> e"
   assumes "sign_extended e p"
   shows "sign_extended e (p + f)"
 proof (cases "e < size p")
   case True
   note and_or = is_aligned_add_or[OF p f]
   have "\<not> f !! e"
     using True e less_2p_is_upper_bits_unset[THEN iffD1, OF f]
     by (fastforce simp: word_size)
   hence i: "(p + f) !! e = p !! e"
     by (simp add: and_or)
   have fm: "f && mask e = f"
     by (fastforce intro: subst[where P="\<lambda>f. f && mask e = f", OF less_mask_eq[OF f]]
                   simp: mask_twice e)
   show ?thesis
     using assms
      apply (simp add: sign_extended_iff_sign_extend sign_extend_def i)
      apply (simp add: and_or word_bw_comms[of p f])
      apply (clarsimp simp: word_ao_dist fm word_bw_assocs split: if_splits)
     done
 next
   case False thus ?thesis
     by (simp add: sign_extended_def word_size)
 qed
 
 lemma sign_extended_neq_mask:
   "\<lbrakk>sign_extended n ptr; m \<le> n\<rbrakk> \<Longrightarrow> sign_extended n (ptr && ~~ (mask m))"
   by (fastforce simp: sign_extended_def word_size neg_mask_test_bit)
 
 (* Uints *)
 
 lemma uints_mono_iff: "uints l \<subseteq> uints m \<longleftrightarrow> l \<le> m"
   using power_increasing_iff[of "2::int" l m]
   apply (auto simp: uints_num subset_iff simp del: power_increasing_iff)
   by (meson less_irrefl not_less zle2p)
 
 lemmas uints_monoI = uints_mono_iff[THEN iffD2]
 
 lemma Bit_in_uints_Suc: "of_bool c + 2 * w \<in> uints (Suc m)" if "w \<in> uints m"
   using that
   by (auto simp: uints_num)
 
 lemma Bit_in_uintsI: "of_bool c + 2 * w \<in> uints m" if "w \<in> uints (m - 1)" "m > 0"
   using Bit_in_uints_Suc[OF that(1)] that(2)
   by auto
 
 lemma bin_cat_in_uintsI:
   \<open>bin_cat a n b \<in> uints m\<close> if \<open>a \<in> uints l\<close> \<open>m \<ge> l + n\<close>
 proof -
   from \<open>m \<ge> l + n\<close> obtain q where \<open>m = l + n + q\<close>
     using le_Suc_ex by blast
   then have \<open>(2::int) ^ m = 2 ^ n * 2 ^ (l + q)\<close>
     by (simp add: ac_simps power_add)
   moreover have \<open>a mod 2 ^ (l + q) = a\<close>
     using \<open>a \<in> uints l\<close>
     by (auto simp add: uints_def take_bit_eq_mod power_add Divides.mod_mult2_eq)
   ultimately have \<open>concat_bit n b a = take_bit m (concat_bit n b a)\<close>
     by (simp add: concat_bit_eq take_bit_eq_mod push_bit_eq_mult Divides.mod_mult2_eq)
   then show ?thesis
     by (simp add: uints_def)
 qed
 
 lemma bin_cat_cong: "bin_cat a n b = bin_cat c m d"
   if "n = m" "a = c" "bintrunc m b = bintrunc m d"
   using that(3) unfolding that(1,2) by (simp add: bin_cat_eq_push_bit_add_take_bit)
 
 lemma bin_cat_eqD1: "bin_cat a n b = bin_cat c n d \<Longrightarrow> a = c"
   by (metis drop_bit_bin_cat_eq)
 
 lemma bin_cat_eqD2: "bin_cat a n b = bin_cat c n d \<Longrightarrow> bintrunc n b = bintrunc n d"
   by (metis take_bit_bin_cat_eq)
   
 lemma bin_cat_inj: "(bin_cat a n b) = bin_cat c n d \<longleftrightarrow> a = c \<and> bintrunc n b = bintrunc n d"
   by (auto intro: bin_cat_cong bin_cat_eqD1 bin_cat_eqD2)
 
 lemma word_of_int_bin_cat_eq_iff:
   "(word_of_int (bin_cat (uint a) LENGTH('b) (uint b))::'c::len word) =
   word_of_int (bin_cat (uint c) LENGTH('b) (uint d)) \<longleftrightarrow> b = d \<and> a = c"
   if "LENGTH('a) + LENGTH('b) \<le> LENGTH('c)"
   for a::"'a::len word" and b::"'b::len word"
   by (subst word_uint.Abs_inject)
      (auto simp: bin_cat_inj intro!: that bin_cat_in_uintsI)
 
 lemma word_cat_inj: "(word_cat a b::'c::len word) = word_cat c d \<longleftrightarrow> a = c \<and> b = d"
   if "LENGTH('a) + LENGTH('b) \<le> LENGTH('c)"
   for a::"'a::len word" and b::"'b::len word"
   using word_of_int_bin_cat_eq_iff [OF that, of b a d c]
   by transfer auto
 
 lemma p2_eq_1: "2 ^ n = (1::'a::len word) \<longleftrightarrow> n = 0"
 proof -
   have "2 ^ n = (1::'a word) \<Longrightarrow> n = 0"
     by (metis One_nat_def not_less one_less_numeral_iff p2_eq_0 p2_gt_0 power_0 power_0
         power_inject_exp semiring_norm(76) unat_power_lower zero_neq_one)
   then show ?thesis by auto
 qed
 
 (* usually: x,y = (len_of TYPE ('a)) *)
 lemma bitmagic_zeroLast_leq_or1Last:
   "(a::('a::len) word) AND (mask len << x - len) \<le> a OR mask (y - len)"
   by (meson le_word_or2 order_trans word_and_le2)
 
 
 lemma zero_base_lsb_imp_set_eq_as_bit_operation:
   fixes base ::"'a::len word"
   assumes valid_prefix: "mask (LENGTH('a) - len) AND base = 0"
   shows "(base = NOT (mask (LENGTH('a) - len)) AND a) \<longleftrightarrow>
          (a \<in> {base .. base OR mask (LENGTH('a) - len)})"
 proof
   have helper3: "x OR y = x OR y AND NOT x" for x y ::"'a::len word" by (simp add: word_oa_dist2)
   from assms show "base = NOT (mask (LENGTH('a) - len)) AND a \<Longrightarrow>
                     a \<in> {base..base OR mask (LENGTH('a) - len)}"
     apply(simp add: word_and_le1)
     apply(metis helper3 le_word_or2 word_bw_comms(1) word_bw_comms(2))
   done
 next
   assume "a \<in> {base..base OR mask (LENGTH('a) - len)}"
   hence a: "base \<le> a \<and> a \<le> base OR mask (LENGTH('a) - len)" by simp
   show "base = NOT (mask (LENGTH('a) - len)) AND a"
   proof -
     have f2: "\<forall>x\<^sub>0. base AND NOT (mask x\<^sub>0) \<le> a AND NOT (mask x\<^sub>0)"
       using a neg_mask_mono_le by blast
     have f3: "\<forall>x\<^sub>0. a AND NOT (mask x\<^sub>0) \<le> (base OR mask (LENGTH('a) - len)) AND NOT (mask x\<^sub>0)"
       using a neg_mask_mono_le by blast
     have f4: "base = base AND NOT (mask (LENGTH('a) - len))"
       using valid_prefix by (metis mask_eq_0_eq_x word_bw_comms(1))
     hence f5: "\<forall>x\<^sub>6. (base OR x\<^sub>6) AND NOT (mask (LENGTH('a) - len)) =
                       base OR x\<^sub>6 AND NOT (mask (LENGTH('a) - len))"
       using word_ao_dist by (metis)
     have f6: "\<forall>x\<^sub>2 x\<^sub>3. a AND NOT (mask x\<^sub>2) \<le> x\<^sub>3 \<or>
                       \<not> (base OR mask (LENGTH('a) - len)) AND NOT (mask x\<^sub>2) \<le> x\<^sub>3"
       using f3 dual_order.trans by auto
     have "base = (base OR mask (LENGTH('a) - len)) AND NOT (mask (LENGTH('a) - len))"
       using f5 by auto
     hence "base = a AND NOT (mask (LENGTH('a) - len))"
       using f2 f4 f6 by (metis eq_iff)
     thus "base = NOT (mask (LENGTH('a) - len)) AND a"
       by (metis word_bw_comms(1))
   qed
 qed
 
 lemma unat_minus_one_word:
   "unat (-1 :: 'a :: len word) = 2 ^ LENGTH('a) - 1"
   by (subst minus_one_word)
      (subst unat_sub_if', clarsimp)
 
 lemma of_nat_eq_signed_scast:
   "(of_nat x = (y :: ('a::len) signed word))
    = (of_nat x = (scast y :: 'a word))"
   by (metis scast_of_nat scast_scast_id(2))
 
 lemma word_ctz_le:
   "word_ctz (w :: ('a::len word)) \<le> LENGTH('a)"
   apply (clarsimp simp: word_ctz_def)
   apply (rule nat_le_Suc_less_imp[where y="LENGTH('a) + 1" , simplified])
   apply (rule order_le_less_trans[OF List.length_takeWhile_le])
   apply simp
   done
 
 lemma word_ctz_less:
   "w \<noteq> 0 \<Longrightarrow> word_ctz (w :: ('a::len word)) < LENGTH('a)"
   apply (clarsimp simp: word_ctz_def eq_zero_set_bl)
   apply (rule order_less_le_trans[OF length_takeWhile_less])
    apply fastforce+
   done
 
 lemma word_ctz_not_minus_1:
   "1 < LENGTH('a) \<Longrightarrow> of_nat (word_ctz (w :: 'a :: len word)) \<noteq> (- 1 :: 'a::len word)"
   by (metis (mono_tags) One_nat_def add.right_neutral add_Suc_right le_diff_conv le_less_trans
                         n_less_equal_power_2 not_le suc_le_pow_2 unat_minus_one_word unat_of_nat_len
                         word_ctz_le)
 
 lemma word_aligned_add_no_wrap_bounded:
   "\<lbrakk> w + 2^n \<le> x; w + 2^n \<noteq> 0; is_aligned w n \<rbrakk> \<Longrightarrow> (w::'a::len word) < x"
   by (blast dest: is_aligned_no_overflow le_less_trans word_leq_le_minus_one)
 
 lemma mask_Suc:
   "mask (Suc n) = (2 :: 'a::len word) ^ n + mask n"
   by (simp add: mask_eq_decr_exp)
 
 lemma is_aligned_no_overflow_mask:
   "is_aligned x n \<Longrightarrow> x \<le> x + mask n"
   by (simp add: mask_eq_decr_exp) (erule is_aligned_no_overflow')
 
 lemma is_aligned_mask_offset_unat:
   fixes off :: "('a::len) word"
   and     x :: "'a word"
   assumes al: "is_aligned x sz"
   and   offv: "off \<le> mask sz"
   shows  "unat x + unat off < 2 ^ LENGTH('a)"
 proof cases
   assume szv: "sz < LENGTH('a)"
   from al obtain k where xv: "x = 2 ^ sz * (of_nat k)"
     and kl: "k < 2 ^ (LENGTH('a) - sz)"
     by (auto elim: is_alignedE)
 
   from offv szv have offv': "unat off < 2 ^ sz"
     by (simp add: mask_2pm1 unat_less_power)
 
   show ?thesis using szv
     using al is_aligned_no_wrap''' offv' by blast
 next
   assume "\<not> sz < LENGTH('a)"
   with al have "x = 0" by - word_eqI
   thus ?thesis by simp
 qed
 
 lemma of_bl_max:
   "(of_bl xs :: 'a::len word) \<le> mask (length xs)"
   apply (induct xs)
    apply simp
   apply (simp add: of_bl_Cons mask_Suc)
   apply (rule conjI; clarsimp)
    apply (erule word_plus_mono_right)
    apply (rule is_aligned_no_overflow_mask)
    apply (rule is_aligned_triv)
   apply (simp add: word_le_nat_alt)
   apply (subst unat_add_lem')
    apply (rule is_aligned_mask_offset_unat)
     apply (rule is_aligned_triv)
    apply (simp add: mask_eq_decr_exp)
   apply simp
   done
 
 lemma mask_over_length:
   "LENGTH('a) \<le> n \<Longrightarrow> mask n = (-1::'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 lemma is_aligned_over_length:
   "\<lbrakk> is_aligned p n; LENGTH('a) \<le> n \<rbrakk> \<Longrightarrow> (p::'a::len word) = 0"
   by (simp add: is_aligned_mask mask_over_length)
 
 lemma Suc_2p_unat_mask:
   "n < LENGTH('a) \<Longrightarrow> Suc (2 ^ n * k + unat (mask n :: 'a::len word)) = 2 ^ n * (k+1)"
   by (simp add: unat_mask)
 
 lemma is_aligned_add_step_le:
   "\<lbrakk> is_aligned (a::'a::len word) n; is_aligned b n; a < b; b \<le> a + mask n \<rbrakk> \<Longrightarrow> False"
   apply (simp flip: not_le)
   apply (erule notE)
   apply (cases "LENGTH('a) \<le> n")
    apply (drule (1) is_aligned_over_length)+
    apply (drule mask_over_length)
    apply clarsimp
   apply (clarsimp simp: word_le_nat_alt not_less)
   apply (subst (asm) unat_plus_simple[THEN iffD1], erule is_aligned_no_overflow_mask)
   apply (clarsimp simp: is_aligned_def dvd_def word_le_nat_alt)
   apply (drule le_imp_less_Suc)
   apply (simp add: Suc_2p_unat_mask)
   by (metis Groups.mult_ac(2) Suc_leI linorder_not_less mult_le_mono order_refl times_nat.simps(2))
 
 lemma power_2_mult_step_le:
   "\<lbrakk>n' \<le> n; 2 ^ n' * k' < 2 ^ n * k\<rbrakk> \<Longrightarrow> 2 ^ n' * (k' + 1) \<le> 2 ^ n * (k::nat)"
   apply (cases "n'=n", simp)
    apply (metis Suc_leI le_refl mult_Suc_right mult_le_mono semiring_normalization_rules(7))
   apply (drule (1) le_neq_trans)
   apply clarsimp
   apply (subgoal_tac "\<exists>m. n = n' + m")
    prefer 2
    apply (simp add: le_Suc_ex)
   apply (clarsimp simp: power_add)
   by (metis Suc_leI mult.assoc mult_Suc_right nat_mult_le_cancel_disj)
 
 lemma aligned_mask_step:
   "\<lbrakk> n' \<le> n; p' \<le> p + mask n; is_aligned p n; is_aligned p' n' \<rbrakk> \<Longrightarrow>
    (p'::'a::len word) + mask n' \<le> p + mask n"
   apply (cases "LENGTH('a) \<le> n")
    apply (frule (1) is_aligned_over_length)
    apply (drule mask_over_length)
    apply clarsimp
   apply (simp add: not_le)
   apply (simp add: word_le_nat_alt unat_plus_simple)
   apply (subst unat_plus_simple[THEN iffD1], erule is_aligned_no_overflow_mask)+
   apply (subst (asm) unat_plus_simple[THEN iffD1], erule is_aligned_no_overflow_mask)
   apply (clarsimp simp: is_aligned_def dvd_def)
   apply (rename_tac k k')
   apply (thin_tac "unat p = x" for p x)+
   apply (subst Suc_le_mono[symmetric])
   apply (simp only: Suc_2p_unat_mask)
   apply (drule le_imp_less_Suc, subst (asm) Suc_2p_unat_mask, assumption)
   apply (erule (1) power_2_mult_step_le)
   done
 
 lemma mask_mono:
   "sz' \<le> sz \<Longrightarrow> mask sz' \<le> (mask sz :: 'a::len word)"
   by (simp add: le_mask_iff shiftr_mask_le)
 
 lemma aligned_mask_disjoint:
   "\<lbrakk> is_aligned (a :: 'a :: len word) n; b \<le> mask n \<rbrakk> \<Longrightarrow> a && b = 0"
   by word_eqI_solve
 
 lemma word_and_or_mask_aligned:
   "\<lbrakk> is_aligned a n; b \<le> mask n \<rbrakk> \<Longrightarrow> a + b = a || b"
   by (simp add: aligned_mask_disjoint word_plus_and_or_coroll)
 
 lemma word_and_or_mask_aligned2:
   \<open>is_aligned b n \<Longrightarrow> a \<le> mask n \<Longrightarrow> a + b = a || b\<close>
   using word_and_or_mask_aligned [of b n a] by (simp add: ac_simps)
   
 lemma is_aligned_ucastI:
   "is_aligned w n \<Longrightarrow> is_aligned (ucast w) n"
   by (clarsimp simp: word_eqI_simps)
 
 lemma ucast_le_maskI:
   "a \<le> mask n \<Longrightarrow> UCAST('a::len \<rightarrow> 'b::len) a \<le> mask n"
   by (metis and_mask_eq_iff_le_mask ucast_and_mask)
 
 lemma ucast_add_mask_aligned:
   "\<lbrakk> a \<le> mask n; is_aligned b n \<rbrakk> \<Longrightarrow> UCAST ('a::len \<rightarrow> 'b::len) (a + b) = ucast a + ucast b"
   by (metis add.commute is_aligned_ucastI ucast_le_maskI ucast_or_distrib word_and_or_mask_aligned)
 
 lemma ucast_shiftl:
   "LENGTH('b) \<le> LENGTH ('a) \<Longrightarrow> UCAST ('a::len \<rightarrow> 'b::len) x << n = ucast (x << n)"
   by word_eqI_solve
 
 lemma ucast_leq_mask:
   "LENGTH('a) \<le> n \<Longrightarrow> ucast (x::'a::len word) \<le> mask n"
   by (clarsimp simp: le_mask_high_bits word_size nth_ucast)
 
 lemma shiftl_inj:
   "\<lbrakk> x << n = y << n; x \<le> mask (LENGTH('a)-n); y \<le> mask (LENGTH('a)-n) \<rbrakk> \<Longrightarrow>
    x = (y :: 'a :: len word)"
   apply word_eqI
   apply (rename_tac n')
   apply (case_tac "LENGTH('a) - n \<le> n'", simp)
   by (metis add.commute add.right_neutral diff_add_inverse le_diff_conv linorder_not_less zero_order(1))
 
 lemma distinct_word_add_ucast_shift_inj:
   "\<lbrakk> p + (UCAST('a::len \<rightarrow> 'b::len) off << n) = p' + (ucast off' << n);
      is_aligned p n'; is_aligned p' n'; n' = n + LENGTH('a); n' < LENGTH('b) \<rbrakk>
    \<Longrightarrow> p' = p \<and> off' = off"
   apply (simp add: word_and_or_mask_aligned le_mask_shiftl_le_mask[where n="LENGTH('a)"]
                    ucast_leq_mask)
   apply (simp add: is_aligned_nth)
   apply (rule conjI; word_eqI)
    apply (metis add.commute test_bit_conj_lt diff_add_inverse le_diff_conv nat_less_le)
   apply (rename_tac i)
   apply (erule_tac x="i+n" in allE)
   apply simp
   done
 
 lemma aligned_add_mask_lessD:
   "\<lbrakk> x + mask n < y; is_aligned x n \<rbrakk> \<Longrightarrow> x < y" for y::"'a::len word"
   by (metis is_aligned_no_overflow' mask_2pm1 order_le_less_trans)
 
 lemma aligned_add_mask_less_eq:
   "\<lbrakk> is_aligned x n; is_aligned y n;  n < LENGTH('a) \<rbrakk> \<Longrightarrow> (x + mask n < y) = (x < y)"
   for y::"'a::len word"
   using aligned_add_mask_lessD is_aligned_add_step_le word_le_not_less by blast
 
 lemma word_upto_Nil:
   "y < x \<Longrightarrow> [x .e. y ::'a::len word] = []"
   by (simp add: upto_enum_red not_le word_less_nat_alt)
 
 lemma word_enum_decomp_elem:
   assumes "[x .e. (y ::'a::len word)] = as @ a # bs"
   shows "x \<le> a \<and> a \<le> y"
 proof -
   have "set as \<subseteq> set [x .e. y] \<and> a \<in> set [x .e. y]"
     using assms by (auto dest: arg_cong[where f=set])
   then show ?thesis by auto
 qed
 
 lemma max_word_not_less[simp]:
    "\<not> max_word < x"
   by (simp add: not_less)
 
 lemma word_enum_prefix:
   "[x .e. (y ::'a::len word)] = as @ a # bs \<Longrightarrow> as = (if x < a then [x .e. a - 1] else [])"
   apply (induct as arbitrary: x; clarsimp)
    apply (case_tac "x < y")
     prefer 2
     apply (case_tac "x = y", simp)
     apply (simp add: not_less)
     apply (drule (1) dual_order.not_eq_order_implies_strict)
     apply (simp add: word_upto_Nil)
    apply (simp add: word_upto_Cons_eq)
   apply (case_tac "x < y")
    prefer 2
    apply (case_tac "x = y", simp)
    apply (simp add: not_less)
    apply (drule (1) dual_order.not_eq_order_implies_strict)
    apply (simp add: word_upto_Nil)
   apply (clarsimp simp: word_upto_Cons_eq)
   apply (frule word_enum_decomp_elem)
   apply clarsimp
   apply (rule conjI)
    prefer 2
    apply (subst word_Suc_le[symmetric]; clarsimp)
   apply (drule meta_spec)
   apply (drule (1) meta_mp)
   apply clarsimp
   apply (rule conjI; clarsimp)
   apply (subst (2) word_upto_Cons_eq)
    apply unat_arith
   apply simp
   done
 
 lemma word_enum_decomp_set:
   "[x .e. (y ::'a::len word)] = as @ a # bs \<Longrightarrow> a \<notin> set as"
   by (metis distinct_append distinct_enum_upto' not_distinct_conv_prefix)
 
 lemma word_enum_decomp:
   assumes "[x .e. (y ::'a::len word)] = as @ a # bs"
   shows "x \<le> a \<and> a \<le> y \<and> a \<notin> set as \<and> (\<forall>z \<in> set as. x \<le> z \<and> z \<le> y)"
 proof -
   from assms
   have "set as \<subseteq> set [x .e. y] \<and> a \<in> set [x .e. y]"
     by (auto dest: arg_cong[where f=set])
   with word_enum_decomp_set[OF assms]
   show ?thesis by auto
 qed
 
 lemma of_nat_unat_le_mask_ucast:
   "\<lbrakk>of_nat (unat t) = w; t \<le> mask LENGTH('a)\<rbrakk> \<Longrightarrow> t = UCAST('a::len \<rightarrow> 'b::len) w"
   by (clarsimp simp: ucast_nat_def ucast_ucast_mask simp flip: and_mask_eq_iff_le_mask)
 
 lemma fold_eq_0_to_bool:
   "(v = 0) = (\<not> to_bool v)"
   by (simp add: to_bool_def)
 
 lemma less_diff_gt0:
   "a < b \<Longrightarrow> (0 :: 'a :: len word) < b - a"
   by unat_arith
 
 lemma unat_plus_gt:
   "unat ((a :: 'a :: len word) + b) \<le> unat a + unat b"
   by (clarsimp simp: unat_plus_if_size)
 
 lemma const_less:
   "\<lbrakk> (a :: 'a :: len word) - 1 < b; a \<noteq> b \<rbrakk> \<Longrightarrow> a < b"
   by (metis less_1_simp word_le_less_eq)
 
 lemma add_mult_aligned_neg_mask:
   \<open>(x + y * m) && ~~(mask n) = (x && ~~(mask n)) + y * m\<close>
   if \<open>m && (2 ^ n - 1) = 0\<close>
   by (metis (no_types, hide_lams)
     add.assoc add.commute add.right_neutral add_uminus_conv_diff
    mask_eq_decr_exp mask_eqs(2) mask_eqs(6) mult.commute mult_zero_left
    subtract_mask(1) that)
 
 lemma unat_of_nat_minus_1:
   "\<lbrakk> n < 2 ^ LENGTH('a); n \<noteq> 0 \<rbrakk> \<Longrightarrow> unat ((of_nat n:: 'a :: len word) - 1) = n - 1"
   by (simp add: unat_eq_of_nat)
 
 lemma word_eq_zeroI:
   "a \<le> a - 1 \<Longrightarrow> a = 0" for a :: "'a :: len word"
   by (simp add: word_must_wrap)
 
 lemma word_add_format:
   "(-1 :: 'a :: len  word) + b + c = b + (c - 1)"
   by simp
 
 lemma upto_enum_word_nth:
   "\<lbrakk> i \<le> j; k \<le> unat (j - i) \<rbrakk> \<Longrightarrow> [i .e. j] ! k = i + of_nat k"
   apply (clarsimp simp: upto_enum_def nth_append)
   apply (clarsimp simp: word_le_nat_alt[symmetric])
   apply (rule conjI, clarsimp)
    apply (subst toEnum_of_nat, unat_arith)
    apply unat_arith
   apply (clarsimp simp: not_less unat_sub[symmetric])
   apply unat_arith
   done
 
 lemma upto_enum_step_nth:
   "\<lbrakk> a \<le> c; n \<le> unat ((c - a) div (b - a)) \<rbrakk>
    \<Longrightarrow> [a, b .e. c] ! n = a + of_nat n * (b - a)"
   by (clarsimp simp: upto_enum_step_def not_less[symmetric] upto_enum_word_nth)
 
 lemma upto_enum_inc_1_len:
   "a < - 1 \<Longrightarrow> [(0 :: 'a :: len word) .e. 1 + a] = [0 .e. a] @ [1 + a]"
   apply (simp add: upto_enum_word)
   apply (subgoal_tac "unat (1+a) = 1 + unat a")
    apply simp
   apply (subst unat_plus_simple[THEN iffD1])
    apply (metis add.commute no_plus_overflow_neg olen_add_eqv)
   apply unat_arith
   done
 
 lemma neg_mask_add:
   "y && mask n = 0 \<Longrightarrow> x + y && ~~(mask n) = (x && ~~(mask n)) + y"
   by (clarsimp simp: mask_out_sub_mask mask_eqs(7)[symmetric] mask_twice)
 
 lemma shiftr_shiftl_shiftr[simp]:
   "(x :: 'a :: len word)  >> a << a >> a = x >> a"
   by word_eqI_solve
 
 lemma add_right_shift:
   "\<lbrakk> x && mask n = 0; y && mask n = 0; x \<le> x + y \<rbrakk>
    \<Longrightarrow> (x + y :: ('a :: len) word) >> n = (x >> n) + (y >> n)"
   apply (simp add: no_olen_add_nat is_aligned_mask[symmetric])
   apply (simp add: unat_arith_simps shiftr_div_2n' split del: if_split)
   apply (subst if_P)
    apply (erule order_le_less_trans[rotated])
    apply (simp add: add_mono)
   apply (simp add: shiftr_div_2n' is_aligned_def)
   done
 
 lemma sub_right_shift:
   "\<lbrakk> x && mask n = 0; y && mask n = 0; y \<le> x \<rbrakk>
    \<Longrightarrow> (x - y) >> n = (x >> n :: 'a :: len word) - (y >> n)"
   using add_right_shift[where x="x - y" and y=y and n=n]
   by (simp add: aligned_sub_aligned is_aligned_mask[symmetric] word_sub_le)
 
 lemma and_and_mask_simple:
   "y && mask n = mask n \<Longrightarrow> (x && y) && mask n = x && mask n"
   by (simp add: ac_simps)
 
 lemma and_and_mask_simple_not:
   "y && mask n = 0 \<Longrightarrow> (x && y) && mask n = 0"
   by (simp add: ac_simps)
 
 lemma word_and_le':
   "b \<le> c \<Longrightarrow> (a :: 'a :: len word) && b \<le> c"
   by (metis word_and_le1 order_trans)
 
 lemma word_and_less':
   "b < c \<Longrightarrow> (a :: 'a :: len word) && b < c"
   by (metis word_and_le1 xtr7)
 
 lemma shiftr_w2p:
   "x < LENGTH('a) \<Longrightarrow> 2 ^ x = (2 ^ (LENGTH('a) - 1) >> (LENGTH('a) - 1 - x) :: 'a :: len word)"
   by word_eqI_solve
 
 lemma t2p_shiftr:
   "\<lbrakk> b \<le> a; a < LENGTH('a) \<rbrakk> \<Longrightarrow> (2 :: 'a :: len word) ^ a >> b = 2 ^ (a - b)"
   by word_eqI_solve
 
 lemma scast_1[simp]:
   "scast (1 :: 'a :: len signed word) = (1 :: 'a word)"
   by simp
 
 lemma ucast_ucast_mask_eq:
   "\<lbrakk> UCAST('a::len \<rightarrow> 'b::len) x = y; x && mask LENGTH('b) = x \<rbrakk> \<Longrightarrow> x = ucast y"
   by word_eqI_solve
 
 lemma ucast_up_eq:
   "\<lbrakk> ucast x = (ucast y::'b::len word); LENGTH('a) \<le> LENGTH ('b) \<rbrakk>
    \<Longrightarrow> ucast x = (ucast y::'a::len word)"
   by word_eqI_solve
 
 lemma ucast_up_neq:
   "\<lbrakk> ucast x \<noteq> (ucast y::'b::len word); LENGTH('b) \<le> LENGTH ('a) \<rbrakk>
    \<Longrightarrow> ucast x \<noteq> (ucast y::'a::len word)"
   by (fastforce dest: ucast_up_eq)
 
 lemma mask_AND_less_0:
   "\<lbrakk> x && mask n = 0; m \<le> n \<rbrakk> \<Longrightarrow> x && mask m = 0"
   by (metis mask_twice2 word_and_notzeroD)
 
 lemma mask_len_id [simp]:
   "(x :: 'a :: len word) && mask LENGTH('a) = x"
   using uint_lt2p [of x] by (simp add: mask_eq_iff)
 
 lemma scast_ucast_down_same:
   "LENGTH('b) \<le> LENGTH('a) \<Longrightarrow> SCAST('a \<rightarrow> 'b) = UCAST('a::len \<rightarrow> 'b::len)"
   by (simp add: down_cast_same is_down)
 
 lemma word_aligned_0_sum:
   "\<lbrakk> a + b = 0; is_aligned (a :: 'a :: len word) n; b \<le> mask n; n < LENGTH('a) \<rbrakk>
    \<Longrightarrow> a = 0 \<and> b = 0"
   by (simp add: word_plus_and_or_coroll aligned_mask_disjoint word_or_zero)
 
 lemma mask_eq1_nochoice:
   "\<lbrakk> LENGTH('a) > 1; (x :: 'a :: len word) && 1 = x \<rbrakk> \<Longrightarrow> x = 0 \<or> x = 1"
   by (metis word_and_1)
 
 lemma pow_mono_leq_imp_lt:
   "x \<le> y \<Longrightarrow> x < 2 ^ y"
   by (simp add: le_less_trans)
 
 lemma unat_of_nat_ctz_mw:
   "unat (of_nat (word_ctz (w :: 'a :: len word)) :: 'a :: len word) = word_ctz w"
   using word_ctz_le[where w=w, simplified] unat_of_nat_eq[where x="word_ctz w" and 'a="'a"]
         pow_mono_leq_imp_lt
   by simp
 
 lemma unat_of_nat_ctz_smw:
   "unat (of_nat (word_ctz (w :: 'a :: len word)) :: 'a :: len sword) = word_ctz w"
   using word_ctz_le[where w=w, simplified] unat_of_nat_eq[where x="word_ctz w" and 'a="'a"]
         pow_mono_leq_imp_lt
   by (metis le_unat_uoi le_unat_uoi linorder_neqE_nat nat_less_le scast_of_nat
             word_unat.Rep_inverse)
 
 lemma shiftr_and_eq_shiftl:
   "(w >> n) && x = y \<Longrightarrow> w && (x << n) = (y << n)" for y :: "'a:: len word"
   by (metis (no_types, lifting) and_not_mask bit.conj_ac(1) bit.conj_ac(2) mask_eq_0_eq_x shiftl_mask_is_0 shiftl_over_and_dist)
 
 lemma neg_mask_combine:
   "~~(mask a) && ~~(mask b) = ~~(mask (max a b))"
   by (auto simp: word_ops_nth_size word_size intro!: word_eqI)
 
 lemma neg_mask_twice:
   "x && ~~(mask n) && ~~(mask m) = x && ~~(mask (max n m))"
   by (metis neg_mask_combine)
 
 lemma multiple_mask_trivia:
   "n \<ge> m \<Longrightarrow> (x && ~~(mask n)) + (x && mask n && ~~(mask m)) = x && ~~(mask m)"
   apply (rule trans[rotated], rule_tac w="mask n" in word_plus_and_or_coroll2)
   apply (simp add: word_bw_assocs word_bw_comms word_bw_lcs neg_mask_twice
                    max_absorb2)
   done
 
 lemma add_mask_lower_bits':
   "\<lbrakk> len = LENGTH('a); is_aligned (x :: 'a :: len word) n;
      \<forall>n' \<ge> n. n' < len \<longrightarrow> \<not> p !! n' \<rbrakk>
    \<Longrightarrow> x + p && ~~(mask n) = x"
   using add_mask_lower_bits by auto
 
 lemma neg_mask_in_mask_range:
   "is_aligned ptr bits \<Longrightarrow> (ptr' && ~~(mask bits) = ptr) = (ptr' \<in> mask_range ptr bits)"
   apply (erule is_aligned_get_word_bits)
    apply (rule iffI)
     apply (drule sym)
     apply (simp add: word_and_le2)
     apply (subst word_plus_and_or_coroll, word_eqI_solve)
     apply (metis le_word_or2 neg_mask_add_mask and.right_idem)
    apply clarsimp
    apply (smt add.right_neutral eq_iff is_aligned_neg_mask_eq mask_out_add_aligned neg_mask_mono_le
               word_and_not)
   apply (simp add: power_overflow mask_eq_decr_exp)
   done
 
 lemma aligned_offset_in_range:
   "\<lbrakk> is_aligned (x :: 'a :: len word) m; y < 2 ^ m; is_aligned p n; n \<ge> m; n < LENGTH('a) \<rbrakk>
    \<Longrightarrow> (x + y \<in> {p .. p + mask n}) = (x \<in> mask_range p n)"
   apply (simp only: is_aligned_add_or flip: neg_mask_in_mask_range)
   by (metis less_mask_eq mask_subsume)
 
 lemma mask_range_to_bl':
   "\<lbrakk> is_aligned (ptr :: 'a :: len word) bits; bits < LENGTH('a) \<rbrakk>
    \<Longrightarrow> mask_range ptr bits
        = {x. take (LENGTH('a) - bits) (to_bl x) = take (LENGTH('a) - bits) (to_bl ptr)}"
   apply (rule set_eqI, rule iffI)
    apply clarsimp
    apply (subgoal_tac "\<exists>y. x = ptr + y \<and> y < 2 ^ bits")
     apply clarsimp
     apply (subst is_aligned_add_conv)
        apply assumption
       apply simp
     apply simp
    apply (rule_tac x="x - ptr" in exI)
    apply (simp add: add_diff_eq[symmetric])
    apply (simp only: word_less_sub_le[symmetric])
    apply (rule word_diff_ls')
     apply (simp add: field_simps mask_eq_decr_exp)
    apply assumption
   apply simp
   apply (subgoal_tac "\<exists>y. y < 2 ^ bits \<and> to_bl (ptr + y) = to_bl x")
    apply clarsimp
    apply (rule conjI)
     apply (erule(1) is_aligned_no_wrap')
    apply (simp only: add_diff_eq[symmetric] mask_eq_decr_exp)
    apply (rule word_plus_mono_right)
     apply simp
    apply (erule is_aligned_no_wrap')
    apply simp
   apply (rule_tac x="of_bl (drop (LENGTH('a) - bits) (to_bl x))" in exI)
   apply (rule context_conjI)
    apply (rule order_less_le_trans [OF of_bl_length])
     apply simp
    apply simp
   apply (subst is_aligned_add_conv)
      apply assumption
     apply simp
   apply (drule sym)
   apply (simp add: word_rep_drop)
   done
 
 lemma mask_range_to_bl:
   "is_aligned (ptr :: 'a :: len word) bits
    \<Longrightarrow> mask_range ptr bits
         = {x. take (LENGTH('a) - bits) (to_bl x) = take (LENGTH('a) - bits) (to_bl ptr)}"
   apply (erule is_aligned_get_word_bits)
    apply (erule(1) mask_range_to_bl')
   apply (rule set_eqI)
   apply (simp add: power_overflow mask_eq_decr_exp)
   done
 
 lemma aligned_mask_range_cases:
   "\<lbrakk> is_aligned (p :: 'a :: len word) n; is_aligned (p' :: 'a :: len word) n' \<rbrakk>
    \<Longrightarrow> mask_range p n \<inter> mask_range p' n' = {} \<or>
        mask_range p n \<subseteq> mask_range p' n' \<or>
        mask_range p n \<supseteq> mask_range p' n'"
   apply (simp add: mask_range_to_bl)
   apply (rule Meson.disj_comm, rule disjCI)
   apply (erule nonemptyE)
   apply simp
   apply (subgoal_tac "(\<exists>n''. LENGTH('a) - n = (LENGTH('a) - n') + n'')
                     \<or> (\<exists>n''. LENGTH('a) - n' = (LENGTH('a) - n) + n'')")
    apply (fastforce simp: take_add)
   apply arith
   done
 
 lemma aligned_mask_range_offset_subset:
   assumes al: "is_aligned (ptr :: 'a :: len word) sz" and al': "is_aligned x sz'"
   and szv: "sz' \<le> sz"
   and xsz: "x < 2 ^ sz"
   shows "mask_range (ptr+x) sz' \<subseteq> mask_range ptr sz"
   using al
 proof (rule is_aligned_get_word_bits)
   assume p0: "ptr = 0" and szv': "LENGTH ('a) \<le> sz"
   then have "(2 ::'a word) ^ sz = 0" by simp
   show ?thesis using p0
     by (simp add: \<open>2 ^ sz = 0\<close> mask_eq_decr_exp)
 next
   assume szv': "sz < LENGTH('a)"
 
   hence blah: "2 ^ (sz - sz') < (2 :: nat) ^ LENGTH('a)"
     using szv by auto
   show ?thesis using szv szv'
     apply (intro range_subsetI)
      apply (rule is_aligned_no_wrap' [OF al xsz])
     apply (simp only: flip: add_diff_eq add_mask_fold)
     apply (subst add.assoc, rule word_plus_mono_right)
      using al' is_aligned_add_less_t2n xsz
      apply fastforce
     apply (simp add: field_simps szv al is_aligned_no_overflow)
     done
 qed
 
 lemma aligned_mask_diff:
   "\<lbrakk> is_aligned (dest :: 'a :: len word) bits; is_aligned (ptr :: 'a :: len word) sz;
      bits \<le> sz; sz < LENGTH('a); dest < ptr \<rbrakk>
    \<Longrightarrow> mask bits + dest < ptr"
   apply (frule_tac p' = ptr in aligned_mask_range_cases, assumption)
   apply (elim disjE)
     apply (drule_tac is_aligned_no_overflow_mask, simp)+
     apply (simp add: algebra_split_simps word_le_not_less)
    apply (drule is_aligned_no_overflow_mask; fastforce)
   by (simp add: aligned_add_mask_less_eq is_aligned_weaken algebra_split_simps)
 
 lemma aligned_mask_ranges_disjoint:
   "\<lbrakk> is_aligned (p :: 'a :: len word) n; is_aligned (p' :: 'a :: len word) n';
      p && ~~(mask n') \<noteq> p'; p' && ~~(mask n) \<noteq> p \<rbrakk>
    \<Longrightarrow> mask_range p n \<inter> mask_range p' n' = {}"
   using aligned_mask_range_cases
   by (auto simp: neg_mask_in_mask_range)
 
 lemma aligned_mask_ranges_disjoint2:
   "\<lbrakk> is_aligned p n; is_aligned ptr bits; n \<ge> m; n < size p; m \<le> bits;
      (\<forall>y < 2 ^ (n - m). p + (y << m) \<notin> mask_range ptr bits) \<rbrakk>
    \<Longrightarrow> mask_range p n \<inter> mask_range ptr bits = {}"
   apply safe
   apply (simp only: flip: neg_mask_in_mask_range)
   apply (drule_tac x="x && mask n >> m" in spec)
   apply (clarsimp simp: shiftr_less_t2n and_mask_less_size wsst_TYs multiple_mask_trivia
                         word_bw_assocs neg_mask_twice max_absorb2 shiftr_shiftl1)
   done
 
 lemma leq_mask_shift:
   "(x :: 'a :: len word) \<le> mask (low_bits + high_bits) \<Longrightarrow> (x >> low_bits) \<le> mask high_bits"
   by (simp add: le_mask_iff shiftr_shiftr)
 
 lemma ucast_ucast_eq_mask_shift:
   "(x :: 'a :: len word) \<le> mask (low_bits + LENGTH('b))
    \<Longrightarrow> ucast((ucast (x >> low_bits)) :: 'b :: len word) = x >> low_bits"
   by (meson and_mask_eq_iff_le_mask eq_ucast_ucast_eq not_le_imp_less shiftr_less_t2n'
             ucast_ucast_len)
 
 lemma const_le_unat:
   "\<lbrakk> b < 2 ^ LENGTH('a); of_nat b \<le> a \<rbrakk> \<Longrightarrow> b \<le> unat (a :: 'a :: len word)"
   apply (simp add: word_le_def)
   apply (simp only: uint_nat zle_int)
   apply transfer
   apply (simp add: take_bit_nat_eq_self)
   done
 
 lemma upt_enum_offset_trivial:
   "\<lbrakk> x < 2 ^ LENGTH('a) - 1 ; n \<le> unat x \<rbrakk>
    \<Longrightarrow> ([(0 :: 'a :: len word) .e. x] ! n) = of_nat n"
   apply (induct x arbitrary: n)
     apply simp
   by (simp add: upto_enum_word_nth)
 
 lemma word_le_mask_out_plus_2sz:
   "x \<le> (x && ~~(mask sz)) + 2 ^ sz - 1"
   by (metis add_diff_eq word_neg_and_le)
 
 lemma ucast_add:
   "ucast (a + (b :: 'a :: len word)) = ucast a + (ucast b :: ('a signed word))"
   by transfer (simp add: take_bit_add)
 
 lemma ucast_minus:
   "ucast (a - (b :: 'a :: len word)) = ucast a - (ucast b :: ('a signed word))"
   apply (insert ucast_add[where a=a and b="-b"])
   apply (metis (no_types, hide_lams) add_diff_eq diff_add_cancel ucast_add)
   done
 
 lemma scast_ucast_add_one [simp]:
   "scast (ucast (x :: 'a::len word) + (1 :: 'a signed word)) = x + 1"
   apply (subst ucast_1[symmetric])
   apply (subst ucast_add[symmetric])
   apply clarsimp
   done
 
 lemma word_and_le_plus_one:
   "a > 0 \<Longrightarrow> (x :: 'a :: len word) && (a - 1) < a"
   by (simp add: gt0_iff_gem1 word_and_less')
 
 lemma unat_of_ucast_then_shift_eq_unat_of_shift[simp]:
   "LENGTH('b) \<ge> LENGTH('a)
    \<Longrightarrow> unat ((ucast (x :: 'a :: len word) :: 'b :: len word) >> n) = unat (x >> n)"
   by (simp add: shiftr_div_2n' unat_ucast_up_simp)
 
 lemma unat_of_ucast_then_mask_eq_unat_of_mask[simp]:
   "LENGTH('b) \<ge> LENGTH('a)
    \<Longrightarrow> unat ((ucast (x :: 'a :: len word) :: 'b :: len word) && mask m) = unat (x && mask m)"
   by (metis ucast_and_mask unat_ucast_up_simp)
 
 lemma small_powers_of_2:
   "x \<ge> 3 \<Longrightarrow> x < 2 ^ (x - 1)"
   by (induct x; simp add: suc_le_pow_2)
 
 lemma word_clz_sint_upper[simp]:
   "LENGTH('a) \<ge> 3 \<Longrightarrow> sint (of_nat (word_clz (w :: 'a :: len word)) :: 'a sword) \<le> int (LENGTH('a))"
   using small_powers_of_2
   by (smt One_nat_def diff_less le_less_trans len_gt_0 len_signed lessI n_less_equal_power_2
            not_msb_from_less of_nat_mono sint_eq_uint uint_nat unat_of_nat_eq unat_power_lower
            word_clz_max word_of_nat_less wsst_TYs(3))
 
 lemma word_clz_sint_lower[simp]:
   "LENGTH('a) \<ge> 3
    \<Longrightarrow> - sint (of_nat (word_clz (w :: 'a :: len word)) :: 'a signed word) \<le> int (LENGTH('a))"
   apply (subst sint_eq_uint)
    using small_powers_of_2 uint_nat
    apply (simp add: order_le_less_trans[OF word_clz_max] not_msb_from_less word_of_nat_less
                     word_size)
   by (simp add: uint_nat)
 
 lemma shiftr_less_t2n3:
   "\<lbrakk> (2 :: 'a word) ^ (n + m) = 0; m < LENGTH('a) \<rbrakk>
    \<Longrightarrow> (x :: 'a :: len word) >> n < 2 ^ m"
   by (fastforce intro: shiftr_less_t2n' simp: mask_eq_decr_exp power_overflow)
 
 lemma unat_shiftr_le_bound:
   "\<lbrakk> 2 ^ (LENGTH('a :: len) - n) - 1 \<le> bnd; 0 < n \<rbrakk>
    \<Longrightarrow> unat ((x :: 'a word) >> n) \<le> bnd"
   using less_not_refl3 le_step_down_nat le_trans less_or_eq_imp_le word_shiftr_lt
   by (metis (no_types, lifting))
 
 lemma shiftr_eqD:
   "\<lbrakk> x >> n = y >> n; is_aligned x n; is_aligned y n \<rbrakk>
    \<Longrightarrow> x = y"
   by (metis is_aligned_shiftr_shiftl)
 
 lemma word_shiftr_shiftl_shiftr_eq_shiftr:
   "a \<ge> b \<Longrightarrow> (x :: 'a :: len word) >> a << b >> b = x >> a"
   by (simp add: mask_shift multi_shift_simps(5) shiftr_shiftr)
 
 lemma of_int_uint_ucast:
    "of_int (uint (x :: 'a::len word)) = (ucast x :: 'b::len word)"
   by (fact Word.of_int_uint)
 
 lemma mod_mask_drop:
   "\<lbrakk> m = 2 ^ n; 0 < m; mask n && msk = mask n \<rbrakk>
    \<Longrightarrow> (x mod m) && msk = x mod m"
   by (simp add: word_mod_2p_is_mask word_bw_assocs)
 
 lemma mask_eq_ucast_eq:
   "\<lbrakk> x && mask LENGTH('a) = (x :: ('c :: len word));
      LENGTH('a) \<le> LENGTH('b)\<rbrakk>
     \<Longrightarrow> ucast (ucast x :: ('a :: len word)) = (ucast x :: ('b :: len word))"
   by (metis ucast_and_mask ucast_id ucast_ucast_mask ucast_up_eq)
 
 lemma of_nat_less_t2n:
   "of_nat i < (2 :: ('a :: len) word) ^ n \<Longrightarrow> n < LENGTH('a) \<and> unat (of_nat i :: 'a word) < 2 ^ n"
   by (metis order_less_trans p2_gt_0 unat_less_power word_neq_0_conv)
 
 lemma two_power_increasing_less_1:
   "\<lbrakk> n \<le> m; m \<le> LENGTH('a) \<rbrakk> \<Longrightarrow> (2 :: 'a :: len word) ^ n - 1 \<le> 2 ^ m - 1"
   by (metis diff_diff_cancel le_m1_iff_lt less_imp_diff_less p2_gt_0 two_power_increasing
             word_1_le_power word_le_minus_mono_left word_less_sub_1)
 
 lemma word_sub_mono4:
   "\<lbrakk> y + x \<le> z + x; y \<le> y + x; z \<le> z + x \<rbrakk> \<Longrightarrow> y \<le> z" for y :: "'a :: len word"
   by (simp add: word_add_le_iff2)
 
 lemma eq_or_less_helperD:
   "\<lbrakk> n = unat (2 ^ m - 1 :: 'a :: len word) \<or> n < unat (2 ^ m - 1 :: 'a word); m < LENGTH('a) \<rbrakk>
    \<Longrightarrow> n < 2 ^ m"
   by (meson le_less_trans nat_less_le unat_less_power word_power_less_1)
 
 lemma mask_sub:
   "n \<le> m \<Longrightarrow> mask m - mask n = mask m && ~~(mask n)"
   by (metis (full_types) and_mask_eq_iff_shiftr_0 mask_out_sub_mask shiftr_mask_le word_bw_comms(1))
 
 lemma neg_mask_diff_bound:
   "sz'\<le> sz \<Longrightarrow> (ptr && ~~(mask sz')) - (ptr && ~~(mask sz)) \<le> 2 ^ sz - 2 ^ sz'"
   (is "_ \<Longrightarrow> ?lhs \<le> ?rhs")
 proof -
   assume lt: "sz' \<le> sz"
   hence "?lhs = ptr && (mask sz && ~~(mask sz'))"
     by (metis add_diff_cancel_left' multiple_mask_trivia)
   also have "\<dots> \<le> ?rhs" using lt
     by (metis (mono_tags) add_diff_eq diff_eq_eq eq_iff mask_2pm1 mask_sub word_and_le')
   finally show ?thesis by simp
 qed
 
 lemma mask_range_subsetD:
   "\<lbrakk> p' \<in> mask_range p n; x' \<in> mask_range p' n'; n' \<le> n; is_aligned p n; is_aligned p' n' \<rbrakk> \<Longrightarrow>
    x' \<in> mask_range p n"
   using aligned_mask_step by fastforce
 
 lemma add_mult_in_mask_range:
   "\<lbrakk> is_aligned (base :: 'a :: len word) n; n < LENGTH('a); bits \<le> n; x < 2 ^ (n - bits) \<rbrakk>
    \<Longrightarrow> base + x * 2^bits \<in> mask_range base n"
   by (simp add: is_aligned_no_wrap' mask_2pm1 nasty_split_lt word_less_power_trans2
                 word_plus_mono_right)
 
 lemma of_bl_length2:
   "length xs + c < LENGTH('a) \<Longrightarrow> of_bl xs * 2^c < (2::'a::len word) ^ (length xs + c)"
   by (simp add: of_bl_length word_less_power_trans2)
 
 lemma mask_out_eq_0:
   "\<lbrakk> idx < 2 ^ sz; sz < LENGTH('a) \<rbrakk> \<Longrightarrow> (of_nat idx :: 'a :: len word) && ~~(mask sz) = 0"
   by (simp add: Word_Lemmas.of_nat_power less_mask_eq mask_eq_0_eq_x)
 
 lemma is_aligned_neg_mask_eq':
   "is_aligned ptr sz = (ptr && ~~(mask sz) = ptr)"
   using is_aligned_mask mask_eq_0_eq_x by blast
 
 lemma neg_mask_mask_unat:
   "sz < LENGTH('a)
    \<Longrightarrow> unat ((ptr :: 'a :: len word) && ~~(mask sz)) + unat (ptr && mask sz) = unat ptr"
   by (metis AND_NOT_mask_plus_AND_mask_eq unat_plus_simple word_and_le2)
 
 lemma unat_pow_le_intro:
   "LENGTH('a) \<le> n \<Longrightarrow> unat (x :: 'a :: len word) < 2 ^ n"
   by (metis lt2p_lem not_le of_nat_le_iff of_nat_numeral semiring_1_class.of_nat_power uint_nat)
 
 lemma unat_shiftl_less_t2n:
   "\<lbrakk> unat (x :: 'a :: len word) < 2 ^ (m - n); m < LENGTH('a) \<rbrakk> \<Longrightarrow> unat (x << n) < 2 ^ m"
   by (metis (no_types) Word_Lemmas.of_nat_power diff_le_self le_less_trans shiftl_less_t2n
                        unat_less_power word_unat.Rep_inverse)
 
 lemma unat_is_aligned_add:
   "\<lbrakk> is_aligned p n; unat d < 2 ^ n \<rbrakk>
    \<Longrightarrow> unat (p + d && mask n) = unat d \<and> unat (p + d && ~~(mask n)) = unat p"
   by (metis add.right_neutral and_mask_eq_iff_le_mask and_not_mask le_mask_iff mask_add_aligned
             mask_out_add_aligned mult_zero_right shiftl_t2n shiftr_le_0)
 
 lemma unat_shiftr_shiftl_mask_zero:
   "\<lbrakk> c + a \<ge> LENGTH('a) + b ; c < LENGTH('a) \<rbrakk>
    \<Longrightarrow> unat (((q :: 'a :: len word) >> a << b) && ~~(mask c)) = 0"
   by (fastforce intro: unat_is_aligned_add[where p=0 and n=c, simplified, THEN conjunct2]
                        unat_shiftl_less_t2n unat_shiftr_less_t2n unat_pow_le_intro)
 
 lemmas of_nat_ucast = ucast_of_nat[symmetric]
 
 lemma shift_then_mask_eq_shift_low_bits:
   "x \<le> mask (low_bits + high_bits) \<Longrightarrow> (x >> low_bits) && mask high_bits = x >> low_bits"
   by (simp add: leq_mask_shift le_mask_imp_and_mask)
 
 lemma leq_low_bits_iff_zero:
   "\<lbrakk> x \<le> mask (low bits + high bits); x >> low_bits = 0 \<rbrakk> \<Longrightarrow> (x && mask low_bits = 0) = (x = 0)"
   using and_mask_eq_iff_shiftr_0 by force
 
 lemma unat_less_iff:
   "\<lbrakk> unat (a :: 'a :: len word) = b; c < 2 ^ LENGTH('a) \<rbrakk> \<Longrightarrow> (a < of_nat c) = (b < c)"
   using unat_ucast_less_no_overflow_simp by blast
 
 lemma is_aligned_no_overflow3:
  "\<lbrakk> is_aligned (a :: 'a :: len word) n; n < LENGTH('a); b < 2 ^ n; c \<le> 2 ^ n; b < c \<rbrakk>
   \<Longrightarrow> a + b \<le> a + (c - 1)"
   by (meson is_aligned_no_wrap' le_m1_iff_lt not_le word_less_sub_1 word_plus_mono_right)
 
 lemma mask_add_aligned_right:
   "is_aligned p n \<Longrightarrow> (q + p) && mask n = q && mask n"
   by (simp add: mask_add_aligned add.commute)
 
 lemma leq_high_bits_shiftr_low_bits_leq_bits_mask:
   "x \<le> mask high_bits \<Longrightarrow> (x :: 'a :: len word) << low_bits \<le> mask (low_bits + high_bits)"
   by (metis le_mask_shiftl_le_mask)
 
 lemma from_to_bool_last_bit:
   "from_bool (to_bool (x && 1)) = x && 1"
   by (metis from_bool_to_bool_iff word_and_1)
 
 lemma word_two_power_neg_ineq:
   "2 ^ m \<noteq> (0 :: 'a word) \<Longrightarrow> 2 ^ n \<le> - (2 ^ m :: 'a :: len word)"
   apply (cases "n < LENGTH('a)"; simp add: power_overflow)
   apply (cases "m < LENGTH('a)"; simp add: power_overflow)
   apply (simp add: word_le_nat_alt unat_minus word_size)
   apply (cases "LENGTH('a)"; simp)
   apply (simp add: less_Suc_eq_le)
   apply (drule power_increasing[where a=2 and n=n] power_increasing[where a=2 and n=m], simp)+
   apply (drule(1) add_le_mono)
   apply simp
   done
 
 lemma unat_shiftl_absorb:
   "\<lbrakk> x \<le> 2 ^ p; p + k < LENGTH('a) \<rbrakk> \<Longrightarrow> unat (x :: 'a :: len word) * 2 ^ k = unat (x * 2 ^ k)"
   by (smt add_diff_cancel_right' add_lessD1 le_add2 le_less_trans mult.commute nat_le_power_trans
           unat_lt2p unat_mult_lem unat_power_lower word_le_nat_alt)
 
 lemma word_plus_mono_right_split:
   "\<lbrakk> unat ((x :: 'a :: len word) && mask sz) + unat z < 2 ^ sz; sz < LENGTH('a) \<rbrakk>
    \<Longrightarrow> x \<le> x + z"
   apply (subgoal_tac "(x && ~~(mask sz)) + (x && mask sz) \<le> (x && ~~(mask sz)) + ((x && mask sz) + z)")
    apply (simp add:word_plus_and_or_coroll2 field_simps)
   apply (rule word_plus_mono_right)
    apply (simp add: less_le_trans no_olen_add_nat)
   using Word_Lemmas.of_nat_power is_aligned_no_wrap' by force
 
 lemma mul_not_mask_eq_neg_shiftl:
   "~~(mask n) = -1 << n"
   by (simp add: NOT_mask shiftl_t2n)
 
 lemma shiftr_mul_not_mask_eq_and_not_mask:
   "(x >> n) * ~~(mask n) = - (x && ~~(mask n))"
   by (metis NOT_mask and_not_mask mult_minus_left semiring_normalization_rules(7) shiftl_t2n)
 
 lemma mask_eq_n1_shiftr:
   "n \<le> LENGTH('a) \<Longrightarrow> (mask n :: 'a :: len word) = -1 >> (LENGTH('a) - n)"
   by (metis diff_diff_cancel eq_refl mask_full shiftr_mask2)
 
 lemma is_aligned_mask_out_add_eq:
   "is_aligned p n \<Longrightarrow> (p + x) && ~~(mask n) = p + (x && ~~(mask n))"
   by (simp add: mask_out_sub_mask mask_add_aligned)
 
 lemmas is_aligned_mask_out_add_eq_sub
     = is_aligned_mask_out_add_eq[where x="a - b" for a b, simplified field_simps]
 
 lemma aligned_bump_down:
   "is_aligned x n \<Longrightarrow> (x - 1) && ~~(mask n) = x - 2 ^ n"
   by (drule is_aligned_mask_out_add_eq[where x="-1"]) (simp add: NOT_mask)
 
 lemma unat_2tp_if:
   "unat (2 ^ n :: ('a :: len) word) = (if n < LENGTH ('a) then 2 ^ n else 0)"
   by (split if_split, simp_all add: power_overflow)
 
 lemma mask_of_mask:
   "mask (n::nat) && mask (m::nat) = mask (min m n)"
   by word_eqI_solve
 
 lemma unat_signed_ucast_less_ucast:
   "LENGTH('a) \<le> LENGTH('b) \<Longrightarrow> unat (ucast (x :: 'a :: len word) :: 'b :: len signed word) = unat x"
   by (simp add: unat_ucast_up_simp)
 
 lemma toEnum_of_ucast:
   "LENGTH('b) \<le> LENGTH('a) \<Longrightarrow>
    (toEnum (unat (b::'b :: len word))::'a :: len word) = of_nat (unat b)"
   by (simp add: unat_pow_le_intro)
 
 lemmas unat_ucast_mask = unat_ucast_eq_unat_and_mask[where w=a for a]
 
 lemma t2n_mask_eq_if:
   "2 ^ n && mask m = (if n < m then 2 ^ n else 0)"
   by (rule word_eqI, auto simp add: word_size nth_w2p split: if_split)
 
 lemma unat_ucast_le:
   "unat (ucast (x :: 'a :: len word) :: 'b :: len word) \<le> unat x"
   by (simp add: ucast_nat_def word_unat_less_le)
 
 lemma ucast_le_up_down_iff:
   "\<lbrakk> LENGTH('a) \<le> LENGTH('b); (x :: 'b :: len word) \<le> ucast (max_word :: 'a :: len word) \<rbrakk>
    \<Longrightarrow> (ucast x \<le> (y :: 'a word)) = (x \<le> ucast y)"
   using le_max_word_ucast_id ucast_le_ucast by metis
 
 lemma ucast_ucast_mask_shift:
   "a \<le> LENGTH('a) + b
    \<Longrightarrow> ucast (ucast (p && mask a >> b) :: 'a :: len word) = p && mask a >> b"
   by (metis add.commute le_mask_iff shiftr_mask_le ucast_ucast_eq_mask_shift word_and_le')
 
 lemma unat_ucast_mask_shift:
   "a \<le> LENGTH('a) + b
    \<Longrightarrow> unat (ucast (p && mask a >> b) :: 'a :: len word) = unat (p && mask a >> b)"
   by (metis linear ucast_ucast_mask_shift unat_ucast_up_simp)
 
 lemma mask_overlap_zero:
   "a \<le> b \<Longrightarrow> (p && mask a) && ~~(mask b) = 0"
   by (metis NOT_mask_AND_mask mask_lower_twice2 max_def)
 
 lemma mask_shifl_overlap_zero:
   "a + c \<le> b \<Longrightarrow> (p && mask a << c) && ~~(mask b) = 0"
   by (metis and_mask_0_iff_le_mask mask_mono mask_shiftl_decompose order_trans shiftl_over_and_dist word_and_le' word_and_le2)
 
 lemma mask_overlap_zero':
   "a \<ge> b \<Longrightarrow> (p && ~~(mask a)) && mask b = 0"
   using mask_AND_NOT_mask mask_AND_less_0 by blast
 
 lemma mask_rshift_mult_eq_rshift_lshift:
   "((a :: 'a :: len word) >> b) * (1 << c) = (a >> b << c)"
   by (simp add: shiftl_t2n)
 
 lemma shift_alignment:
   "a \<ge> b \<Longrightarrow> is_aligned (p >> a << a) b"
   using is_aligned_shift is_aligned_weaken by blast
 
 lemma mask_split_sum_twice:
   "a \<ge> b \<Longrightarrow> (p && ~~(mask a)) + ((p && mask a) && ~~(mask b)) + (p && mask b) = p"
   by (simp add: add.commute multiple_mask_trivia word_bw_comms(1) word_bw_lcs(1) word_plus_and_or_coroll2)
 
 lemma mask_shift_eq_mask_mask:
   "(p && mask a >> b << b) = (p && mask a) && ~~(mask b)"
   by (simp add: and_not_mask)
 
 lemma mask_shift_sum:
   "\<lbrakk> a \<ge> b; unat n = unat (p && mask b) \<rbrakk>
    \<Longrightarrow> (p && ~~(mask a)) + (p && mask a >> b) * (1 << b) + n = (p :: 'a :: len word)"
   by (metis and_not_mask mask_rshift_mult_eq_rshift_lshift mask_split_sum_twice word_unat.Rep_eqD)
 
 lemma is_up_compose:
   "\<lbrakk> is_up uc; is_up uc' \<rbrakk> \<Longrightarrow> is_up (uc' \<circ> uc)"
   unfolding is_up_def by (simp add: Word.target_size Word.source_size)
 
 lemma of_int_sint_scast:
   "of_int (sint (x :: 'a :: len word)) = (scast x :: 'b :: len word)"
   by (fact Word.of_int_sint) 
 
 lemma scast_of_nat_to_signed [simp]:
   "scast (of_nat x :: 'a :: len word) = (of_nat x :: 'a signed word)"
   by (metis cast_simps(23) scast_scast_id(2))
 
 lemma scast_of_nat_signed_to_unsigned_add:
   "scast (of_nat x + of_nat y :: 'a :: len signed word) = (of_nat x + of_nat y :: 'a :: len word)"
   by (metis of_nat_add scast_of_nat)
 
 lemma scast_of_nat_unsigned_to_signed_add:
   "(scast (of_nat x + of_nat y :: 'a :: len word)) = (of_nat x + of_nat y :: 'a :: len signed word)"
   by (metis Abs_fnat_hom_add scast_of_nat_to_signed)
 
 lemma and_mask_cases:
   fixes x :: "'a :: len word"
   assumes len: "n < LENGTH('a)"
   shows "x && mask n \<in> of_nat ` set [0 ..< 2 ^ n]"
   apply (simp flip: take_bit_eq_mask)
   apply (rule image_eqI [of _ _ \<open>unat (take_bit n x)\<close>])
   using len apply simp_all
   apply transfer
   apply simp
   done
 
 lemma sint_of_nat_ge_zero:
   "x < 2 ^ (LENGTH('a) - 1) \<Longrightarrow> sint (of_nat x :: 'a :: len word) \<ge> 0"
   by (simp add: bit_iff_odd)
 
 lemma sint_eq_uint_2pl:
   "\<lbrakk> (a :: 'a :: len word) < 2 ^ (LENGTH('a) - 1) \<rbrakk>
    \<Longrightarrow> sint a = uint a"
   by (simp add: not_msb_from_less sint_eq_uint word_2p_lem word_size)
 
 lemma sint_of_nat_le:
   "\<lbrakk> b < 2 ^ (LENGTH('a) - 1); a \<le> b \<rbrakk>
    \<Longrightarrow> sint (of_nat a :: 'a :: len word) \<le> sint (of_nat b :: 'a :: len word)"
   by (smt Word_Lemmas.of_nat_power diff_less le_less_trans len_gt_0 len_of_numeral_defs(2)
           nat_power_minus_less of_nat_le_iff sint_eq_uint_2pl uint_nat unat_of_nat_len)
 
 lemma int_eq_sint:
   "x < 2 ^ (LENGTH('a) - 1) \<Longrightarrow> sint (of_nat x :: 'a :: len word) = int x"
   by (smt Word_Lemmas.of_nat_power diff_less le_less_trans len_gt_0 len_of_numeral_defs(2)
           nat_less_le sint_eq_uint_2pl uint_nat unat_lt2p unat_of_nat_len unat_power_lower)
 
 lemma sint_ctz:
   "LENGTH('a) > 2
    \<Longrightarrow> 0 \<le> sint (of_nat (word_ctz (x :: 'a :: len word)) :: 'a signed word)
         \<and> sint (of_nat (word_ctz x) :: 'a signed word) \<le> int (LENGTH('a))"
   apply (subgoal_tac "LENGTH('a) < 2 ^ (LENGTH('a) - 1)")
    apply (rule conjI)
     apply (metis len_signed order_le_less_trans sint_of_nat_ge_zero word_ctz_le)
    apply (metis int_eq_sint len_signed sint_of_nat_le word_ctz_le)
   by (rule small_powers_of_2, simp)
 
 lemma pow_sub_less:
   "\<lbrakk> a + b \<le> LENGTH('a); unat (x :: 'a :: len word) = 2 ^ a \<rbrakk>
    \<Longrightarrow> unat (x * 2 ^ b - 1) < 2 ^ (a + b)"
   by (metis (mono_tags) eq_or_less_helperD not_less of_nat_numeral power_add
                         semiring_1_class.of_nat_power unat_pow_le_intro word_unat.Rep_inverse)
 
 lemma sle_le_2pl:
   "\<lbrakk> (b :: 'a :: len word) < 2 ^ (LENGTH('a) - 1); a \<le> b \<rbrakk> \<Longrightarrow> a <=s b"
   by (simp add: not_msb_from_less word_sle_msb_le)
 
 lemma sless_less_2pl:
   "\<lbrakk> (b :: 'a :: len word) < 2 ^ (LENGTH('a) - 1); a < b \<rbrakk> \<Longrightarrow> a <s b"
   using not_msb_from_less word_sless_msb_less by blast
 
 lemma and_mask2:
   "w << n >> n = w && mask (size w - n)"
   by (cases "n \<le> size w"; clarsimp simp: word_and_le2 and_mask shiftl_zero_size)
 
 lemma unat_of_nat_word_log2:
   "LENGTH('a) < 2 ^ LENGTH('b)
    \<Longrightarrow> unat (of_nat (word_log2 (n :: 'a :: len word)) :: 'b :: len word) = word_log2 n"
   by (metis less_trans unat_of_nat_eq word_log2_max word_size)
 
 lemma aligned_sub_aligned_simple:
   "\<lbrakk> is_aligned a n; is_aligned b n \<rbrakk> \<Longrightarrow> is_aligned (a - b) n"
   by (simp add: aligned_sub_aligned)
 
 lemma minus_one_shift:
   "- (1 << n) = (-1 << n :: 'a::len word)"
   by (simp add: mask_eq_decr_exp NOT_eq flip: mul_not_mask_eq_neg_shiftl)
 
 lemma ucast_eq_mask:
   "(UCAST('a::len \<rightarrow> 'b::len) x = UCAST('a \<rightarrow> 'b) y) =
    (x && mask LENGTH('b) = y && mask LENGTH('b))"
   by (rule iffI; word_eqI_solve)
 
 context
   fixes w :: "'a::len word"
 begin
 
 private lemma sbintrunc_uint_ucast:
   assumes "Suc n = LENGTH('b::len)"
   shows "sbintrunc n (uint (ucast w :: 'b word)) = sbintrunc n (uint w)"
   by (metis assms sbintrunc_bintrunc ucast_eq word_ubin.eq_norm)
 
 private lemma test_bit_sbintrunc:
   assumes "i < LENGTH('a)"
   shows "(word_of_int (sbintrunc n (uint w)) :: 'a word) !! i
            = (if n < i then w !! n else w !! i)"
   using assms by (simp add: nth_sbintr)
                  (simp add: test_bit_bin)
 
 private lemma test_bit_sbintrunc_ucast:
   assumes len_a: "i < LENGTH('a)"
   shows "(word_of_int (sbintrunc (LENGTH('b) - 1) (uint (ucast w :: 'b word))) :: 'a word) !! i
           = (if LENGTH('b::len) \<le> i then w !! (LENGTH('b) - 1) else w !! i)"
   apply (subst sbintrunc_uint_ucast)
    apply simp
   apply (subst test_bit_sbintrunc)
    apply (rule len_a)
   apply (rule if_cong[OF _ refl refl])
   using leD less_linear by fastforce
 
 lemma scast_ucast_high_bits:
   \<open>scast (ucast w :: 'b::len word) = w
      \<longleftrightarrow> (\<forall> i \<in> {LENGTH('b) ..< size w}. w !! i = w !! (LENGTH('b) - 1))\<close>
 proof (cases \<open>LENGTH('a) \<le> LENGTH('b)\<close>)
   case True
   moreover define m where \<open>m = LENGTH('b) - LENGTH('a)\<close>
   ultimately have \<open>LENGTH('b) = m + LENGTH('a)\<close>
     by simp
   then show ?thesis
     apply (simp_all add: signed_ucast_eq word_size)
     apply (rule bit_word_eqI)
     apply (simp add: bit_signed_take_bit_iff)
     done
 next
   case False
   define q where \<open>q = LENGTH('b) - 1\<close>
   then have \<open>LENGTH('b) = Suc q\<close>
     by simp
   moreover define m where \<open>m = Suc LENGTH('a) - LENGTH('b)\<close>
   with False \<open>LENGTH('b) = Suc q\<close> have \<open>LENGTH('a) = m + q\<close>
     by (simp add: not_le)
   ultimately show ?thesis
     apply (simp_all add: signed_ucast_eq word_size)
     apply (transfer fixing: m q)
     apply (simp add: signed_take_bit_take_bit)
     apply rule
     apply (subst bit_eq_iff)
     apply (simp add: bit_take_bit_iff bit_signed_take_bit_iff min_def)
     apply (auto simp add: Suc_le_eq)
     using less_imp_le_nat apply blast
     using less_imp_le_nat apply blast
     done
 qed
   
 lemma scast_ucast_mask_compare:
   "scast (ucast w :: 'b::len word) = w
    \<longleftrightarrow> (w \<le> mask (LENGTH('b) - 1) \<or> ~~(mask (LENGTH('b) - 1)) \<le> w)"
   apply (clarsimp simp: le_mask_high_bits neg_mask_le_high_bits scast_ucast_high_bits word_size)
   apply (rule iffI; clarsimp)
    apply (rename_tac i j; case_tac "i = LENGTH('b) - 1"; case_tac "j = LENGTH('b) - 1")
   by auto
 
 lemma ucast_less_shiftl_helper':
   "\<lbrakk> LENGTH('b) + (a::nat) < LENGTH('a); 2 ^ (LENGTH('b) + a) \<le> n\<rbrakk>
    \<Longrightarrow> (ucast (x :: 'b::len word) << a) < (n :: 'a::len word)"
   apply (erule order_less_le_trans[rotated])
   using ucast_less[where x=x and 'a='a]
   apply (simp only: shiftl_t2n field_simps)
   apply (rule word_less_power_trans2; simp)
   done
 
 end
 
 lemma ucast_ucast_mask2:
   "is_down (UCAST ('a \<rightarrow> 'b)) \<Longrightarrow>
    UCAST ('b::len \<rightarrow> 'c::len) (UCAST ('a::len \<rightarrow> 'b::len) x) = UCAST ('a \<rightarrow> 'c) (x && mask LENGTH('b))"
   by word_eqI_solve
 
 lemma ucast_NOT:
   "ucast (~~x) = ~~(ucast x) && mask (LENGTH('a))" for x::"'a::len word"
   by word_eqI
 
 lemma ucast_NOT_down:
   "is_down UCAST('a::len \<rightarrow> 'b::len) \<Longrightarrow> UCAST('a \<rightarrow> 'b) (~~x) = ~~(UCAST('a \<rightarrow> 'b) x)"
   by word_eqI
 
 lemma of_bl_mult_and_not_mask_eq:
   "\<lbrakk>is_aligned (a :: 'a::len word) n; length b + m \<le> n\<rbrakk>
    \<Longrightarrow> a + of_bl b * (2^m) && ~~(mask n) = a"
   by (smt add.left_neutral add_diff_cancel_right' add_mask_lower_bits and_mask_plus is_aligned_mask
           is_aligned_weaken le_less_trans of_bl_length2 subtract_mask(1))
 
 lemma bin_to_bl_of_bl_eq:
   "\<lbrakk>is_aligned (a::'a::len word) n; length b + c \<le> n; length b + c < LENGTH('a)\<rbrakk>
   \<Longrightarrow> bin_to_bl (length b) (uint ((a + of_bl b * 2^c) >> c)) = b"
   apply (subst word_plus_and_or_coroll)
    apply (erule is_aligned_get_word_bits)
     apply (rule is_aligned_AND_less_0)
      apply (simp add: is_aligned_mask)
     apply (rule order_less_le_trans)
      apply (rule of_bl_length2)
      apply simp
     apply (simp add: two_power_increasing)
    apply simp
   apply (rule nth_equalityI)
    apply (simp only: len_bin_to_bl)
   apply (clarsimp simp only: len_bin_to_bl nth_bin_to_bl word_test_bit_def[symmetric])
   apply (simp add: nth_shiftr nth_shiftl
                    shiftl_t2n[where n=c, simplified mult.commute, simplified, symmetric])
   apply (simp add: is_aligned_nth[THEN iffD1, rule_format] test_bit_of_bl rev_nth)
   apply arith
   done
 
 end
diff --git a/thys/Word_Lib/Word_Lib.thy b/thys/Word_Lib/Word_Lib.thy
--- a/thys/Word_Lib/Word_Lib.thy
+++ b/thys/Word_Lib/Word_Lib.thy
@@ -1,731 +1,743 @@
 (*
  * Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 section "Additional Word Operations"
 
 theory Word_Lib
-imports
-  "HOL-Word.Misc_set_bit" Word_Syntax
+  imports
+  "HOL-Library.Signed_Division"
+  "HOL-Word.Misc_set_bit"
+  Word_Syntax
 begin
 
 definition
   ptr_add :: "'a :: len word \<Rightarrow> nat \<Rightarrow> 'a word" where
   "ptr_add ptr n \<equiv> ptr + of_nat n"
 
 definition
   complement :: "'a :: len word \<Rightarrow> 'a word"  where
  "complement x \<equiv> ~~ x"
 
 definition
   alignUp :: "'a::len word \<Rightarrow> nat \<Rightarrow> 'a word" where
  "alignUp x n \<equiv> x + 2 ^ n - 1 && complement (2 ^ n - 1)"
 
 (* standard notation for blocks of 2^n-1 words, usually aligned;
    abbreviation so it simplifies directly *)
 abbreviation mask_range :: "'a::len word \<Rightarrow> nat \<Rightarrow> 'a word set" where
   "mask_range p n \<equiv> {p .. p + mask n}"
 
 (* Haskellish names/syntax *)
 notation (input)
   test_bit ("testBit")
 
 definition
   w2byte :: "'a :: len word \<Rightarrow> 8 word" where
   "w2byte \<equiv> ucast"
 
+lemmas sdiv_int_def = signed_divide_int_def
+lemmas smod_int_def = signed_modulo_int_def
 
-(*
- * Signed division: when the result of a division is negative,
- * we will round towards zero instead of towards minus infinity.
- *)
-class signed_div =
-  fixes sdiv :: "'a \<Rightarrow> 'a \<Rightarrow> 'a" (infixl "sdiv" 70)
-  fixes smod :: "'a \<Rightarrow> 'a \<Rightarrow> 'a" (infixl "smod" 70)
+instantiation word :: (len) signed_division
+begin
 
-instantiation int :: signed_div
-begin
-definition "(a :: int) sdiv b \<equiv> sgn (a * b) * (abs a div abs b)"
-definition "(a :: int) smod b \<equiv> a - (a sdiv b) * b"
+lift_definition signed_divide_word :: \<open>'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>
+  is \<open>\<lambda>k l. signed_take_bit (LENGTH('a) - Suc 0) k sdiv signed_take_bit (LENGTH('a) - Suc 0) l\<close>
+  by (simp flip: signed_take_bit_decr_length_iff)
+
+lift_definition signed_modulo_word :: \<open>'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>
+  is \<open>\<lambda>k l. signed_take_bit (LENGTH('a) - Suc 0) k smod signed_take_bit (LENGTH('a) - Suc 0) l\<close>
+  by (simp flip: signed_take_bit_decr_length_iff)
+
 instance ..
+
 end
 
-instantiation word :: (len) signed_div
-begin
-definition "(a :: ('a::len) word) sdiv b = word_of_int (sint a sdiv sint b)"
-definition "(a :: ('a::len) word) smod b = word_of_int (sint a smod sint b)"
-instance ..
-end
+lemma sdiv_word_def:
+  \<open>v sdiv w = word_of_int (sint v sdiv sint w)\<close>
+  for v w :: \<open>'a::len word\<close>
+  by transfer simp
+
+lemma smod_word_def:
+  \<open>v smod w = word_of_int (sint v smod sint w)\<close>
+  for v w :: \<open>'a::len word\<close>
+  by transfer simp
+
+lemma sdiv_smod_id:
+  \<open>(a sdiv b) * b + (a smod b) = a\<close>
+  for a b :: \<open>'a::len word\<close>
+  by (cases \<open>sint a < 0\<close>; cases \<open>sint b < 0\<close>) (simp_all add: signed_modulo_int_def sdiv_word_def smod_word_def)
 
 (* Tests *)
 lemma
   "( 4 :: word32) sdiv  4 =  1"
   "(-4 :: word32) sdiv  4 = -1"
   "(-3 :: word32) sdiv  4 =  0"
   "( 3 :: word32) sdiv -4 =  0"
   "(-3 :: word32) sdiv -4 =  0"
   "(-5 :: word32) sdiv -4 =  1"
   "( 5 :: word32) sdiv -4 = -1"
-  by (simp_all add: sdiv_word_def sdiv_int_def)
+  by (simp_all add: sdiv_word_def signed_divide_int_def)
 
 lemma
   "( 4 :: word32) smod  4 =   0"
   "( 3 :: word32) smod  4 =   3"
   "(-3 :: word32) smod  4 =  -3"
   "( 3 :: word32) smod -4 =   3"
   "(-3 :: word32) smod -4 =  -3"
   "(-5 :: word32) smod -4 =  -1"
   "( 5 :: word32) smod -4 =   1"
-  by (simp_all add: smod_word_def smod_int_def sdiv_int_def)
+  by (simp_all add: smod_word_def signed_modulo_int_def signed_divide_int_def)
 
 
 (* Count leading zeros  *)
 definition
   word_clz :: "'a::len word \<Rightarrow> nat"
 where
   "word_clz w \<equiv> length (takeWhile Not (to_bl w))"
 
 (* Count trailing zeros  *)
 definition
   word_ctz :: "'a::len word \<Rightarrow> nat"
 where
   "word_ctz w \<equiv> length (takeWhile Not (rev (to_bl w)))"
 
 definition
   word_log2 :: "'a::len word \<Rightarrow> nat"
 where
   "word_log2 (w::'a::len word) \<equiv> size w - 1 - word_clz w"
 
 
 (* Bit population count. Equivalent of __builtin_popcount. *)
 definition
   pop_count :: "('a::len) word \<Rightarrow> nat"
 where
   "pop_count w \<equiv> length (filter id (to_bl w))"
 
 
 (* Sign extension from bit n *)
 
 definition
   sign_extend :: "nat \<Rightarrow> 'a::len word \<Rightarrow> 'a word"
 where
   "sign_extend n w \<equiv> if w !! n then w || ~~ (mask n) else w && mask n"
 
 lemma sign_extend_eq_signed_take_bit:
   \<open>sign_extend = signed_take_bit\<close>
 proof (rule ext)+
   fix n and w :: \<open>'a::len word\<close>
   show \<open>sign_extend n w = signed_take_bit n w\<close>
   proof (rule bit_word_eqI)
     fix q
     assume \<open>q < LENGTH('a)\<close>
     then show \<open>bit (sign_extend n w) q \<longleftrightarrow> bit (signed_take_bit n w) q\<close>
       by (auto simp add: test_bit_eq_bit bit_signed_take_bit_iff
         sign_extend_def bit_and_iff bit_or_iff bit_not_iff bit_mask_iff not_less
         exp_eq_0_imp_not_bit not_le min_def)
   qed
 qed
 
 definition
   sign_extended :: "nat \<Rightarrow> 'a::len word \<Rightarrow> bool"
 where
   "sign_extended n w \<equiv> \<forall>i. n < i \<longrightarrow> i < size w \<longrightarrow> w !! i = w !! n"
 
 
 lemma ptr_add_0 [simp]:
   "ptr_add ref 0 = ref "
   unfolding ptr_add_def by simp
 
 lemma shiftl_power:
   "(shiftl1 ^^ x) (y::'a::len word) = 2 ^ x * y"
   apply (induct x)
    apply simp
   apply (simp add: shiftl1_2t)
   done
 
 lemmas of_bl_reasoning = to_bl_use_of_bl of_bl_append
 
 lemma uint_of_bl_is_bl_to_bin_drop:
   "length (dropWhile Not l) \<le> LENGTH('a) \<Longrightarrow> uint (of_bl l :: 'a::len word) = bl_to_bin l"
   apply transfer
   apply (simp add: take_bit_eq_mod)
   apply (rule Divides.mod_less)
    apply (rule bl_to_bin_ge0)
   using bl_to_bin_lt2p_drop apply (rule order.strict_trans2)
   apply simp
   done
 
 corollary uint_of_bl_is_bl_to_bin:
   "length l\<le>LENGTH('a) \<Longrightarrow> uint ((of_bl::bool list\<Rightarrow> ('a :: len) word) l) = bl_to_bin l"
   apply(rule uint_of_bl_is_bl_to_bin_drop)
   using le_trans length_dropWhile_le by blast
 
 lemma bin_to_bl_or:
   "bin_to_bl n (a OR b) = map2 (\<or>) (bin_to_bl n a) (bin_to_bl n b)"
   using bl_or_aux_bin[where n=n and v=a and w=b and bs="[]" and cs="[]"]
   by simp
 
 lemma word_ops_nth [simp]:
   shows
   word_or_nth:  "(x || y) !! n = (x !! n \<or> y !! n)" and
   word_and_nth: "(x && y) !! n = (x !! n \<and> y !! n)" and
   word_xor_nth: "(x xor y) !! n = (x !! n \<noteq> y !! n)"
   by ((cases "n < size x",
       auto dest: test_bit_size simp: word_ops_nth_size word_size)[1])+
 
 (* simp del to avoid warning on the simp add in iff *)
 declare test_bit_1 [simp del, iff]
 
 (* test: *)
 lemma "1 < (1024::32 word) \<and> 1 \<le> (1024::32 word)" by simp
 
 lemma and_not_mask:
   "w AND NOT (mask n) = (w >> n) << n"
   for w :: \<open>'a::len word\<close>
   apply (rule word_eqI)
   apply (simp add : word_ops_nth_size word_size)
   apply (simp add : nth_shiftr nth_shiftl)
   by auto
 
 lemma and_mask:
   "w AND mask n = (w << (size w - n)) >> (size w - n)"
   for w :: \<open>'a::len word\<close>
   apply (rule word_eqI)
   apply (simp add : word_ops_nth_size word_size)
   apply (simp add : nth_shiftr nth_shiftl)
   by auto
 
 lemma AND_twice [simp]:
   "(w && m) && m = w && m"
   by (simp add: word_eqI)
 
 lemma word_combine_masks:
   "w && m = z \<Longrightarrow> w && m' = z' \<Longrightarrow> w && (m || m') = (z || z')"
   by (auto simp: word_eq_iff)
 
 lemma nth_w2p_same:
   "(2^n :: 'a :: len word) !! n = (n < LENGTH('a))"
   by (simp add : nth_w2p)
 
 lemma p2_gt_0:
   "(0 < (2 ^ n :: 'a :: len word)) = (n < LENGTH('a))"
   apply (simp add : word_gt_0)
   apply safe
    apply (erule swap)
    apply (rule word_eqI)
    apply (simp add : nth_w2p)
   apply (drule word_eqD)
   apply simp
   apply (erule notE)
   apply (erule nth_w2p_same [THEN iffD2])
   done
 
 lemmas uint_2p_alt = uint_2p [unfolded p2_gt_0]
 
 lemma shiftr_div_2n_w: "n < size w \<Longrightarrow> w >> n = w div (2^n :: 'a :: len word)"
   apply (unfold word_div_def)
   apply (simp add : uint_2p_alt word_size)
   apply (rule word_uint.Rep_inverse' [THEN sym])
   apply (rule shiftr_div_2n)
   done
 
 lemmas less_def = less_eq [symmetric]
 lemmas le_def = not_less [symmetric, where ?'a = nat]
 
 lemmas p2_eq_0 [simp] = trans [OF eq_commute
   iffD2 [OF Not_eq_iff p2_gt_0, folded le_def, unfolded word_gt_0 not_not]]
 
 lemma neg_mask_is_div':
   "n < size w \<Longrightarrow> w AND NOT (mask n) = ((w div (2 ^ n)) * (2 ^ n))"
   for w :: \<open>'a::len word\<close>
   by (simp add : and_not_mask shiftr_div_2n_w shiftl_t2n word_size)
 
 lemma neg_mask_is_div:
   "w AND NOT (mask n) = (w div 2^n) * 2^n"
   for w :: \<open>'a::len word\<close>
   apply (cases "n < size w")
    apply (erule neg_mask_is_div')
   apply (simp add: word_size)
   apply (frule p2_gt_0 [THEN Not_eq_iff [THEN iffD2], THEN iffD2])
   apply (simp add: word_gt_0  del: p2_eq_0)
   apply (rule word_eqI)
   apply (simp add: word_ops_nth_size word_size)
   done
 
 lemma and_mask_arith':
   "0 < n \<Longrightarrow> w AND mask n = (w * 2^(size w - n)) div 2^(size w - n)"
   for w :: \<open>'a::len word\<close>
   by (simp add: and_mask shiftr_div_2n_w shiftl_t2n word_size mult.commute)
 
 lemmas p2len = iffD2 [OF p2_eq_0 order_refl]
 
 lemma and_mask_arith:
   "w AND mask n = (w * 2^(size w - n)) div 2^(size w - n)"
   for w :: \<open>'a::len word\<close>
   apply (cases "0 < n")
    apply (auto elim!: and_mask_arith')
   apply (simp add: word_size)
   done
 
 lemma mask_2pm1: "mask n = 2 ^ n - (1 :: 'a::len word)"
   by (fact mask_eq_decr_exp)
 
 lemma add_mask_fold:
   "x + 2 ^ n - 1 = x + mask n"
   for x :: \<open>'a::len word\<close>
   by (simp add: mask_eq_decr_exp)
 
 lemma word_and_mask_le_2pm1: "w && mask n \<le> 2 ^ n - 1"
   by (simp add: mask_2pm1[symmetric] word_and_le1)
 
 lemma is_aligned_AND_less_0:
   "u && mask n = 0 \<Longrightarrow> v < 2^n \<Longrightarrow> u && v = 0"
   apply (drule less_mask_eq)
   apply (simp add: mask_2pm1)
   apply (rule word_eqI)
   apply (clarsimp simp add: word_size)
   apply (drule_tac x=na in word_eqD)
   apply (drule_tac x=na in word_eqD)
   apply simp
   done
 
 lemma le_shiftr1:
   "u <= v \<Longrightarrow> shiftr1 u <= shiftr1 v"
   apply (unfold word_le_def shiftr1_eq word_ubin.eq_norm)
   apply (unfold bin_rest_trunc_i
                 trans [OF bintrunc_bintrunc_l word_ubin.norm_Rep,
                           unfolded word_ubin.norm_Rep,
                        OF order_refl [THEN le_SucI]])
   apply (case_tac "uint u" rule: bin_exhaust)
   apply (rename_tac bs bit)
   apply (case_tac "uint v" rule: bin_exhaust)
   apply (rename_tac bs' bit')
   apply (case_tac "bit")
    apply (case_tac "bit'", auto simp: less_eq_int_code)[1]
   apply (case_tac bit')
     apply (simp add: less_eq_int_code)
   apply (simp add: less_eq_int_code)
   done
 
 lemma le_shiftr:
   "u \<le> v \<Longrightarrow> u >> (n :: nat) \<le> (v :: 'a :: len word) >> n"
   apply (unfold shiftr_def)
   apply (induct_tac "n")
    apply auto
   apply (erule le_shiftr1)
   done
 
 lemma shiftr_mask_le:
   "n <= m \<Longrightarrow> mask n >> m = (0 :: 'a::len word)"
   apply (rule word_eqI)
   apply (simp add: word_size nth_shiftr)
   done
 
 lemmas shiftr_mask = order_refl [THEN shiftr_mask_le, simp]
 
 lemma word_leI:
   "(\<And>n.  \<lbrakk>n < size (u::'a::len word); u !! n \<rbrakk> \<Longrightarrow> (v::'a::len word) !! n) \<Longrightarrow> u <= v"
   apply (rule xtr4)
    apply (rule word_and_le2)
   apply (rule word_eqI)
   apply (simp add: word_ao_nth)
   apply safe
     apply assumption
    apply (erule_tac [2] asm_rl)
   apply (unfold word_size)
   by auto
 
 lemma le_mask_iff:
   "(w \<le> mask n) = (w >> n = 0)"
   for w :: \<open>'a::len word\<close>
   apply safe
    apply (rule word_le_0_iff [THEN iffD1])
    apply (rule xtr3)
     apply (erule_tac [2] le_shiftr)
    apply simp
   apply (rule word_leI)
   apply (rename_tac n')
   apply (drule_tac x = "n' - n" in word_eqD)
   apply (simp add : nth_shiftr word_size)
   apply (case_tac "n <= n'")
   by auto
 
 lemma and_mask_eq_iff_shiftr_0:
   "(w AND mask n = w) = (w >> n = 0)"
   for w :: \<open>'a::len word\<close>
   apply (unfold test_bit_eq_iff [THEN sym])
   apply (rule iffI)
    apply (rule ext)
    apply (rule_tac [2] ext)
    apply (auto simp add : word_ao_nth nth_shiftr)
     apply (drule arg_cong)
     apply (drule iffD2)
      apply assumption
     apply (simp add : word_ao_nth)
    prefer 2
    apply (simp add : word_size test_bit_bin)
   apply (drule_tac f = "%u. u !! (x - n)" in arg_cong)
   apply (simp add : nth_shiftr)
   apply (case_tac "n <= x")
    apply auto
   done
 
 lemmas and_mask_eq_iff_le_mask = trans
   [OF and_mask_eq_iff_shiftr_0 le_mask_iff [THEN sym]]
 
 lemma mask_shiftl_decompose:
   "mask m << n = mask (m + n) && ~~ (mask n)"
   by (auto intro!: word_eqI simp: and_not_mask nth_shiftl nth_shiftr word_size)
 
 lemma one_bit_shiftl: "set_bit 0 n True = (1 :: 'a :: len word) << n"
   apply (rule word_eqI)
   apply (auto simp add: test_bit_set_gen nth_shiftl word_size
               simp del: word_set_bit_0 shiftl_1)
   done
 
 lemmas one_bit_pow = trans [OF one_bit_shiftl shiftl_1]
 
 lemmas bin_sc_minus_simps =
   bin_sc_simps (2,3,4) [THEN [2] trans, OF bin_sc_minus [THEN sym]]
 
 lemma NOT_eq:
   "NOT (x :: 'a :: len word) = - x - 1"
   apply (cut_tac x = "x" in word_add_not)
   apply (drule add.commute [THEN trans])
   apply (drule eq_diff_eq [THEN iffD2])
   by simp
 
 lemma NOT_mask: "NOT (mask n :: 'a::len word) = - (2 ^ n)"
   by (simp add : NOT_eq mask_2pm1)
 
 lemma le_m1_iff_lt: "(x > (0 :: 'a :: len word)) = ((y \<le> x - 1) = (y < x))"
   by uint_arith
 
 lemmas gt0_iff_gem1 = iffD1 [OF iffD1 [OF iff_left_commute le_m1_iff_lt] order_refl]
 
 lemmas power_2_ge_iff = trans [OF gt0_iff_gem1 [THEN sym] p2_gt_0]
 
 lemma le_mask_iff_lt_2n:
   "n < len_of TYPE ('a) = (((w :: 'a :: len word) \<le> mask n) = (w < 2 ^ n))"
   unfolding mask_2pm1 by (rule trans [OF p2_gt_0 [THEN sym] le_m1_iff_lt])
 
 lemmas mask_lt_2pn =
   le_mask_iff_lt_2n [THEN iffD1, THEN iffD1, OF _ order_refl]
 
 lemma bang_eq:
   fixes x :: "'a::len word"
   shows "(x = y) = (\<forall>n. x !! n = y !! n)"
   by (subst test_bit_eq_iff[symmetric]) fastforce
 
 lemma word_unat_power:
   "(2 :: 'a :: len word) ^ n = of_nat (2 ^ n)"
   by simp
 
 lemma of_nat_mono_maybe:
   assumes xlt: "x < 2 ^ len_of TYPE ('a)"
   shows   "y < x \<Longrightarrow> of_nat y < (of_nat x :: 'a :: len word)"
   apply (subst word_less_nat_alt)
   apply (subst unat_of_nat)+
   apply (subst mod_less)
    apply (erule order_less_trans [OF _ xlt])
   apply (subst mod_less [OF xlt])
   apply assumption
   done
 
 lemma shiftl_over_and_dist:
   fixes a::"'a::len word"
   shows "(a AND b) << c = (a << c) AND (b << c)"
   apply(rule word_eqI)
   apply(simp add: word_ao_nth nth_shiftl, safe)
   done
 
 lemma shiftr_over_and_dist:
   fixes a::"'a::len word"
   shows "a AND b >> c = (a >> c) AND (b >> c)"
   apply(rule word_eqI)
   apply(simp add:nth_shiftr word_ao_nth)
   done
 
 lemma sshiftr_over_and_dist:
   fixes a::"'a::len word"
   shows "a AND b >>> c = (a >>> c) AND (b >>> c)"
   apply(rule word_eqI)
   apply(simp add:nth_sshiftr word_ao_nth word_size)
   done
 
 lemma shiftl_over_or_dist:
   fixes a::"'a::len word"
   shows "a OR b << c = (a << c) OR (b << c)"
   apply(rule word_eqI)
   apply(simp add:nth_shiftl word_ao_nth, safe)
   done
 
 lemma shiftr_over_or_dist:
   fixes a::"'a::len word"
   shows "a OR b >> c = (a >> c) OR (b >> c)"
   apply(rule word_eqI)
   apply(simp add:nth_shiftr word_ao_nth)
   done
 
 lemma sshiftr_over_or_dist:
   fixes a::"'a::len word"
   shows "a OR b >>> c = (a >>> c) OR (b >>> c)"
   apply(rule word_eqI)
   apply(simp add:nth_sshiftr word_ao_nth word_size)
   done
 
 lemmas shift_over_ao_dists =
   shiftl_over_or_dist shiftr_over_or_dist
   sshiftr_over_or_dist shiftl_over_and_dist
   shiftr_over_and_dist sshiftr_over_and_dist
 
 lemma shiftl_shiftl:
   fixes a::"'a::len word"
   shows "a << b << c = a << (b + c)"
   apply(rule word_eqI)
   apply(auto simp:word_size nth_shiftl add.commute add.left_commute)
   done
 
 lemma shiftr_shiftr:
   fixes a::"'a::len word"
   shows "a >> b >> c = a >> (b + c)"
   apply(rule word_eqI)
   apply(simp add:word_size nth_shiftr add.left_commute add.commute)
   done
 
 lemma shiftl_shiftr1:
   fixes a::"'a::len word"
   shows "c \<le> b \<Longrightarrow> a << b >> c = a AND (mask (size a - b)) << (b - c)"
   apply(rule word_eqI)
   apply(auto simp:nth_shiftr nth_shiftl word_size word_ao_nth)
   done
 
 lemma shiftl_shiftr2:
   fixes a::"'a::len word"
   shows "b < c \<Longrightarrow> a << b >> c = (a >> (c - b)) AND (mask (size a - c))"
   apply(rule word_eqI)
   apply(auto simp:nth_shiftr nth_shiftl word_size word_ao_nth)
   done
 
 lemma shiftr_shiftl1:
   fixes a::"'a::len word"
   shows "c \<le> b \<Longrightarrow> a >> b << c = (a >> (b - c)) AND (NOT (mask c))"
   apply(rule word_eqI)
   apply(auto simp:nth_shiftr nth_shiftl word_size word_ops_nth_size)
   done
 
 lemma shiftr_shiftl2:
   fixes a::"'a::len word"
   shows "b < c \<Longrightarrow> a >> b << c = (a << (c - b)) AND (NOT (mask c))"
   apply(rule word_eqI)
   apply(auto simp:nth_shiftr nth_shiftl word_size word_ops_nth_size)
   done
 
 lemmas multi_shift_simps =
   shiftl_shiftl shiftr_shiftr
   shiftl_shiftr1 shiftl_shiftr2
   shiftr_shiftl1 shiftr_shiftl2
 
 lemma word_and_max_word:
   fixes a::"'a::len word"
   shows "x = max_word \<Longrightarrow> a AND x = a"
   by simp
 
 lemma word_and_full_mask_simp:
   \<open>x && Bit_Operations.mask LENGTH('a) = x\<close> for x :: \<open>'a::len word\<close>
 proof (rule bit_eqI)
   fix n
   assume \<open>2 ^ n \<noteq> (0 :: 'a word)\<close>
   then have \<open>n < LENGTH('a)\<close>
     by simp
   then show \<open>bit (x && Bit_Operations.mask LENGTH('a)) n \<longleftrightarrow> bit x n\<close>
     by (simp add: bit_and_iff bit_mask_iff)
 qed
 	
 lemma word8_and_max_simp:
   \<open>x && 0xFF = x\<close> for x :: \<open>8 word\<close>
   using word_and_full_mask_simp [of x]
   by (simp add: numeral_eq_Suc mask_Suc_exp)
 	
 lemma word16_and_max_simp:
   \<open>x && 0xFFFF = x\<close> for x :: \<open>16 word\<close>
   using word_and_full_mask_simp [of x]
   by (simp add: numeral_eq_Suc mask_Suc_exp)
 	
 lemma word32_and_max_simp:
   \<open>x && 0xFFFFFFFF = x\<close> for x :: \<open>32 word\<close>
   using word_and_full_mask_simp [of x]
   by (simp add: numeral_eq_Suc mask_Suc_exp)
 	
 lemma word64_and_max_simp:
   \<open>x && 0xFFFFFFFFFFFFFFFF = x\<close> for x :: \<open>64 word\<close>
   using word_and_full_mask_simp [of x]
   by (simp add: numeral_eq_Suc mask_Suc_exp)
 	
 lemmas word_and_max_simps =
   word8_and_max_simp
   word16_and_max_simp
   word32_and_max_simp
   word64_and_max_simp
 
 lemma word_and_1_bl:
   fixes x::"'a::len word"
   shows "(x AND 1) = of_bl [x !! 0]"
   by (simp add: mod_2_eq_odd test_bit_word_eq and_one_eq)
 
 lemma word_1_and_bl:
   fixes x::"'a::len word"
   shows "(1 AND x) = of_bl [x !! 0]"
   by (simp add: mod_2_eq_odd test_bit_word_eq one_and_eq)
 
 lemma scast_scast_id [simp]:
   "scast (scast x :: ('a::len) signed word) = (x :: 'a word)"
   "scast (scast y :: ('a::len) word) = (y :: 'a signed word)"
   by (auto simp: is_up scast_up_scast_id)
 
 lemma scast_ucast_id [simp]:
     "scast (ucast (x :: 'a::len word) :: 'a signed word) = x"
   by (metis down_cast_same is_down len_signed order_refl scast_scast_id(1))
 
 lemma ucast_scast_id [simp]:
     "ucast (scast (x :: 'a::len signed word) :: 'a word) = x"
   by (metis scast_scast_id(2) scast_ucast_id)
 
 lemma scast_of_nat [simp]:
     "scast (of_nat x :: 'a::len signed word) = (of_nat x :: 'a word)"
   by transfer simp
 
 lemma ucast_of_nat:
   "is_down (ucast :: 'a :: len word \<Rightarrow> 'b :: len word)
     \<Longrightarrow> ucast (of_nat n :: 'a word) = (of_nat n :: 'b word)"
   by transfer simp
 
 (* shortcut for some specific lengths *)
 lemma word_fixed_sint_1[simp]:
   "sint (1::8 word) = 1"
   "sint (1::16 word) = 1"
   "sint (1::32 word) = 1"
   "sint (1::64 word) = 1"
   by (auto simp: sint_word_ariths)
 
 lemma word_sint_1 [simp]:
   "sint (1::'a::len word) = (if LENGTH('a) = 1 then -1 else 1)"
   by (cases \<open>LENGTH('a)\<close>)
     (simp_all add: not_le sint_uint le_Suc_eq sbintrunc_minus_simps)
 
 lemma scast_1':
   "(scast (1::'a::len word) :: 'b::len word) =
    (word_of_int (sbintrunc (LENGTH('a::len) - Suc 0) (1::int)))"
   by transfer simp
 
 lemma scast_1:
   "(scast (1::'a::len word) :: 'b::len word) = (if LENGTH('a) = 1 then -1 else 1)"
   by (fact signed_1)
 
 lemma scast_eq_scast_id [simp]:
   "((scast (a :: 'a::len signed word) :: 'a word) = scast b) = (a = b)"
   by (metis ucast_scast_id)
 
 lemma ucast_eq_ucast_id [simp]:
   "((ucast (a :: 'a::len word) :: 'a signed word) = ucast b) = (a = b)"
   by (metis scast_ucast_id)
 
 lemma scast_ucast_norm [simp]:
   "(ucast (a :: 'a::len word) = (b :: 'a signed word)) = (a = scast b)"
   "((b :: 'a signed word) = ucast (a :: 'a::len word)) = (a = scast b)"
   by (metis scast_ucast_id ucast_scast_id)+
 
 lemma of_bl_drop:
   "of_bl (drop n xs) = (of_bl xs && mask (length xs - n))"
   apply (clarsimp simp: bang_eq test_bit_of_bl rev_nth cong: rev_conj_cong)
   apply (safe; simp add: word_size to_bl_nth)
   done
 
 lemma of_int_uint:
   "of_int (uint x) = x"
   by (fact word_of_int_uint)
 
 lemma shiftr_mask2:
   "n \<le> LENGTH('a) \<Longrightarrow> (mask n >> m :: ('a :: len) word) = mask (n - m)"
   apply (rule word_eqI)
   apply (simp add: nth_shiftr word_size)
   apply arith
   done
 
 corollary word_plus_and_or_coroll:
   "x && y = 0 \<Longrightarrow> x + y = x || y"
   using word_plus_and_or[where x=x and y=y]
   by simp
 
 corollary word_plus_and_or_coroll2:
   "(x && w) + (x && ~~ w) = x"
   apply (subst word_plus_and_or_coroll)
    apply (rule word_eqI, simp add: word_size word_ops_nth_size)
   apply (rule word_eqI, simp add: word_size word_ops_nth_size)
   apply blast
   done
 
 lemma less_le_mult_nat':
   "w * c < b * c ==> 0 \<le> c ==> Suc w * c \<le> b * (c::nat)"
   apply (rule mult_right_mono)
    apply (rule Suc_leI)
    apply (erule (1) mult_right_less_imp_less)
   apply assumption
   done
 
 lemmas less_le_mult_nat = less_le_mult_nat'[simplified distrib_right, simplified]
 
 (* FIXME: these should eventually be moved to HOL/Word. *)
 lemmas extra_sle_sless_unfolds [simp] =
     word_sle_eq[where a=0 and b=1]
     word_sle_eq[where a=0 and b="numeral n"]
     word_sle_eq[where a=1 and b=0]
     word_sle_eq[where a=1 and b="numeral n"]
     word_sle_eq[where a="numeral n" and b=0]
     word_sle_eq[where a="numeral n" and b=1]
     word_sless_alt[where a=0 and b=1]
     word_sless_alt[where a=0 and b="numeral n"]
     word_sless_alt[where a=1 and b=0]
     word_sless_alt[where a=1 and b="numeral n"]
     word_sless_alt[where a="numeral n" and b=0]
     word_sless_alt[where a="numeral n" and b=1]
   for n
 
 
 lemma to_bl_1:
   "to_bl (1::'a::len word) = replicate (LENGTH('a) - 1) False @ [True]"
   by (rule nth_equalityI) (auto simp add: to_bl_unfold nth_append rev_nth bit_1_iff not_less not_le)
 
 lemma list_of_false:
   "True \<notin> set xs \<Longrightarrow> xs = replicate (length xs) False"
   by (induct xs, simp_all)
 
 lemma eq_zero_set_bl:
   "(w = 0) = (True \<notin> set (to_bl w))"
   using list_of_false word_bl.Rep_inject by fastforce
 
 lemma diff_diff_less:
   "(i < m - (m - (n :: nat))) = (i < m \<and> i < n)"
   by auto
 
 lemma pop_count_0[simp]:
   "pop_count 0 = 0"
   by (clarsimp simp:pop_count_def)
 
 lemma pop_count_1[simp]:
   "pop_count 1 = 1"
   by (clarsimp simp:pop_count_def to_bl_1)
 
 lemma pop_count_0_imp_0:
   "(pop_count w = 0) = (w = 0)"
   apply (rule iffI)
    apply (clarsimp simp:pop_count_def)
    apply (subst (asm) filter_empty_conv)
    apply (clarsimp simp:eq_zero_set_bl)
    apply fast
   apply simp
   done
 
 end