diff --git a/thys/Saturation_Framework/Given_Clause_Architectures.thy b/thys/Saturation_Framework/Given_Clause_Architectures.thy
--- a/thys/Saturation_Framework/Given_Clause_Architectures.thy
+++ b/thys/Saturation_Framework/Given_Clause_Architectures.thy
@@ -1,1174 +1,1173 @@
 (*  Title:       Given Clause Prover Architectures
  *  Author:      Sophie Tourret <stourret at mpi-inf.mpg.de>, 2019-2020 *)
 
 section \<open>Given Clause Prover Architectures\<close>
 
 text \<open>This section covers all the results presented in the section 4 of the report.
   This is where abstract architectures of provers are defined and proven
   dynamically refutationally complete.\<close>
 
 theory Given_Clause_Architectures
   imports
     Lambda_Free_RPOs.Lambda_Free_Util
     Labeled_Lifting_to_Non_Ground_Calculi
 begin
 
 
 subsection \<open>Basis of the Given Clause Prover Architectures\<close>
 
 locale given_clause_basis = std?: labeled_lifting_intersection Bot_F Inf_F Bot_G Q
   entails_q Inf_G_q Red_I_q Red_F_q \<G>_F_q \<G>_I_q Inf_FL
   for
     Bot_F :: "'f set"
     and Inf_F :: "'f inference set"
     and Bot_G :: "'g set"
     and Q :: "'q set"
     and entails_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set \<Rightarrow> bool"
     and Inf_G_q :: \<open>'q \<Rightarrow> 'g inference set\<close>
     and Red_I_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g inference set"
     and Red_F_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set"
     and \<G>_F_q :: "'q \<Rightarrow> 'f \<Rightarrow> 'g set"
     and \<G>_I_q :: "'q \<Rightarrow> 'f inference \<Rightarrow> 'g inference set option"
     and Inf_FL :: \<open>('f \<times> 'l) inference set\<close>
   + fixes
     Equiv_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<doteq>" 50) and
     Prec_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<prec>\<cdot>" 50) and
     Prec_L :: "'l \<Rightarrow> 'l \<Rightarrow> bool" (infix "\<sqsubset>L" 50) and
     active :: "'l"
   assumes
     equiv_equiv_F: "equivp (\<doteq>)" and
     wf_prec_F: "minimal_element (\<prec>\<cdot>) UNIV" and
     wf_prec_L: "minimal_element (\<sqsubset>L) UNIV" and
     compat_equiv_prec: "C1 \<doteq> D1 \<Longrightarrow> C2 \<doteq> D2 \<Longrightarrow> C1 \<prec>\<cdot> C2 \<Longrightarrow> D1 \<prec>\<cdot> D2" and
     equiv_F_grounding: "q \<in> Q \<Longrightarrow> C1 \<doteq> C2 \<Longrightarrow> \<G>_F_q q C1 \<subseteq> \<G>_F_q q C2" and
     prec_F_grounding: "q \<in> Q \<Longrightarrow> C2 \<prec>\<cdot> C1 \<Longrightarrow> \<G>_F_q q C1 \<subseteq> \<G>_F_q q C2" and
     active_minimal: "l2 \<noteq> active \<Longrightarrow> active \<sqsubset>L l2" and
     at_least_two_labels: "\<exists>l2. active \<sqsubset>L l2" and
-    inf_never_active: "\<iota> \<in> Inf_FL \<Longrightarrow> snd (concl_of \<iota>) \<noteq> active" and
     static_ref_comp: "statically_complete_calculus Bot_F Inf_F (\<Turnstile>\<inter>\<G>)
       no_labels.Red_I_\<G> no_labels.Red_F_\<G>_empty"
 begin
 
 abbreviation Prec_eq_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<preceq>\<cdot>" 50) where
   "C \<preceq>\<cdot> D \<equiv> C \<doteq> D \<or> C \<prec>\<cdot> D"
 
 definition Prec_FL :: "('f \<times> 'l) \<Rightarrow> ('f \<times> 'l) \<Rightarrow> bool" (infix "\<sqsubset>" 50) where
   "Cl1 \<sqsubset> Cl2 \<longleftrightarrow> fst Cl1 \<prec>\<cdot> fst Cl2 \<or> (fst Cl1 \<doteq> fst Cl2 \<and> snd Cl1 \<sqsubset>L snd Cl2)"
 
 lemma irrefl_prec_F: "\<not> C \<prec>\<cdot> C"
   by (simp add: minimal_element.po[OF wf_prec_F, unfolded po_on_def irreflp_on_def])
 
 lemma trans_prec_F: "C1 \<prec>\<cdot> C2 \<Longrightarrow> C2 \<prec>\<cdot> C3 \<Longrightarrow> C1 \<prec>\<cdot> C3"
   by (auto intro: minimal_element.po[OF wf_prec_F, unfolded po_on_def transp_on_def, THEN conjunct2,
         simplified, rule_format])
 
 lemma wf_prec_FL: "minimal_element (\<sqsubset>) UNIV"
 proof
   show "po_on (\<sqsubset>) UNIV" unfolding po_on_def
   proof
     show "irreflp_on (\<sqsubset>) UNIV" unfolding irreflp_on_def Prec_FL_def
     proof
       fix Cl
       assume a_in: "Cl \<in> (UNIV::('f \<times> 'l) set)"
       have "\<not> (fst Cl \<prec>\<cdot> fst Cl)" using wf_prec_F minimal_element.min_elt_ex by force
       moreover have "\<not> (snd Cl \<sqsubset>L snd Cl)" using wf_prec_L minimal_element.min_elt_ex by force
       ultimately show "\<not> (fst Cl \<prec>\<cdot> fst Cl \<or> fst Cl \<doteq> fst Cl \<and> snd Cl \<sqsubset>L snd Cl)" by blast
     qed
   next
     show "transp_on (\<sqsubset>) UNIV" unfolding transp_on_def Prec_FL_def
     proof (simp, intro allI impI)
       fix C1 l1 C2 l2 C3 l3
       assume trans_hyp: "(C1 \<prec>\<cdot> C2 \<or> C1 \<doteq> C2 \<and> l1 \<sqsubset>L l2) \<and> (C2 \<prec>\<cdot> C3 \<or> C2 \<doteq> C3 \<and> l2 \<sqsubset>L l3)"
       have "C1 \<prec>\<cdot> C2 \<Longrightarrow> C2 \<doteq> C3 \<Longrightarrow> C1 \<prec>\<cdot> C3"
         using compat_equiv_prec by (metis equiv_equiv_F equivp_def)
       moreover have "C1 \<doteq> C2 \<Longrightarrow> C2 \<prec>\<cdot> C3 \<Longrightarrow> C1 \<prec>\<cdot> C3"
         using compat_equiv_prec by (metis equiv_equiv_F equivp_def)
       moreover have "l1 \<sqsubset>L l2 \<Longrightarrow> l2 \<sqsubset>L l3 \<Longrightarrow> l1 \<sqsubset>L l3"
         using wf_prec_L unfolding minimal_element_def po_on_def transp_on_def by (meson UNIV_I)
       moreover have "C1 \<doteq> C2 \<Longrightarrow> C2 \<doteq> C3 \<Longrightarrow> C1 \<doteq> C3"
         using equiv_equiv_F by (meson equivp_transp)
       ultimately show "C1 \<prec>\<cdot> C3 \<or> C1 \<doteq> C3 \<and> l1 \<sqsubset>L l3" using trans_hyp
         using trans_prec_F by blast
     qed
   qed
 next
   show "wfp_on (\<sqsubset>) UNIV" unfolding wfp_on_def
   proof
     assume contra: "\<exists>f. \<forall>i. f i \<in> UNIV \<and> f (Suc i) \<sqsubset> f i"
     then obtain f where
       f_suc: "\<forall>i. f (Suc i) \<sqsubset> f i"
       by blast
 
     define R :: "(('f \<times> 'l) \<times> ('f \<times> 'l)) set" where
       "R = {(Cl1, Cl2). fst Cl1 \<prec>\<cdot> fst Cl2}"
     define S :: "(('f \<times> 'l) \<times> ('f \<times> 'l)) set" where
       "S = {(Cl1, Cl2). fst Cl1 \<doteq> fst Cl2 \<and> snd Cl1 \<sqsubset>L snd Cl2}"
 
     obtain k where
       f_chain: "\<forall>i. (f (Suc (i + k)), f (i + k)) \<in> S"
     proof (atomize_elim, rule wf_infinite_down_chain_compatible[of R f S])
       show "wf R"
         unfolding R_def using wf_app[OF wf_prec_F[unfolded minimal_element_def, THEN conjunct2,
               unfolded wfp_on_UNIV wfP_def]]
         by force
     next
       show "\<forall>i. (f (Suc i), f i) \<in> R \<union> S"
         using f_suc unfolding R_def S_def Prec_FL_def by blast
     next
       show "R O S \<subseteq> R"
         unfolding R_def S_def using compat_equiv_prec equiv_equiv_F equivp_reflp by fastforce
     qed
 
     define g where
       "\<And>i. g i = f (i + k)"
 
     have g_chain: "\<forall>i. (g (Suc i), g i) \<in> S"
       unfolding g_def using f_chain by simp
     have wf_s: "wf S"
       unfolding S_def
       by (rule wf_subset[OF wf_app[OF wf_prec_L[unfolded minimal_element_def, THEN conjunct2,
                 unfolded wfp_on_UNIV wfP_def], of snd]])
         fast
     show False
       using g_chain[unfolded S_def]
         wf_s[unfolded S_def, folded wfP_def wfp_on_UNIV, unfolded wfp_on_def]
       by auto
   qed
 qed
 
 definition active_subset :: "('f \<times> 'l) set \<Rightarrow> ('f \<times> 'l) set" where
   "active_subset M = {CL \<in> M. snd CL = active}"
 
 definition passive_subset :: "('f \<times> 'l) set \<Rightarrow> ('f \<times> 'l) set" where
   "passive_subset M = {CL \<in> M. snd CL \<noteq> active}"
 
 lemma active_subset_insert[simp]:
   "active_subset (insert Cl N) = (if snd Cl = active then {Cl} else {}) \<union> active_subset N"
   unfolding active_subset_def by auto
 
 lemma active_subset_union[simp]: "active_subset (M \<union> N) = active_subset M \<union> active_subset N"
   unfolding active_subset_def by auto
 
 lemma passive_subset_insert[simp]:
   "passive_subset (insert Cl N) = (if snd Cl \<noteq> active then {Cl} else {}) \<union> passive_subset N"
   unfolding passive_subset_def by auto
 
 lemma passive_subset_union[simp]: "passive_subset (M \<union> N) = passive_subset M \<union> passive_subset N"
   unfolding passive_subset_def by auto
 
 sublocale std?: statically_complete_calculus Bot_FL Inf_FL "(\<Turnstile>\<inter>\<G>L)" Red_I Red_F
   using labeled_static_ref[OF static_ref_comp] .
 
 lemma labeled_tiebreaker_lifting:
   assumes q_in: "q \<in> Q"
   shows "tiebreaker_lifting Bot_FL Inf_FL Bot_G (entails_q q) (Inf_G_q q)
     (Red_I_q q) (Red_F_q q) (\<G>_F_L_q q) (\<G>_I_L_q q) (\<lambda>g. Prec_FL)"
 proof -
   have "tiebreaker_lifting Bot_FL Inf_FL Bot_G (entails_q q) (Inf_G_q q)
     (Red_I_q q) (Red_F_q q) (\<G>_F_L_q q) (\<G>_I_L_q q) (\<lambda>g Cl Cl'. False)"
     using ord_fam_lifted_q[OF q_in] .
   then have "standard_lifting Inf_FL Bot_G (Inf_G_q q) (entails_q q) (Red_I_q q)
     (Red_F_q q) Bot_FL (\<G>_F_L_q q) (\<G>_I_L_q q)"
     using lifted_q[OF q_in] by blast
   then show "tiebreaker_lifting Bot_FL Inf_FL Bot_G (entails_q q) (Inf_G_q q)
     (Red_I_q q) (Red_F_q q) (\<G>_F_L_q q) (\<G>_I_L_q q) (\<lambda>g. Prec_FL)"
     using wf_prec_FL by (simp add: tiebreaker_lifting.intro tiebreaker_lifting_axioms.intro)
 qed
 
 sublocale lifting_intersection Inf_FL Bot_G Q Inf_G_q entails_q Red_I_q Red_F_q
   Bot_FL \<G>_F_L_q \<G>_I_L_q "\<lambda>g. Prec_FL"
   using labeled_tiebreaker_lifting unfolding lifting_intersection_def
   by (simp add: lifting_intersection_axioms.intro
       no_labels.ground.consequence_relation_family_axioms
       no_labels.ground.inference_system_family_axioms)
 
 notation derive (infix "\<rhd>L" 50)
 
 lemma std_Red_I_eq: "std.Red_I = Red_I_\<G>"
   unfolding Red_I_\<G>_q_def Red_I_\<G>_L_q_def by simp
 
 lemma std_Red_F_eq: "std.Red_F = Red_F_\<G>_empty"
   unfolding Red_F_\<G>_empty_q_def Red_F_\<G>_empty_L_q_def by simp
 
 sublocale statically_complete_calculus Bot_FL Inf_FL "(\<Turnstile>\<inter>\<G>L)" Red_I Red_F
   by unfold_locales (use statically_complete std_Red_I_eq in auto)
 
 (* lem:redundant-labeled-inferences *)
 lemma labeled_red_inf_eq_red_inf:
   assumes i_in: "\<iota> \<in> Inf_FL"
   shows "\<iota> \<in> Red_I N \<longleftrightarrow> to_F \<iota> \<in> no_labels.Red_I_\<G> (fst ` N)"
 proof
   assume i_in2: "\<iota> \<in> Red_I N"
   then have "X \<in> Red_I_\<G>_q ` Q \<Longrightarrow> \<iota> \<in> X N" for X
     unfolding Red_I_def by blast
   obtain X0 where "X0 \<in> Red_I_\<G>_q ` Q"
     using Q_nonempty by blast
   then obtain q0 where x0_is: "X0 N = Red_I_\<G>_q q0 N" by blast
   then obtain Y0 where y0_is: "Y0 (fst ` N) = to_F ` (X0 N)" by auto
   have "Y0 (fst ` N) = no_labels.Red_I_\<G>_q q0 (fst ` N)"
     unfolding  y0_is
   proof
     show "to_F ` X0 N \<subseteq> no_labels.Red_I_\<G>_q q0 (fst ` N)"
     proof
       fix \<iota>0
       assume i0_in: "\<iota>0 \<in> to_F ` X0 N"
       then have i0_in2: "\<iota>0 \<in> to_F ` Red_I_\<G>_q q0 N"
         using x0_is by argo
       then obtain \<iota>0_FL where i0_FL_in: "\<iota>0_FL \<in> Inf_FL" and i0_to_i0_FL: "\<iota>0 = to_F \<iota>0_FL" and
         subs1: "((\<G>_I_L_q q0 \<iota>0_FL) \<noteq> None \<and>
             the (\<G>_I_L_q q0 \<iota>0_FL) \<subseteq> Red_I_q q0 (\<G>_Fset_q q0 N))
             \<or> ((\<G>_I_L_q q0 \<iota>0_FL = None) \<and>
             \<G>_F_L_q q0 (concl_of \<iota>0_FL) \<subseteq> \<G>_Fset_q q0 N \<union> Red_F_q q0 (\<G>_Fset_q q0 N))"
         unfolding Red_I_\<G>_q_def by blast
       have concl_swap: "fst (concl_of \<iota>0_FL) = concl_of \<iota>0"
         unfolding concl_of_def i0_to_i0_FL to_F_def by simp
       have i0_in3: "\<iota>0 \<in> Inf_F"
         using i0_to_i0_FL Inf_FL_to_Inf_F[OF i0_FL_in] unfolding to_F_def by blast
       {
         assume
           not_none: "\<G>_I_q q0 \<iota>0 \<noteq> None" and
           "the (\<G>_I_q q0 \<iota>0) \<noteq> {}"
         then obtain \<iota>1 where i1_in: "\<iota>1 \<in> the (\<G>_I_q q0 \<iota>0)" by blast
         have "the (\<G>_I_q q0 \<iota>0) \<subseteq> Red_I_q q0 (no_labels.\<G>_Fset_q q0 (fst ` N))"
           using subs1 i0_to_i0_FL not_none by auto
       }
       moreover {
         assume
           is_none: "\<G>_I_q q0 \<iota>0 = None"
         then have "\<G>_F_q q0 (concl_of \<iota>0) \<subseteq> no_labels.\<G>_Fset_q q0 (fst ` N)
             \<union> Red_F_q q0 (no_labels.\<G>_Fset_q q0 (fst ` N))"
           using subs1 i0_to_i0_FL concl_swap by simp
       }
       ultimately show "\<iota>0 \<in> no_labels.Red_I_\<G>_q q0 (fst ` N)"
         unfolding no_labels.Red_I_\<G>_q_def using i0_in3 by auto
     qed
   next
     show "no_labels.Red_I_\<G>_q q0 (fst ` N) \<subseteq> to_F ` X0 N"
     proof
       fix \<iota>0
       assume i0_in: "\<iota>0 \<in> no_labels.Red_I_\<G>_q q0 (fst ` N)"
       then have i0_in2: "\<iota>0 \<in> Inf_F"
         unfolding no_labels.Red_I_\<G>_q_def by blast
       obtain \<iota>0_FL where i0_FL_in: "\<iota>0_FL \<in> Inf_FL" and i0_to_i0_FL: "\<iota>0 = to_F \<iota>0_FL"
         using Inf_F_to_Inf_FL[OF i0_in2] unfolding to_F_def
         by (metis Ex_list_of_length fst_conv inference.exhaust_sel inference.inject map_fst_zip)
       have concl_swap: "fst (concl_of \<iota>0_FL) = concl_of \<iota>0"
         unfolding concl_of_def i0_to_i0_FL to_F_def by simp
       have subs1: "((\<G>_I_L_q q0 \<iota>0_FL) \<noteq> None \<and>
            the (\<G>_I_L_q q0 \<iota>0_FL) \<subseteq> Red_I_q q0 (\<G>_Fset_q q0 N))
            \<or> ((\<G>_I_L_q q0 \<iota>0_FL = None) \<and>
            \<G>_F_L_q q0 (concl_of \<iota>0_FL) \<subseteq> (\<G>_Fset_q q0 N \<union> Red_F_q q0 (\<G>_Fset_q q0 N)))"
         using i0_in i0_to_i0_FL concl_swap unfolding no_labels.Red_I_\<G>_q_def by simp
       then have "\<iota>0_FL \<in> Red_I_\<G>_q q0 N"
         using i0_FL_in unfolding Red_I_\<G>_q_def by simp
       then show "\<iota>0 \<in> to_F ` X0 N"
         using x0_is i0_to_i0_FL i0_in2 by blast
     qed
   qed
   then have "Y \<in> no_labels.Red_I_\<G>_q ` Q \<Longrightarrow> to_F \<iota> \<in> Y (fst ` N)" for Y
     using i_in2 no_labels.Red_I_def std_Red_I_eq red_inf_impl by force
   then show "to_F \<iota> \<in> no_labels.Red_I_\<G> (fst ` N)"
     unfolding Red_I_def no_labels.Red_I_\<G>_def by blast
 next
   assume to_F_in: "to_F \<iota> \<in> no_labels.Red_I_\<G> (fst ` N)"
   have imp_to_F: "X \<in> no_labels.Red_I_\<G>_q ` Q \<Longrightarrow> to_F \<iota> \<in> X (fst ` N)" for X
     using to_F_in unfolding no_labels.Red_I_\<G>_def by blast
   then have to_F_in2: "to_F \<iota> \<in> no_labels.Red_I_\<G>_q q (fst ` N)" if "q \<in> Q" for q
     using that by auto
   have "Red_I_\<G>_q q N = {\<iota>0_FL \<in> Inf_FL. to_F \<iota>0_FL \<in> no_labels.Red_I_\<G>_q q (fst ` N)}" for q
   proof
     show "Red_I_\<G>_q q N \<subseteq> {\<iota>0_FL \<in> Inf_FL. to_F \<iota>0_FL \<in> no_labels.Red_I_\<G>_q q (fst ` N)}"
     proof
       fix q0 \<iota>1
       assume
         i1_in: "\<iota>1 \<in> Red_I_\<G>_q q0 N"
       have i1_in2: "\<iota>1 \<in> Inf_FL"
         using i1_in unfolding Red_I_\<G>_q_def by blast
       then have to_F_i1_in: "to_F \<iota>1 \<in> Inf_F"
         using Inf_FL_to_Inf_F unfolding to_F_def by simp
       have concl_swap: "fst (concl_of \<iota>1) = concl_of (to_F \<iota>1)"
         unfolding concl_of_def to_F_def by simp
       then have i1_to_F_in: "to_F \<iota>1 \<in> no_labels.Red_I_\<G>_q q0 (fst ` N)"
         using i1_in to_F_i1_in unfolding Red_I_\<G>_q_def no_labels.Red_I_\<G>_q_def by force
       show "\<iota>1 \<in> {\<iota>0_FL \<in> Inf_FL. to_F \<iota>0_FL \<in> no_labels.Red_I_\<G>_q q0 (fst ` N)}"
         using i1_in2 i1_to_F_in by blast
     qed
   next
     show "{\<iota>0_FL \<in> Inf_FL. to_F \<iota>0_FL \<in> no_labels.Red_I_\<G>_q q (fst ` N)} \<subseteq> Red_I_\<G>_q q N"
     proof
       fix q0 \<iota>1
       assume
         i1_in: "\<iota>1 \<in> {\<iota>0_FL \<in> Inf_FL. to_F \<iota>0_FL \<in> no_labels.Red_I_\<G>_q q0 (fst ` N)}"
       then have i1_in2: "\<iota>1 \<in> Inf_FL" by blast
       then have to_F_i1_in: "to_F \<iota>1 \<in> Inf_F"
         using Inf_FL_to_Inf_F unfolding to_F_def by simp
       have concl_swap: "fst (concl_of \<iota>1) = concl_of (to_F \<iota>1)"
         unfolding concl_of_def to_F_def by simp
       then have "((\<G>_I_L_q q0 \<iota>1) \<noteq> None \<and> the (\<G>_I_L_q q0 \<iota>1) \<subseteq> Red_I_q q0 (\<G>_Fset_q q0 N))
         \<or> (\<G>_I_L_q q0 \<iota>1 = None \<and>
           \<G>_F_L_q q0 (concl_of \<iota>1) \<subseteq> \<G>_Fset_q q0 N \<union> Red_F_q q0 (\<G>_Fset_q q0 N))"
         using i1_in unfolding no_labels.Red_I_\<G>_q_def by auto
       then show "\<iota>1 \<in> Red_I_\<G>_q q0 N"
         using i1_in2 unfolding Red_I_\<G>_q_def by blast
     qed
   qed
   then have "\<iota> \<in> Red_I_\<G>_q q N" if "q \<in> Q" for q
     using that to_F_in2 i_in unfolding Red_I_\<G>_q_def no_labels.Red_I_\<G>_q_def by auto
   then show "\<iota> \<in> Red_I_\<G> N"
     unfolding Red_I_\<G>_def by blast
 qed
 
 (* lem:redundant-labeled-formulas *)
 lemma red_labeled_clauses:
   assumes \<open>C \<in> no_labels.Red_F_\<G>_empty (fst ` N) \<or>
     (\<exists>C' \<in> fst ` N. C' \<prec>\<cdot> C) \<or> (\<exists>(C', L') \<in> N. L' \<sqsubset>L L \<and> C' \<preceq>\<cdot> C)\<close>
   shows \<open>(C, L) \<in> Red_F N\<close>
 proof -
   note assms
   moreover have i: \<open>C \<in> no_labels.Red_F_\<G>_empty (fst ` N) \<Longrightarrow> (C, L) \<in> Red_F N\<close>
   proof -
     assume "C \<in> no_labels.Red_F_\<G>_empty (fst ` N)"
     then have "C \<in> no_labels.Red_F_\<G>_empty_q q (fst ` N)" if "q \<in> Q" for q
       unfolding no_labels.Red_F_\<G>_empty_def using that by fast
     then have g_in_red: "\<G>_F_q q C \<subseteq> Red_F_q q (no_labels.\<G>_Fset_q q (fst ` N))" if "q \<in> Q" for q
       unfolding no_labels.Red_F_\<G>_empty_q_def using that by blast
     have "\<G>_F_L_q q (C, L) \<subseteq> Red_F_q q (\<G>_Fset_q q N)" if "q \<in> Q" for q
       using that g_in_red by simp
     then show ?thesis
       unfolding Red_F_def Red_F_\<G>_q_def by blast
   qed
   moreover have ii: \<open>\<exists>C' \<in> fst ` N. C' \<prec>\<cdot> C \<Longrightarrow> (C, L) \<in> Red_F N\<close>
   proof -
     assume "\<exists>C' \<in> fst ` N. C' \<prec>\<cdot> C"
     then obtain C' where c'_in: "C' \<in> fst ` N" and c_prec_c': "C' \<prec>\<cdot> C" by blast
     obtain L' where c'_l'_in: "(C', L') \<in> N" using c'_in by auto
     have c'_l'_prec: "(C', L') \<sqsubset> (C, L)"
       using c_prec_c' unfolding Prec_FL_def by simp
     have c_in_c'_g: "\<G>_F_q q C \<subseteq> \<G>_F_q q C'" if "q \<in> Q" for q
       using prec_F_grounding[OF that c_prec_c'] by presburger
     then have "\<G>_F_L_q q (C, L) \<subseteq> \<G>_F_L_q q (C', L')" if "q \<in> Q" for q
       using that by auto
     then have "(C, L) \<in> Red_F_\<G>_q q N" if "q \<in> Q" for q
       unfolding Red_F_\<G>_q_def using that c'_l'_in c'_l'_prec by blast
     then show ?thesis
       unfolding Red_F_def by blast
   qed
   moreover have iii: \<open>\<exists>(C', L') \<in> N. L' \<sqsubset>L L \<and> C' \<preceq>\<cdot> C \<Longrightarrow> (C, L) \<in> Red_F N\<close>
   proof -
     assume "\<exists>(C', L') \<in> N. L' \<sqsubset>L L \<and> C' \<preceq>\<cdot> C"
     then obtain C' L' where c'_l'_in: "(C', L') \<in> N" and l'_sub_l: "L' \<sqsubset>L L" and c'_sub_c: "C' \<preceq>\<cdot> C"
       by fast
     have "(C, L) \<in> Red_F N" if "C' \<prec>\<cdot> C"
       using that c'_l'_in ii by fastforce
     moreover {
       assume equiv_c_c': "C \<doteq> C'"
       then have equiv_c'_c: "C' \<doteq> C"
         using equiv_equiv_F by (simp add: equivp_symp)
       then have c'_l'_prec: "(C', L') \<sqsubset> (C, L)"
         using l'_sub_l unfolding Prec_FL_def by simp
       have "\<G>_F_q q C = \<G>_F_q q C'" if "q \<in> Q" for q
         using that equiv_F_grounding equiv_c_c' equiv_c'_c by (simp add: set_eq_subset)
       then have "\<G>_F_L_q q (C, L) = \<G>_F_L_q q (C', L')" if "q \<in> Q" for q
         using that by auto
       then have "(C, L) \<in> Red_F_\<G>_q q N" if "q \<in> Q" for q
         unfolding Red_F_\<G>_q_def using that c'_l'_in c'_l'_prec by blast
       then have ?thesis
         unfolding Red_F_def by blast
     }
     ultimately show ?thesis
       using c'_sub_c equiv_equiv_F equivp_symp by fastforce
   qed
   ultimately show ?thesis
     by blast
 qed
 
 end
   
   
 subsection \<open>Given Clause Procedure\<close>
 
 locale given_clause = given_clause_basis Bot_F Inf_F Bot_G Q entails_q Inf_G_q Red_I_q
   Red_F_q \<G>_F_q \<G>_I_q Inf_FL Equiv_F Prec_F Prec_L active
   for
     Bot_F :: "'f set" and
     Inf_F :: "'f inference set" and
     Bot_G :: "'g set" and
     Q :: "'q set" and
     entails_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set \<Rightarrow> bool" and
     Inf_G_q :: \<open>'q \<Rightarrow> 'g inference set\<close> and
     Red_I_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g inference set" and
     Red_F_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set" and
     \<G>_F_q :: "'q \<Rightarrow> 'f \<Rightarrow> 'g set"  and
     \<G>_I_q :: "'q \<Rightarrow> 'f inference \<Rightarrow> 'g inference set option" and
     Inf_FL :: \<open>('f \<times> 'l) inference set\<close> and
     Equiv_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<doteq>" 50) and
     Prec_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<prec>\<cdot>" 50) and
     Prec_L :: "'l \<Rightarrow> 'l \<Rightarrow> bool" (infix "\<sqsubset>L" 50) and
     active :: 'l +
   assumes
     inf_have_prems: "\<iota>F \<in> Inf_F \<Longrightarrow> prems_of \<iota>F \<noteq> []"
 begin
   
 lemma labeled_inf_have_prems: "\<iota> \<in> Inf_FL \<Longrightarrow> prems_of \<iota> \<noteq> []"
   using inf_have_prems Inf_FL_to_Inf_F by fastforce
 
 inductive step :: "('f \<times> 'l) set \<Rightarrow> ('f \<times> 'l) set \<Rightarrow> bool" (infix "\<leadsto>GC" 50) where
   process: "N1 = N \<union> M \<Longrightarrow> N2 = N \<union> M' \<Longrightarrow> M \<subseteq> Red_F (N \<union> M') \<Longrightarrow>
     active_subset M' = {} \<Longrightarrow> N1 \<leadsto>GC N2"
 | infer: "N1 = N \<union> {(C, L)} \<Longrightarrow> N2 = N \<union> {(C, active)} \<union> M \<Longrightarrow> L \<noteq> active \<Longrightarrow>
     active_subset M = {} \<Longrightarrow>
-    no_labels.Inf_between (fst ` (active_subset N)) {C}
+    no_labels.Inf_between (fst ` active_subset N) {C}
     \<subseteq> no_labels.Red_I (fst ` (N \<union> {(C, active)} \<union> M)) \<Longrightarrow>
     N1 \<leadsto>GC N2"
   
 lemma one_step_equiv: "N1 \<leadsto>GC N2 \<Longrightarrow> N1 \<rhd>L N2"
 proof (cases N1 N2 rule: step.cases)
   show "N1 \<leadsto>GC N2 \<Longrightarrow> N1 \<leadsto>GC N2" by blast
 next
   fix N M M'
   assume
     gc_step: "N1 \<leadsto>GC N2" and
     n1_is: "N1 = N \<union> M" and
     n2_is: "N2 = N \<union> M'" and
     m_red: "M \<subseteq> Red_F (N \<union> M')" and
     active_empty: "active_subset M' = {}"
   have "N1 - N2 \<subseteq> Red_F N2"
     using n1_is n2_is m_red by auto
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 next
   fix N C L M
   assume
     gc_step: "N1 \<leadsto>GC N2" and
     n1_is: "N1 = N \<union> {(C, L)}" and
     not_active: "L \<noteq> active" and
     n2_is: "N2 = N \<union> {(C, active)} \<union> M" and
     active_empty: "active_subset M = {}"
   have "(C, active) \<in> N2" using n2_is by auto
   moreover have "C \<preceq>\<cdot> C" using equiv_equiv_F by (metis equivp_def)
   moreover have "active \<sqsubset>L L" using active_minimal[OF not_active] .
   ultimately have "{(C, L)} \<subseteq> Red_F N2"
     using red_labeled_clauses by blast
   moreover have "N1 - N2 = {} \<or> N1 - N2 = {(C, L)}" using n1_is n2_is by blast
   ultimately have "N1 - N2 \<subseteq> Red_F N2"
     using std_Red_F_eq by blast
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 qed
 
 (* lem:gc-derivations-are-red-derivations *)
 lemma gc_to_red: "chain (\<leadsto>GC) Ns \<Longrightarrow> chain (\<rhd>L) Ns"
   using one_step_equiv Lazy_List_Chain.chain_mono by blast
 
 lemma (in-) all_ex_finite_set: "(\<forall>(j::nat)\<in>{0..<m}. \<exists>(n::nat). P j n) \<Longrightarrow>
   (\<forall>n1 n2. \<forall>j\<in>{0..<m}. P j n1 \<longrightarrow> P j n2 \<longrightarrow> n1 = n2) \<Longrightarrow> finite {n. \<exists>j \<in> {0..<m}. P j n}" for m P
 proof -
   fix m::nat and P:: "nat \<Rightarrow> nat \<Rightarrow> bool"
   assume
     allj_exn: "\<forall>j\<in>{0..<m}. \<exists>n. P j n" and
     uniq_n: "\<forall>n1 n2. \<forall>j\<in>{0..<m}. P j n1 \<longrightarrow> P j n2 \<longrightarrow> n1 = n2"
   have "{n. \<exists>j \<in> {0..<m}. P j n} = (\<Union>((\<lambda>j. {n. P j n}) ` {0..<m}))" by blast
   then have imp_finite: "(\<forall>j\<in>{0..<m}. finite {n. P j n}) \<Longrightarrow> finite {n. \<exists>j \<in> {0..<m}. P j n}"
     using finite_UN[of "{0..<m}" "\<lambda>j. {n. P j n}"] by simp
   have "\<forall>j\<in>{0..<m}. \<exists>!n. P j n" using allj_exn uniq_n by blast
   then have "\<forall>j\<in>{0..<m}. finite {n. P j n}" by (metis bounded_nat_set_is_finite lessI mem_Collect_eq)
   then show "finite {n. \<exists>j \<in> {0..<m}. P j n}" using imp_finite by simp
 qed
 
 (* lem:fair-gc-derivations *)
 lemma gc_fair:
   assumes
     deriv: "chain (\<leadsto>GC) Ns" and
     init_state: "active_subset (lhd Ns) = {}" and
     final_state: "passive_subset (Liminf_llist Ns) = {}"
   shows "fair Ns"
   unfolding fair_def
 proof
   fix \<iota>
   assume i_in: "\<iota> \<in> Inf_from (Liminf_llist Ns)"
   note lhd_is = lhd_conv_lnth[OF chain_not_lnull[OF deriv]]
   have i_in_inf_fl: "\<iota> \<in> Inf_FL" using i_in unfolding Inf_from_def by blast
   have "Liminf_llist Ns = active_subset (Liminf_llist Ns)"
     using final_state unfolding passive_subset_def active_subset_def by blast
   then have i_in2: "\<iota> \<in> Inf_from (active_subset (Liminf_llist Ns))" using i_in by simp
   define m where "m = length (prems_of \<iota>)"
   then have m_def_F: "m = length (prems_of (to_F \<iota>))" unfolding to_F_def by simp
   have i_in_F: "to_F \<iota> \<in> Inf_F"
     using i_in Inf_FL_to_Inf_F unfolding Inf_from_def to_F_def by blast
   then have m_pos: "m > 0" using m_def_F using inf_have_prems by blast
   have exist_nj: "\<forall>j \<in> {0..<m}. (\<exists>nj. enat (Suc nj) < llength Ns \<and>
       prems_of \<iota> ! j \<notin> active_subset (lnth Ns nj) \<and>
       (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (lnth Ns k)))"
   proof clarify
     fix j
     assume j_in: "j \<in> {0..<m}"
     then obtain C where c_is: "(C, active) = prems_of \<iota> ! j"
       using i_in2 unfolding m_def Inf_from_def active_subset_def
       by (smt Collect_mem_eq Collect_mono_iff atLeastLessThan_iff nth_mem old.prod.exhaust snd_conv)
     then have "(C, active) \<in> Liminf_llist Ns"
       using j_in i_in unfolding m_def Inf_from_def by force
     then obtain nj where nj_is: "enat nj < llength Ns" and
       c_in2: "(C, active) \<in> \<Inter> (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns})"
       unfolding Liminf_llist_def using init_state by blast
     then have c_in3: "\<forall>k. k \<ge> nj \<longrightarrow> enat k < llength Ns \<longrightarrow> (C, active) \<in> lnth Ns k" by blast
     have nj_pos: "nj > 0" using init_state c_in2 nj_is
       unfolding active_subset_def lhd_is by force
     obtain nj_min where nj_min_is: "nj_min = (LEAST nj. enat nj < llength Ns \<and>
         (C, active) \<in> \<Inter> (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns}))" by blast
     then have in_allk: "\<forall>k. k \<ge> nj_min \<longrightarrow> enat k < llength Ns \<longrightarrow> (C, active) \<in> (lnth Ns k)"
       using c_in3 nj_is c_in2
       by (metis (mono_tags, lifting) INT_E LeastI_ex mem_Collect_eq)
     have njm_smaller_D: "enat nj_min < llength Ns"
       using nj_min_is
       by (smt LeastI_ex \<open>\<And>thesis. (\<And>nj. \<lbrakk>enat nj < llength Ns;
           (C, active) \<in> \<Inter> (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns})\<rbrakk> \<Longrightarrow> thesis) \<Longrightarrow> thesis\<close>)
     have "nj_min > 0"
       using nj_is c_in2 nj_pos nj_min_is lhd_is
       by (metis (mono_tags, lifting) Collect_empty_eq \<open>(C, active) \<in> Liminf_llist Ns\<close>
           \<open>Liminf_llist Ns = active_subset (Liminf_llist Ns)\<close>
           \<open>\<forall>k\<ge>nj_min. enat k < llength Ns \<longrightarrow> (C, active) \<in> lnth Ns k\<close> active_subset_def init_state
           linorder_not_less mem_Collect_eq zero_enat_def chain_length_pos[OF deriv])
     then obtain njm_prec where nj_prec_is: "Suc njm_prec = nj_min" using gr0_conv_Suc by auto
     then have njm_prec_njm: "njm_prec < nj_min" by blast
     then have njm_prec_njm_enat: "enat njm_prec < enat nj_min" by simp
     have njm_prec_smaller_d: "njm_prec < llength Ns"
       by (rule less_trans[OF njm_prec_njm_enat njm_smaller_D])
     have njm_prec_all_suc: "\<forall>k>njm_prec. enat k < llength Ns \<longrightarrow> (C, active) \<in> lnth Ns k"
       using nj_prec_is in_allk by simp
     have notin_njm_prec: "(C, active) \<notin> lnth Ns njm_prec"
     proof (rule ccontr)
       assume "\<not> (C, active) \<notin> lnth Ns njm_prec"
       then have absurd_hyp: "(C, active) \<in> lnth Ns njm_prec" by simp
       have prec_smaller: "enat njm_prec < llength Ns" using nj_min_is nj_prec_is
         by (smt LeastI_ex Suc_leD \<open>\<And>thesis. (\<And>nj. \<lbrakk>enat nj < llength Ns;
             (C, active) \<in> \<Inter> (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns})\<rbrakk> \<Longrightarrow> thesis) \<Longrightarrow> thesis\<close>
             enat_ord_simps(1) le_eq_less_or_eq le_less_trans)
       have "(C, active) \<in> \<Inter> (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns})"
       proof -
         {
           fix k
           assume k_in: "njm_prec \<le> k \<and> enat k < llength Ns"
           have "k = njm_prec \<Longrightarrow> (C, active) \<in> lnth Ns k" using absurd_hyp by simp
           moreover have "njm_prec < k \<Longrightarrow> (C, active) \<in> lnth Ns k"
             using nj_prec_is in_allk k_in by simp
           ultimately have "(C, active) \<in> lnth Ns k" using k_in by fastforce
         }
         then show "(C, active) \<in> \<Inter> (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns})" by blast
       qed
       then have "enat njm_prec < llength Ns \<and>
           (C, active) \<in> \<Inter> (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns})"
         using prec_smaller by blast
       then show False
         using nj_min_is nj_prec_is Orderings.wellorder_class.not_less_Least njm_prec_njm by blast
     qed
     then have notin_active_subs_njm_prec: "(C, active) \<notin> active_subset (lnth Ns njm_prec)"
       unfolding active_subset_def by blast
     then show "\<exists>nj. enat (Suc nj) < llength Ns \<and> prems_of \<iota> ! j \<notin> active_subset (lnth Ns nj) \<and>
         (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (lnth Ns k))"
       using c_is njm_prec_all_suc njm_prec_smaller_d by (metis (mono_tags, lifting)
           active_subset_def mem_Collect_eq nj_prec_is njm_smaller_D snd_conv)
   qed
   define nj_set where "nj_set = {nj. (\<exists>j\<in>{0..<m}. enat (Suc nj) < llength Ns \<and>
       prems_of \<iota> ! j \<notin> active_subset (lnth Ns nj) \<and>
       (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (lnth Ns k)))}"
   then have nj_not_empty: "nj_set \<noteq> {}"
   proof -
     have zero_in: "0 \<in> {0..<m}" using m_pos by simp
     then obtain n0 where "enat (Suc n0) < llength Ns" and
       "prems_of \<iota> ! 0 \<notin> active_subset (lnth Ns n0)" and
       "\<forall>k>n0. enat k < llength Ns \<longrightarrow> prems_of \<iota> ! 0 \<in> active_subset (lnth Ns k)"
       using exist_nj by fast
     then have "n0 \<in> nj_set" unfolding nj_set_def using zero_in by blast
     then show "nj_set \<noteq> {}" by auto
   qed
   have nj_finite: "finite nj_set"
     using all_ex_finite_set[OF exist_nj]
     by (metis (no_types, lifting) Suc_ile_eq dual_order.strict_implies_order
         linorder_neqE_nat nj_set_def)
       (* the n below in the n-1 from the pen-and-paper proof *)
   have "\<exists>n \<in> nj_set. \<forall>nj \<in> nj_set. nj \<le> n"
     using nj_not_empty nj_finite using Max_ge Max_in by blast
   then obtain n where n_in: "n \<in> nj_set" and n_bigger: "\<forall>nj \<in> nj_set. nj \<le> n" by blast
   then obtain j0 where j0_in: "j0 \<in> {0..<m}" and suc_n_length: "enat (Suc n) < llength Ns" and
     j0_notin: "prems_of \<iota> ! j0 \<notin> active_subset (lnth Ns n)" and
     j0_allin: "(\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j0 \<in> active_subset (lnth Ns k))"
     unfolding nj_set_def by blast
   obtain C0 where C0_is: "prems_of \<iota> ! j0 = (C0, active)" using j0_in
     using i_in2 unfolding m_def Inf_from_def active_subset_def
     by (smt Collect_mem_eq Collect_mono_iff atLeastLessThan_iff nth_mem old.prod.exhaust snd_conv)
   then have C0_prems_i: "(C0, active) \<in> set (prems_of \<iota>)" using in_set_conv_nth j0_in m_def by force
   have C0_in: "(C0, active) \<in> (lnth Ns (Suc n))"
     using C0_is j0_allin suc_n_length by (simp add: active_subset_def)
   have C0_notin: "(C0, active) \<notin> (lnth Ns n)" using C0_is j0_notin unfolding active_subset_def by simp
   have step_n: "lnth Ns n \<leadsto>GC lnth Ns (Suc n)"
     using deriv chain_lnth_rel n_in unfolding nj_set_def by blast
   have "\<exists>N C L M. (lnth Ns n = N \<union> {(C, L)} \<and>
       lnth Ns (Suc n) = N \<union> {(C, active)} \<union> M \<and> L \<noteq> active \<and> active_subset M = {} \<and>
       no_labels.Inf_between (fst ` (active_subset N)) {C}
       \<subseteq> no_labels.Red_I (fst ` (N \<union> {(C, active)} \<union> M)))"
   proof -
     have proc_or_infer: "(\<exists>N1 N M N2 M'. lnth Ns n = N1 \<and> lnth Ns (Suc n) = N2 \<and> N1 = N \<union> M \<and>
          N2 = N \<union> M' \<and> M \<subseteq> Red_F (N \<union> M') \<and> active_subset M' = {}) \<or>
        (\<exists>N1 N C L N2 M. lnth Ns n = N1 \<and> lnth Ns (Suc n) = N2 \<and> N1 = N \<union> {(C, L)} \<and>
          N2 = N \<union> {(C, active)} \<union> M \<and> L \<noteq> active \<and> active_subset M = {} \<and>
          no_labels.Inf_between (fst ` (active_subset N)) {C} \<subseteq>
            no_labels.Red_I (fst ` (N \<union> {(C, active)} \<union> M)))"
       using step.simps[of "lnth Ns n" "lnth Ns (Suc n)"] step_n by blast
     show ?thesis
       using C0_in C0_notin proc_or_infer j0_in C0_is
       by (smt Un_iff active_subset_def mem_Collect_eq snd_conv sup_bot.right_neutral)
   qed
   then obtain N M L where inf_from_subs:
     "no_labels.Inf_between (fst ` (active_subset N)) {C0}
      \<subseteq> no_labels.Red_I (fst ` (N \<union> {(C0, active)} \<union> M))" and
     nth_d_is: "lnth Ns n = N \<union> {(C0, L)}" and
     suc_nth_d_is: "lnth Ns (Suc n) = N \<union> {(C0, active)} \<union> M" and
     l_not_active: "L \<noteq> active"
     using C0_in C0_notin j0_in C0_is using active_subset_def by fastforce
   have "j \<in> {0..<m} \<Longrightarrow> prems_of \<iota> ! j \<noteq> prems_of \<iota> ! j0 \<Longrightarrow> prems_of \<iota> ! j \<in> (active_subset N)" for j
   proof -
     fix j
     assume j_in: "j \<in> {0..<m}" and
       j_not_j0: "prems_of \<iota> ! j \<noteq> prems_of \<iota> ! j0"
     obtain nj where nj_len: "enat (Suc nj) < llength Ns" and
       nj_prems: "prems_of \<iota> ! j \<notin> active_subset (lnth Ns nj)" and
       nj_greater: "(\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (lnth Ns k))"
       using exist_nj j_in by blast
     then have "nj \<in> nj_set" unfolding nj_set_def using j_in by blast
     moreover have "nj \<noteq> n"
     proof (rule ccontr)
       assume "\<not> nj \<noteq> n"
       then have "prems_of \<iota> ! j = (C0, active)"
         using C0_in C0_notin step.simps[of "lnth Ns n" "lnth Ns (Suc n)"] step_n
         by (smt Un_iff nth_d_is suc_nth_d_is l_not_active active_subset_def insertCI insertE lessI
             mem_Collect_eq nj_greater nj_prems snd_conv suc_n_length)
       then show False using j_not_j0 C0_is by simp
     qed
     ultimately have "nj < n" using n_bigger by force
     then have "prems_of \<iota> ! j \<in> (active_subset (lnth Ns n))"
       using nj_greater n_in Suc_ile_eq dual_order.strict_implies_order unfolding nj_set_def by blast
     then show "prems_of \<iota> ! j \<in> (active_subset N)"
       using nth_d_is l_not_active unfolding active_subset_def by force
   qed
   then have "set (prems_of \<iota>) \<subseteq> active_subset N \<union> {(C0, active)}"
     using C0_prems_i C0_is m_def
     by (metis Un_iff atLeast0LessThan in_set_conv_nth insertCI lessThan_iff subrelI)
   moreover have "\<not> (set (prems_of \<iota>) \<subseteq> active_subset N - {(C0, active)})" using C0_prems_i by blast
   ultimately have "\<iota> \<in> Inf_between (active_subset N) {(C0, active)}"
     using i_in_inf_fl unfolding Inf_between_def Inf_from_def by blast
   then have "to_F \<iota> \<in> no_labels.Inf_between (fst ` (active_subset N)) {C0}"
     unfolding to_F_def Inf_between_def Inf_from_def
       no_labels.Inf_between_def no_labels.Inf_from_def using Inf_FL_to_Inf_F
     by force
   then have "to_F \<iota> \<in> no_labels.Red_I (fst ` (lnth Ns (Suc n)))"
     using suc_nth_d_is inf_from_subs by fastforce
   then have "\<forall>q \<in> Q. (\<G>_I_q q (to_F \<iota>) \<noteq> None \<and>
       the (\<G>_I_q q (to_F \<iota>)) \<subseteq> Red_I_q q (\<Union> (\<G>_F_q q ` fst ` lnth Ns (Suc n))))
       \<or> (\<G>_I_q q (to_F \<iota>) = None \<and>
       \<G>_F_q q (concl_of (to_F \<iota>)) \<subseteq> \<Union> (\<G>_F_q q ` fst ` lnth Ns (Suc n)) \<union>
         Red_F_q q (\<Union> (\<G>_F_q q ` fst ` lnth Ns (Suc n))))"
     unfolding to_F_def no_labels.Red_I_def no_labels.Red_I_\<G>_q_def by blast
   then have "\<iota> \<in> Red_I_\<G> (lnth Ns (Suc n))"
     using i_in_inf_fl unfolding Red_I_\<G>_def Red_I_\<G>_q_def by (simp add: to_F_def)
   then show "\<iota> \<in> Sup_llist (lmap Red_I_\<G> Ns)"
     unfolding Sup_llist_def using suc_n_length by auto
 qed
 
 theorem gc_complete_Liminf:
   assumes
     deriv: "chain (\<leadsto>GC) Ns" and
     init_state: "active_subset (lhd Ns) = {}" and
     final_state: "passive_subset (Liminf_llist Ns) = {}" and
     b_in: "B \<in> Bot_F" and
     bot_entailed: "no_labels.entails_\<G> (fst ` lhd Ns) {B}"
   shows "\<exists>BL \<in> Bot_FL. BL \<in> Liminf_llist Ns"
 proof -
   note lhd_is = lhd_conv_lnth[OF chain_not_lnull[OF deriv]]
   have labeled_b_in: "(B, active) \<in> Bot_FL" using b_in by simp
   have labeled_bot_entailed: "entails_\<G>_L (lhd Ns) {(B, active)}"
     using labeled_entailment_lifting bot_entailed lhd_is by fastforce
   have fair: "fair Ns" using gc_fair[OF deriv init_state final_state] .
   then show ?thesis
     using dynamically_complete_Liminf[OF labeled_b_in gc_to_red[OF deriv] fair
         labeled_bot_entailed]
     by blast
 qed
 
 (* thm:gc-completeness *)
 theorem gc_complete:
   assumes
     deriv: "chain (\<leadsto>GC) Ns" and
     init_state: "active_subset (lhd Ns) = {}" and
     final_state: "passive_subset (Liminf_llist Ns) = {}" and
     b_in: "B \<in> Bot_F" and
     bot_entailed: "no_labels.entails_\<G> (fst ` lhd Ns) {B}"
   shows "\<exists>i. enat i < llength Ns \<and> (\<exists>BL \<in> Bot_FL. BL \<in> lnth Ns i)"
 proof -
   note lhd_is = lhd_conv_lnth[OF chain_not_lnull[OF deriv]]
   have "\<exists>BL\<in>Bot_FL. BL \<in> Liminf_llist Ns"
     using assms by (rule gc_complete_Liminf)
   then show ?thesis
     unfolding Liminf_llist_def by auto
 qed
 
 end
 
 
 subsection \<open>Lazy Given Clause Procedure\<close>
 
 locale lazy_given_clause = given_clause_basis Bot_F Inf_F Bot_G Q entails_q Inf_G_q Red_I_q
   Red_F_q \<G>_F_q \<G>_I_q Inf_FL Equiv_F Prec_F Prec_L active
   for
     Bot_F :: "'f set" and
     Inf_F :: "'f inference set" and
     Bot_G :: "'g set" and
     Q :: "'q set" and
     entails_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set \<Rightarrow> bool" and
     Inf_G_q :: \<open>'q \<Rightarrow> 'g inference set\<close> and
     Red_I_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g inference set" and
     Red_F_q :: "'q \<Rightarrow> 'g set \<Rightarrow> 'g set" and
     \<G>_F_q :: "'q \<Rightarrow> 'f \<Rightarrow> 'g set"  and
     \<G>_I_q :: "'q \<Rightarrow> 'f inference \<Rightarrow> 'g inference set option" and
     Inf_FL :: \<open>('f \<times> 'l) inference set\<close> and
     Equiv_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<doteq>" 50) and
     Prec_F :: "'f \<Rightarrow> 'f \<Rightarrow> bool" (infix "\<prec>\<cdot>" 50) and
     Prec_L :: "'l \<Rightarrow> 'l \<Rightarrow> bool" (infix "\<sqsubset>L" 50) and
     active :: 'l
 begin
 
 inductive step :: "'f inference set \<times> ('f \<times> 'l) set \<Rightarrow>
   'f inference set \<times> ('f \<times> 'l) set \<Rightarrow> bool" (infix "\<leadsto>LGC" 50) where
   process: "N1 = N \<union> M \<Longrightarrow> N2 = N \<union> M' \<Longrightarrow> M \<subseteq> Red_F (N \<union> M') \<Longrightarrow>
     active_subset M' = {} \<Longrightarrow> (T, N1) \<leadsto>LGC (T, N2)" |
   schedule_infer: "T2 = T1 \<union> T' \<Longrightarrow> N1 = N \<union> {(C, L)} \<Longrightarrow> N2 = N \<union> {(C, active)} \<Longrightarrow>
     L \<noteq> active \<Longrightarrow> T' = no_labels.Inf_between (fst ` (active_subset N)) {C} \<Longrightarrow>
     (T1, N1) \<leadsto>LGC (T2, N2)" |
   compute_infer: "T1 = T2 \<union> {\<iota>} \<Longrightarrow> N2 = N1 \<union> M \<Longrightarrow> active_subset M = {} \<Longrightarrow>
     \<iota> \<in> no_labels.Red_I (fst ` (N1 \<union> M)) \<Longrightarrow> (T1, N1) \<leadsto>LGC (T2, N2)" |
   delete_orphans: "T1 = T2 \<union> T' \<Longrightarrow>
     T' \<inter> no_labels.Inf_from (fst ` (active_subset N)) = {} \<Longrightarrow> (T1, N) \<leadsto>LGC (T2, N)"
 
 lemma premise_free_inf_always_from: "\<iota> \<in> Inf_F \<Longrightarrow> prems_of \<iota> = [] \<Longrightarrow> \<iota> \<in> no_labels.Inf_from N"
   unfolding no_labels.Inf_from_def by simp
 
 lemma one_step_equiv: "(T1, N1) \<leadsto>LGC (T2, N2) \<Longrightarrow> N1 \<rhd>L N2"
 proof (cases "(T1, N1)" "(T2, N2)" rule: step.cases)
   show "(T1, N1) \<leadsto>LGC (T2, N2) \<Longrightarrow> (T1, N1) \<leadsto>LGC (T2, N2)" by blast
 next
   fix N M M'
   assume
     n1_is: "N1 = N \<union> M" and
     n2_is: "N2 = N \<union> M'" and
     m_red: "M \<subseteq> Red_F (N \<union> M')"
   have "N1 - N2 \<subseteq> Red_F N2"
     using n1_is n2_is m_red by auto
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 next
   fix N C L M
   assume
     n1_is: "N1 = N \<union> {(C, L)}" and
     not_active: "L \<noteq> active" and
     n2_is: "N2 = N \<union> {(C, active)}"
   have "(C, active) \<in> N2" using n2_is by auto
   moreover have "C \<preceq>\<cdot> C" by (metis equivp_def equiv_equiv_F)
   moreover have "active \<sqsubset>L L" using active_minimal[OF not_active] .
   ultimately have "{(C, L)} \<subseteq> Red_F N2"
     using red_labeled_clauses by blast
   then have "N1 - N2 \<subseteq> Red_F N2"
     using std_Red_F_eq using n1_is n2_is by blast
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 next
   fix M
   assume
     n2_is: "N2 = N1 \<union> M"
   have "N1 - N2 \<subseteq> Red_F N2"
     using n2_is by blast
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 next
   assume n2_is: "N2 = N1"
   have "N1 - N2 \<subseteq> Red_F N2"
     using n2_is by blast
   then show "N1 \<rhd>L N2"
     unfolding derive.simps by blast
 qed
 
 (* lem:lgc-derivations-are-red-derivations *)
 lemma lgc_to_red: "chain (\<leadsto>LGC) Ns \<Longrightarrow> chain (\<rhd>L) (lmap snd Ns)"
   using one_step_equiv Lazy_List_Chain.chain_mono by (smt chain_lmap prod.collapse)
 
 (* lem:fair-lgc-derivations *)
 lemma lgc_fair:
   assumes
     deriv: "chain (\<leadsto>LGC) Ns" and
     init_state: "active_subset (snd (lhd Ns)) = {}" and
     final_state: "passive_subset (Liminf_llist (lmap snd Ns)) = {}" and
     no_prems_init_active: "\<forall>\<iota> \<in> Inf_F. prems_of \<iota> = [] \<longrightarrow> \<iota> \<in> fst (lhd Ns)" and
     final_schedule: "Liminf_llist (lmap fst Ns) = {}"
   shows "fair (lmap snd Ns)"
   unfolding fair_def
 proof
   fix \<iota>
   assume i_in: "\<iota> \<in> Inf_from (Liminf_llist (lmap snd Ns))"
   note lhd_is = lhd_conv_lnth[OF chain_not_lnull[OF deriv]]
   have i_in_inf_fl: "\<iota> \<in> Inf_FL" using i_in unfolding Inf_from_def by blast
   have "Liminf_llist (lmap snd Ns) = active_subset (Liminf_llist (lmap snd Ns))"
     using final_state unfolding passive_subset_def active_subset_def by blast
   then have i_in2: "\<iota> \<in> Inf_from (active_subset (Liminf_llist (lmap snd Ns)))"
     using i_in by simp
   define m where "m = length (prems_of \<iota>)"
   then have m_def_F: "m = length (prems_of (to_F \<iota>))" unfolding to_F_def by simp
   have i_in_F: "to_F \<iota> \<in> Inf_F"
     using i_in Inf_FL_to_Inf_F unfolding Inf_from_def to_F_def by blast
   have exist_nj: "\<forall>j \<in> {0..<m}. (\<exists>nj. enat (Suc nj) < llength Ns \<and>
       prems_of \<iota> ! j \<notin> active_subset (snd (lnth Ns nj)) \<and>
       (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k))))"
   proof clarify
     fix j
     assume j_in: "j \<in> {0..<m}"
     then obtain C where c_is: "(C, active) = prems_of \<iota> ! j"
       using i_in2 unfolding m_def Inf_from_def active_subset_def
       by (smt Collect_mem_eq Collect_mono_iff atLeastLessThan_iff nth_mem old.prod.exhaust snd_conv)
     then have "(C, active) \<in> Liminf_llist (lmap snd Ns)"
       using j_in i_in unfolding m_def Inf_from_def by force
     then obtain nj where nj_is: "enat nj < llength Ns" and
       c_in2: "(C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns}))"
       unfolding Liminf_llist_def using init_state by fastforce
     then have c_in3: "\<forall>k. k \<ge> nj \<longrightarrow> enat k < llength Ns \<longrightarrow> (C, active) \<in> snd (lnth Ns k)" by blast
     have nj_pos: "nj > 0" using init_state c_in2 nj_is unfolding active_subset_def lhd_is by fastforce
     obtain nj_min where nj_min_is: "nj_min = (LEAST nj. enat nj < llength Ns \<and>
         (C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns})))" by blast
     then have in_allk: "\<forall>k. k \<ge> nj_min \<longrightarrow> enat k < llength Ns \<longrightarrow> (C, active) \<in> snd (lnth Ns k)"
       using c_in3 nj_is c_in2 INT_E LeastI_ex
       by (smt INT_iff INT_simps(10) c_is image_eqI mem_Collect_eq)
     have njm_smaller_D: "enat nj_min < llength Ns"
       using nj_min_is
       by (smt LeastI_ex \<open>\<And>thesis. (\<And>nj. \<lbrakk>enat nj < llength Ns;
           (C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns}))\<rbrakk> \<Longrightarrow> thesis) \<Longrightarrow> thesis\<close>)
     have "nj_min > 0"
       using nj_is c_in2 nj_pos nj_min_is lhd_is
       by (metis (mono_tags, lifting) active_subset_def emptyE in_allk init_state mem_Collect_eq
           not_less snd_conv zero_enat_def chain_length_pos[OF deriv])
     then obtain njm_prec where nj_prec_is: "Suc njm_prec = nj_min" using gr0_conv_Suc by auto
     then have njm_prec_njm: "njm_prec < nj_min" by blast
     then have njm_prec_njm_enat: "enat njm_prec < enat nj_min" by simp
     have njm_prec_smaller_d: "njm_prec < llength Ns"
       by (rule less_trans[OF njm_prec_njm_enat njm_smaller_D])
     have njm_prec_all_suc: "\<forall>k>njm_prec. enat k < llength Ns \<longrightarrow> (C, active) \<in> snd (lnth Ns k)"
       using nj_prec_is in_allk by simp
     have notin_njm_prec: "(C, active) \<notin> snd (lnth Ns njm_prec)"
     proof (rule ccontr)
       assume "\<not> (C, active) \<notin> snd (lnth Ns njm_prec)"
       then have absurd_hyp: "(C, active) \<in> snd (lnth Ns njm_prec)" by simp
       have prec_smaller: "enat njm_prec < llength Ns" using nj_min_is nj_prec_is
         by (smt LeastI_ex Suc_leD \<open>\<And>thesis. (\<And>nj. \<lbrakk>enat nj < llength Ns;
             (C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. nj \<le> k \<and> enat k < llength Ns}))\<rbrakk> \<Longrightarrow> thesis) \<Longrightarrow> thesis\<close>
             enat_ord_simps(1) le_eq_less_or_eq le_less_trans)
       have "(C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns}))"
       proof -
         {
           fix k
           assume k_in: "njm_prec \<le> k \<and> enat k < llength Ns"
           have "k = njm_prec \<Longrightarrow> (C, active) \<in> snd (lnth Ns k)" using absurd_hyp by simp
           moreover have "njm_prec < k \<Longrightarrow> (C, active) \<in> snd (lnth Ns k)"
             using nj_prec_is in_allk k_in by simp
           ultimately have "(C, active) \<in> snd (lnth Ns k)" using k_in by fastforce
         }
         then show "(C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns}))"
           by blast
       qed
       then have "enat njm_prec < llength Ns \<and>
           (C, active) \<in> \<Inter> (snd ` (lnth Ns ` {k. njm_prec \<le> k \<and> enat k < llength Ns}))"
         using prec_smaller by blast
       then show False
         using nj_min_is nj_prec_is Orderings.wellorder_class.not_less_Least njm_prec_njm by blast
     qed
     then have notin_active_subs_njm_prec: "(C, active) \<notin> active_subset (snd (lnth Ns njm_prec))"
       unfolding active_subset_def by blast
     then show "\<exists>nj. enat (Suc nj) < llength Ns \<and> prems_of \<iota> ! j \<notin> active_subset (snd (lnth Ns nj)) \<and>
         (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))"
       using c_is njm_prec_all_suc njm_prec_smaller_d by (metis (mono_tags, lifting)
           active_subset_def mem_Collect_eq nj_prec_is njm_smaller_D snd_conv)
   qed
   define nj_set where "nj_set = {nj. (\<exists>j\<in>{0..<m}. enat (Suc nj) < llength Ns \<and>
       prems_of \<iota> ! j \<notin> active_subset (snd (lnth Ns nj)) \<and>
       (\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow> prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k))))}"
   {
     assume m_null: "m = 0"
     then have "enat 0 < llength Ns \<and> to_F \<iota> \<in> fst (lhd Ns)"
       using no_prems_init_active i_in_F m_def_F zero_enat_def chain_length_pos[OF deriv] by auto
     then have "\<exists>n. enat n < llength Ns \<and> to_F \<iota> \<in> fst (lnth Ns n)"
       unfolding lhd_is by blast
   }
   moreover {
     assume m_pos: "m > 0"
     have nj_not_empty: "nj_set \<noteq> {}"
     proof -
       have zero_in: "0 \<in> {0..<m}" using m_pos by simp
       then obtain n0 where "enat (Suc n0) < llength Ns" and
         "prems_of \<iota> ! 0 \<notin> active_subset (snd (lnth Ns n0))" and
         "\<forall>k>n0. enat k < llength Ns \<longrightarrow> prems_of \<iota> ! 0 \<in> active_subset (snd (lnth Ns k))"
         using exist_nj by fast
       then have "n0 \<in> nj_set" unfolding nj_set_def using zero_in by blast
       then show "nj_set \<noteq> {}" by auto
     qed
     have nj_finite: "finite nj_set"
       using all_ex_finite_set[OF exist_nj] by (metis (no_types, lifting) Suc_ile_eq
           dual_order.strict_implies_order linorder_neqE_nat nj_set_def)
     have "\<exists>n \<in> nj_set. \<forall>nj \<in> nj_set. nj \<le> n"
       using nj_not_empty nj_finite using Max_ge Max_in by blast
     then obtain n where n_in: "n \<in> nj_set" and n_bigger: "\<forall>nj \<in> nj_set. nj \<le> n" by blast
     then obtain j0 where j0_in: "j0 \<in> {0..<m}" and suc_n_length: "enat (Suc n) < llength Ns" and
       j0_notin: "prems_of \<iota> ! j0 \<notin> active_subset (snd (lnth Ns n))" and
       j0_allin: "(\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
           prems_of \<iota> ! j0 \<in> active_subset (snd (lnth Ns k)))"
       unfolding nj_set_def by blast
     obtain C0 where C0_is: "prems_of \<iota> ! j0 = (C0, active)"
       using j0_in i_in2 unfolding m_def Inf_from_def active_subset_def
       by (smt Collect_mem_eq Collect_mono_iff atLeastLessThan_iff nth_mem old.prod.exhaust snd_conv)
     then have C0_prems_i: "(C0, active) \<in> set (prems_of \<iota>)" using in_set_conv_nth j0_in m_def by force
     have C0_in: "(C0, active) \<in> (snd (lnth Ns (Suc n)))"
       using C0_is j0_allin suc_n_length by (simp add: active_subset_def)
     have C0_notin: "(C0, active) \<notin> (snd (lnth Ns n))"
       using C0_is j0_notin unfolding active_subset_def by simp
     have step_n: "lnth Ns n \<leadsto>LGC lnth Ns (Suc n)"
       using deriv chain_lnth_rel n_in unfolding nj_set_def by blast
     have is_scheduled: "\<exists>T2 T1 T' N1 N C L N2. lnth Ns n = (T1, N1) \<and> lnth Ns (Suc n) = (T2, N2) \<and>
         T2 = T1 \<union> T' \<and> N1 = N \<union> {(C, L)} \<and> N2 = N \<union> {(C, active)} \<and> L \<noteq> active \<and>
         T' = no_labels.Inf_between (fst ` active_subset N) {C}"
       using step.simps[of "lnth Ns n" "lnth Ns (Suc n)"] step_n C0_in C0_notin
       unfolding active_subset_def by fastforce
     then obtain T2 T1 T' N1 N L N2 where nth_d_is: "lnth Ns n = (T1, N1)" and
       suc_nth_d_is: "lnth Ns (Suc n) = (T2, N2)" and t2_is: "T2 = T1 \<union> T'" and
       n1_is: "N1 = N \<union> {(C0, L)}" "N2 = N \<union> {(C0, active)}" and
       l_not_active: "L \<noteq> active" and
       tp_is: "T' = no_labels.Inf_between (fst ` active_subset N) {C0}"
       using C0_in C0_notin j0_in C0_is using active_subset_def by fastforce
     have "j \<in> {0..<m} \<Longrightarrow> prems_of \<iota> ! j \<noteq> prems_of \<iota> ! j0 \<Longrightarrow> prems_of \<iota> ! j \<in> (active_subset N)"
       for j
     proof -
       fix j
       assume j_in: "j \<in> {0..<m}" and
         j_not_j0: "prems_of \<iota> ! j \<noteq> prems_of \<iota> ! j0"
       obtain nj where nj_len: "enat (Suc nj) < llength Ns" and
         nj_prems: "prems_of \<iota> ! j \<notin> active_subset (snd (lnth Ns nj))" and
         nj_greater: "(\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow>
             prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))"
         using exist_nj j_in by blast
       then have "nj \<in> nj_set" unfolding nj_set_def using j_in by blast
       moreover have "nj \<noteq> n"
       proof (rule ccontr)
         assume "\<not> nj \<noteq> n"
         then have "prems_of \<iota> ! j = (C0, active)"
           using C0_in C0_notin step.simps[of "lnth Ns n" "lnth Ns (Suc n)"] step_n
             active_subset_def is_scheduled nj_greater nj_prems suc_n_length by auto
         then show False using j_not_j0 C0_is by simp
       qed
       ultimately have "nj < n" using n_bigger by force
       then have "prems_of \<iota> ! j \<in> (active_subset (snd (lnth Ns n)))"
         using nj_greater n_in Suc_ile_eq dual_order.strict_implies_order
         unfolding nj_set_def by blast
       then show "prems_of \<iota> ! j \<in> (active_subset N)"
         using nth_d_is l_not_active n1_is unfolding active_subset_def by force
     qed
     then have prems_i_active: "set (prems_of \<iota>) \<subseteq> active_subset N \<union> {(C0, active)}"
       using C0_prems_i C0_is m_def
       by (metis Un_iff atLeast0LessThan in_set_conv_nth insertCI lessThan_iff subrelI)
     moreover have "\<not> (set (prems_of \<iota>) \<subseteq> active_subset N - {(C0, active)})" using C0_prems_i by blast
     ultimately have "\<iota> \<in> Inf_between (active_subset N) {(C0, active)}"
       using i_in_inf_fl prems_i_active unfolding Inf_between_def Inf_from_def by blast
     then have "to_F \<iota> \<in> no_labels.Inf_between (fst ` (active_subset N)) {C0}"
       unfolding to_F_def Inf_between_def Inf_from_def
         no_labels.Inf_between_def no_labels.Inf_from_def
       using Inf_FL_to_Inf_F by force
     then have i_in_t2: "to_F \<iota> \<in> T2" using tp_is t2_is by simp
     have "j \<in> {0..<m} \<Longrightarrow> (\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
         prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))" for j
     proof (cases "j = j0")
       case True
       assume "j = j0"
       then show "(\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
           prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))" using j0_allin by simp
     next
       case False
       assume j_in: "j \<in> {0..<m}" and
         "j \<noteq> j0"
       obtain nj where nj_len: "enat (Suc nj) < llength Ns" and
         nj_prems: "prems_of \<iota> ! j \<notin> active_subset (snd (lnth Ns nj))" and
         nj_greater: "(\<forall>k. k > nj \<longrightarrow> enat k < llength Ns \<longrightarrow>
             prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))"
         using exist_nj j_in by blast
       then have "nj \<in> nj_set" unfolding nj_set_def using j_in by blast
       then show "(\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
           prems_of \<iota> ! j \<in> active_subset (snd (lnth Ns k)))"
         using nj_greater n_bigger by auto
     qed
     then have allj_allk: "(\<forall>c\<in> set (prems_of \<iota>). (\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
         c \<in> active_subset (snd (lnth Ns k))))"
       using m_def by (metis atLeast0LessThan in_set_conv_nth lessThan_iff)
     have "\<forall>c\<in> set (prems_of \<iota>). snd c = active"
       using prems_i_active unfolding active_subset_def by auto
     then have ex_n_i_in: "\<exists>n. enat (Suc n) < llength Ns \<and> to_F \<iota> \<in> fst (lnth Ns (Suc n)) \<and>
         (\<forall>c\<in> set (prems_of \<iota>). snd c = active) \<and>
         (\<forall>c\<in> set (prems_of \<iota>). (\<forall>k. k > n \<longrightarrow> enat k < llength Ns \<longrightarrow>
           c \<in> active_subset (snd (lnth Ns k))))"
       using allj_allk i_in_t2 suc_nth_d_is fstI n_in nj_set_def
       by auto
     then have "\<exists>n. enat n < llength Ns \<and> to_F \<iota> \<in> fst (lnth Ns n) \<and>
         (\<forall>c\<in> set (prems_of \<iota>). snd c = active) \<and> (\<forall>c\<in> set (prems_of \<iota>). (\<forall>k. k \<ge> n \<longrightarrow>
           enat k < llength Ns \<longrightarrow> c \<in> active_subset (snd (lnth Ns k))))"
       by auto
   }
   ultimately obtain n T2 N2 where i_in_suc_n: "to_F \<iota> \<in> fst (lnth Ns n)" and
     all_prems_active_after: "m > 0 \<Longrightarrow> (\<forall>c\<in> set (prems_of \<iota>). (\<forall>k. k \<ge> n \<longrightarrow> enat k < llength Ns \<longrightarrow>
                   c \<in> active_subset (snd (lnth Ns k))))" and
     suc_n_length: "enat n < llength Ns" and suc_nth_d_is: "lnth Ns n = (T2, N2)"
     by (metis less_antisym old.prod.exhaust zero_less_Suc)
   then have i_in_t2: "to_F \<iota> \<in> T2" by simp
   have "\<exists>p\<ge>n. enat (Suc p) < llength Ns \<and> to_F \<iota> \<in> (fst (lnth Ns p)) \<and> to_F \<iota> \<notin> (fst (lnth Ns (Suc p)))"
   proof (rule ccontr)
     assume
       contra: "\<not> (\<exists>p\<ge>n. enat (Suc p) < llength Ns \<and> to_F \<iota> \<in> (fst (lnth Ns p)) \<and>
                      to_F \<iota> \<notin> (fst (lnth Ns (Suc p))))"
     then have i_in_suc: "p0 \<ge> n \<Longrightarrow> enat (Suc p0) < llength Ns \<Longrightarrow> to_F \<iota> \<in> (fst (lnth Ns p0)) \<Longrightarrow>
         to_F \<iota> \<in> (fst (lnth Ns (Suc p0)))" for p0
       by blast
     have "p0 \<ge> n \<Longrightarrow> enat p0 < llength Ns \<Longrightarrow> to_F \<iota> \<in> (fst (lnth Ns p0))" for p0
     proof (induction rule: nat_induct_at_least)
       case base
       then show ?case using i_in_t2 suc_nth_d_is
         by simp
     next
       case (Suc p0)
       assume p_bigger_n: "n \<le> p0" and
         induct_hyp: "enat p0 < llength Ns \<Longrightarrow> to_F \<iota> \<in> fst (lnth Ns p0)" and
         sucsuc_smaller_d: "enat (Suc p0) < llength Ns"
       have suc_p_bigger_n: "n \<le> p0" using p_bigger_n by simp
       have suc_smaller_d: "enat p0 < llength Ns"
         using sucsuc_smaller_d Suc_ile_eq dual_order.strict_implies_order by blast
       then have "to_F \<iota> \<in> fst (lnth Ns p0)" using induct_hyp by blast
       then show ?case using i_in_suc[OF suc_p_bigger_n sucsuc_smaller_d] by blast
     qed
     then have i_in_all_bigger_n: "\<forall>j. j \<ge> n \<and> enat j < llength Ns \<longrightarrow> to_F \<iota> \<in> (fst (lnth Ns j))"
       by presburger
     have "llength (lmap fst Ns) = llength Ns" by force
     then have "to_F \<iota> \<in> \<Inter> (lnth (lmap fst Ns) ` {j. n \<le> j \<and> enat j < llength (lmap fst Ns)})"
       using i_in_all_bigger_n using Suc_le_D by auto
     then have "to_F \<iota> \<in> Liminf_llist (lmap fst Ns)"
       unfolding Liminf_llist_def using suc_n_length by auto
     then show False using final_schedule by fast
   qed
   then obtain p where p_greater_n: "p \<ge> n" and p_smaller_d: "enat (Suc p) < llength Ns" and
     i_in_p: "to_F \<iota> \<in> (fst (lnth Ns p))" and i_notin_suc_p: "to_F \<iota> \<notin> (fst (lnth Ns (Suc p)))"
     by blast
   have p_neq_n: "Suc p \<noteq> n" using i_notin_suc_p i_in_suc_n by blast
   have step_p: "lnth Ns p \<leadsto>LGC lnth Ns (Suc p)" using deriv p_smaller_d chain_lnth_rel by blast
   then have "\<exists>T1 T2 \<iota> N2 N1 M. lnth Ns p = (T1, N1) \<and> lnth Ns (Suc p) = (T2, N2) \<and>
       T1 = T2 \<union> {\<iota>} \<and> N2 = N1 \<union> M \<and> active_subset M = {} \<and>
       \<iota> \<in> no_labels.Red_I_\<G> (fst ` (N1 \<union> M))"
   proof -
     have ci_or_do: "(\<exists>T1 T2 \<iota> N2 N1 M. lnth Ns p = (T1, N1) \<and> lnth Ns (Suc p) = (T2, N2) \<and>
         T1 = T2 \<union> {\<iota>} \<and> N2 = N1 \<union> M \<and> active_subset M = {} \<and>
         \<iota> \<in> no_labels.Red_I_\<G> (fst ` (N1 \<union> M))) \<or>
         (\<exists>T1 T2 T' N. lnth Ns p = (T1, N) \<and> lnth Ns (Suc p) = (T2, N) \<and>
         T1 = T2 \<union> T' \<and> T' \<inter> no_labels.Inf_from (fst ` active_subset N) = {})"
       using step.simps[of "lnth Ns p" "lnth Ns (Suc p)"] step_p i_in_p i_notin_suc_p by fastforce
     then have p_greater_n_strict: "n < Suc p"
       using suc_nth_d_is p_greater_n i_in_t2 i_notin_suc_p le_eq_less_or_eq by force
     have "m > 0 \<Longrightarrow> j \<in> {0..<m} \<Longrightarrow> prems_of (to_F \<iota>) ! j \<in> fst ` active_subset (snd (lnth Ns p))"
       for j
     proof -
       fix j
       assume
         m_pos: "m > 0" and
         j_in: "j \<in> {0..<m}"
       then have "prems_of \<iota> ! j \<in> (active_subset (snd (lnth Ns p)))"
         using all_prems_active_after[OF m_pos] p_smaller_d m_def p_greater_n p_neq_n
         by (meson Suc_ile_eq atLeastLessThan_iff dual_order.strict_implies_order nth_mem
             p_greater_n_strict)
       then have "fst (prems_of \<iota> ! j) \<in> fst ` active_subset (snd (lnth Ns p))"
         by blast
       then show "prems_of (to_F \<iota>) ! j \<in> fst ` active_subset (snd (lnth Ns p))"
         unfolding to_F_def using j_in m_def by simp
     qed
     then have prems_i_active_p: "m > 0 \<Longrightarrow>
         to_F \<iota> \<in> no_labels.Inf_from (fst ` active_subset (snd (lnth Ns p)))"
       using i_in_F unfolding no_labels.Inf_from_def
       by (smt atLeast0LessThan in_set_conv_nth lessThan_iff m_def_F mem_Collect_eq subsetI)
     have "m = 0 \<Longrightarrow> (\<exists>T1 T2 \<iota> N2 N1 M. lnth Ns p = (T1, N1) \<and> lnth Ns (Suc p) = (T2, N2) \<and>
         T1 = T2 \<union> {\<iota>} \<and> N2 = N1 \<union> M \<and> active_subset M = {} \<and>
         \<iota> \<in> no_labels.Red_I_\<G> (fst ` (N1 \<union> M)))"
       using ci_or_do premise_free_inf_always_from[of "to_F \<iota>" "fst ` active_subset _", OF i_in_F]
         m_def i_in_p i_notin_suc_p m_def_F by auto
     then show "(\<exists>T1 T2 \<iota> N2 N1 M. lnth Ns p = (T1, N1) \<and> lnth Ns (Suc p) = (T2, N2) \<and>
         T1 = T2 \<union> {\<iota>} \<and> N2 = N1 \<union> M \<and> active_subset M = {} \<and>
         \<iota> \<in> no_labels.Red_I_\<G> (fst ` (N1 \<union> M)))"
       using ci_or_do i_in_p i_notin_suc_p prems_i_active_p unfolding active_subset_def by force
   qed
   then obtain T1p T2p N1p N2p Mp where  "lnth Ns p = (T1p, N1p)" and
     suc_p_is: "lnth Ns (Suc p) = (T2p, N2p)" and "T1p = T2p \<union> {to_F \<iota>}" and "T2p \<inter> {to_F \<iota>} = {}" and
     n2p_is: "N2p = N1p \<union> Mp"and "active_subset Mp = {}" and
     i_in_red_inf: "to_F \<iota> \<in> no_labels.Red_I_\<G>
         (fst ` (N1p \<union> Mp))"
     using i_in_p i_notin_suc_p by fastforce
   have "to_F \<iota> \<in> no_labels.Red_I (fst ` (snd (lnth Ns (Suc p))))"
     using i_in_red_inf suc_p_is n2p_is by fastforce
   then have "\<forall>q \<in> Q. (\<G>_I_q q (to_F \<iota>) \<noteq> None \<and>
       the (\<G>_I_q q (to_F \<iota>)) \<subseteq> Red_I_q q (\<Union> (\<G>_F_q q ` fst ` snd (lnth Ns (Suc p)))))
       \<or> (\<G>_I_q q (to_F \<iota>) = None \<and>
       \<G>_F_q q (concl_of (to_F \<iota>)) \<subseteq> \<Union> (\<G>_F_q q ` fst ` snd (lnth Ns (Suc p))) \<union>
         Red_F_q q (\<Union> (\<G>_F_q q ` fst ` snd (lnth Ns (Suc p)))))"
     unfolding to_F_def no_labels.Red_I_def no_labels.Red_I_\<G>_q_def by blast
   then have "\<iota> \<in> Red_I_\<G> (snd (lnth Ns (Suc p)))"
     using i_in_inf_fl unfolding Red_I_\<G>_def Red_I_\<G>_q_def by (simp add: to_F_def)
   then show "\<iota> \<in> Sup_llist (lmap Red_I_\<G> (lmap snd Ns))"
     unfolding Sup_llist_def using suc_n_length p_smaller_d by auto
 qed
 
 theorem lgc_complete_Liminf:
   assumes
     deriv: "chain (\<leadsto>LGC) Ns" and
     init_state: "active_subset (snd (lhd Ns)) = {}" and
     final_state: "passive_subset (Liminf_llist (lmap snd Ns)) = {}" and
     no_prems_init_active: "\<forall>\<iota> \<in> Inf_F. prems_of \<iota> = [] \<longrightarrow> \<iota> \<in> fst (lhd Ns)" and
     final_schedule: "Liminf_llist (lmap fst Ns) = {}" and
     b_in: "B \<in> Bot_F" and
     bot_entailed: "no_labels.entails_\<G> (fst ` snd (lhd Ns)) {B}"
   shows "\<exists>BL \<in> Bot_FL. BL \<in> Liminf_llist (lmap snd Ns)"
 proof -
   have labeled_b_in: "(B, active) \<in> Bot_FL" using b_in by simp
   have simp_snd_lmap: "lhd (lmap snd Ns) = snd (lhd Ns)"
     by (rule llist.map_sel(1)[OF chain_not_lnull[OF deriv]])
   have labeled_bot_entailed: "entails_\<G>_L (snd (lhd Ns)) {(B, active)}"
     using labeled_entailment_lifting bot_entailed by fastforce
   have "fair (lmap snd Ns)"
     using lgc_fair[OF deriv init_state final_state no_prems_init_active final_schedule] .
   then show ?thesis
     using dynamically_complete_Liminf labeled_b_in lgc_to_red[OF deriv]
       labeled_bot_entailed simp_snd_lmap std_Red_I_eq
     by presburger
 qed
 
 (* thm:lgc-completeness *)
 theorem lgc_complete:
   assumes
     deriv: "chain (\<leadsto>LGC) Ns" and
     init_state: "active_subset (snd (lhd Ns)) = {}" and
     final_state: "passive_subset (Liminf_llist (lmap snd Ns)) = {}" and
     no_prems_init_active: "\<forall>\<iota> \<in> Inf_F. prems_of \<iota> = [] \<longrightarrow> \<iota> \<in> fst (lhd Ns)" and
     final_schedule: "Liminf_llist (lmap fst Ns) = {}" and
     b_in: "B \<in> Bot_F" and
     bot_entailed: "no_labels.entails_\<G> (fst ` snd (lhd Ns)) {B}"
   shows "\<exists>i. enat i < llength Ns \<and> (\<exists>BL \<in> Bot_FL. BL \<in> snd (lnth Ns i))"
 proof -
   have "\<exists>BL\<in>Bot_FL. BL \<in> Liminf_llist (lmap snd Ns)"
     using assms by (rule lgc_complete_Liminf)
   then show ?thesis
     unfolding Liminf_llist_def by auto
 qed
 
 end
 
 end