diff --git a/thys/Word_Lib/Bits_Int.thy b/thys/Word_Lib/Bits_Int.thy
--- a/thys/Word_Lib/Bits_Int.thy
+++ b/thys/Word_Lib/Bits_Int.thy
@@ -1,1465 +1,1465 @@
 (*
  * Copyright Brian Huffman, PSU; Jeremy Dawson and Gerwin Klein, NICTA
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 section \<open>Bitwise Operations on integers\<close>
 
 theory Bits_Int
   imports
     "HOL-Library.Word"
     Traditional_Infix_Syntax
 begin
 
 subsection \<open>Implicit bit representation of \<^typ>\<open>int\<close>\<close>
 
 lemma bin_last_def:
   "(odd :: int \<Rightarrow> bool) w \<longleftrightarrow> w mod 2 = 1"
   by (fact odd_iff_mod_2_eq_one)
 
 lemma bin_last_numeral_simps [simp]:
   "\<not> odd (0 :: int)"
   "odd (1 :: int)"
   "odd (- 1 :: int)"
   "odd (Numeral1 :: int)"
   "\<not> odd (numeral (Num.Bit0 w) :: int)"
   "odd (numeral (Num.Bit1 w) :: int)"
   "\<not> odd (- numeral (Num.Bit0 w) :: int)"
   "odd (- numeral (Num.Bit1 w) :: int)"
   by simp_all
 
 lemma bin_rest_numeral_simps [simp]:
   "(\<lambda>k::int. k div 2) 0 = 0"
   "(\<lambda>k::int. k div 2) 1 = 0"
   "(\<lambda>k::int. k div 2) (- 1) = - 1"
   "(\<lambda>k::int. k div 2) Numeral1 = 0"
   "(\<lambda>k::int. k div 2) (numeral (Num.Bit0 w)) = numeral w"
   "(\<lambda>k::int. k div 2) (numeral (Num.Bit1 w)) = numeral w"
   "(\<lambda>k::int. k div 2) (- numeral (Num.Bit0 w)) = - numeral w"
   "(\<lambda>k::int. k div 2) (- numeral (Num.Bit1 w)) = - numeral (w + Num.One)"
   by simp_all
 
 lemma bin_rl_eqI: "\<lbrakk>(\<lambda>k::int. k div 2) x = (\<lambda>k::int. k div 2) y; odd x = odd y\<rbrakk> \<Longrightarrow> x = y"
   by (auto elim: oddE)
 
 lemma [simp]:
   shows bin_rest_lt0: "(\<lambda>k::int. k div 2) i < 0 \<longleftrightarrow> i < 0"
   and  bin_rest_ge_0: "(\<lambda>k::int. k div 2) i \<ge> 0 \<longleftrightarrow> i \<ge> 0"
   by auto
 
 lemma bin_rest_gt_0 [simp]: "(\<lambda>k::int. k div 2) x > 0 \<longleftrightarrow> x > 1"
   by auto
 
 
 subsection \<open>Bit projection\<close>
 
 lemma bin_nth_eq_iff: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) x = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y \<longleftrightarrow> x = y"
   by (simp add: bit_eq_iff fun_eq_iff)
 
 lemma bin_eqI:
   "x = y" if "\<And>n. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n \<longleftrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n"
   using that bin_nth_eq_iff [of x y] by (simp add: fun_eq_iff)
 
 lemma bin_eq_iff: "x = y \<longleftrightarrow> (\<forall>n. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n)"
   by (fact bit_eq_iff)
 
 lemma bin_nth_zero [simp]: "\<not> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) 0 n"
   by simp
 
 lemma bin_nth_1 [simp]: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) 1 n \<longleftrightarrow> n = 0"
   by (cases n) (simp_all add: bit_Suc)
 
 lemma bin_nth_minus1 [simp]: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (- 1) n"
   by (induction n) (simp_all add: bit_Suc)
 
 lemma bin_nth_numeral: "(\<lambda>k::int. k div 2) x = y \<Longrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x (numeral n) = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y (pred_numeral n)"
   by (simp add: numeral_eq_Suc bit_Suc)
 
 lemmas bin_nth_numeral_simps [simp] =
   bin_nth_numeral [OF bin_rest_numeral_simps(8)]
 
 lemmas bin_nth_simps =
   bit_0 bit_Suc bin_nth_zero bin_nth_minus1
   bin_nth_numeral_simps
 
 lemma nth_2p_bin: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (2 ^ n) m = (m = n)" \<comment> \<open>for use when simplifying with \<open>bin_nth_Bit\<close>\<close>
   by (auto simp add: bit_exp_iff)
 
 lemma nth_rest_power_bin: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (((\<lambda>k::int. k div 2) ^^ k) w) n = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w (n + k)"
   apply (induct k arbitrary: n)
    apply clarsimp
   apply clarsimp
   apply (simp only: bit_Suc [symmetric] add_Suc)
   done
 
 lemma bin_nth_numeral_unfold:
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral (num.Bit0 x)) n \<longleftrightarrow> n > 0 \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral x) (n - 1)"
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral (num.Bit1 x)) n \<longleftrightarrow> (n > 0 \<longrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral x) (n - 1))"
   by (cases n; simp)+
 
 
 subsection \<open>Truncating\<close>
 
 definition bin_sign :: "int \<Rightarrow> int"
   where "bin_sign k = (if k \<ge> 0 then 0 else - 1)"
 
 lemma bin_sign_simps [simp]:
   "bin_sign 0 = 0"
   "bin_sign 1 = 0"
   "bin_sign (- 1) = - 1"
   "bin_sign (numeral k) = 0"
   "bin_sign (- numeral k) = -1"
   by (simp_all add: bin_sign_def)
 
 lemma bin_sign_rest [simp]: "bin_sign ((\<lambda>k::int. k div 2) w) = bin_sign w"
   by (simp add: bin_sign_def)
 
 lemma bintrunc_mod2p: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w = w mod 2 ^ n"
   by (fact take_bit_eq_mod)
 
 lemma sbintrunc_mod2p: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w = (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n"
   by (simp add: bintrunc_mod2p signed_take_bit_eq_take_bit_shift)
 
 lemma sbintrunc_eq_take_bit:
   \<open>(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n k = take_bit (Suc n) (k + 2 ^ n) - 2 ^ n\<close>
   by (fact signed_take_bit_eq_take_bit_shift)
 
 lemma sign_bintr: "bin_sign ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = 0"
   by (simp add: bin_sign_def)
 
 lemma bintrunc_n_0: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n 0 = 0"
   by (fact take_bit_of_0)
 
 lemma sbintrunc_n_0: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n 0 = 0"
   by (fact signed_take_bit_of_0)
 
 lemma sbintrunc_n_minus1: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- 1) = -1"
   by (fact signed_take_bit_of_minus_1)
 
 lemma bintrunc_Suc_numeral:
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) 1 = 1"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- 1) = 1 + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- 1)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- numeral (w + Num.One))"
   by (simp_all add: take_bit_Suc)
 
 lemma sbintrunc_0_numeral [simp]:
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 0 1 = -1"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 0 (numeral (Num.Bit0 w)) = 0"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 0 (numeral (Num.Bit1 w)) = -1"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 0 (- numeral (Num.Bit0 w)) = 0"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 0 (- numeral (Num.Bit1 w)) = -1"
   by simp_all
 
 lemma sbintrunc_Suc_numeral:
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) 1 = 1"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- numeral (w + Num.One))"
   by (simp_all add: signed_take_bit_Suc)
 
 lemma bin_sign_lem: "(bin_sign ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin) = -1) = bit bin n"
   by (simp add: bin_sign_def)
 
 lemma nth_bintr: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w) n \<longleftrightarrow> n < m \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w n"
   by (fact bit_take_bit_iff)
 
 lemma nth_sbintr: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w) n = (if n < m then (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w n else (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w m)"
   by (simp add: bit_signed_take_bit_iff min_def)
 
 lemma bin_nth_Bit0:
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral (Num.Bit0 w)) n \<longleftrightarrow>
     (\<exists>m. n = Suc m \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral w) m)"
   using bit_double_iff [of \<open>numeral w :: int\<close> n]
   by (auto intro: exI [of _ \<open>n - 1\<close>])
 
 lemma bin_nth_Bit1:
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral (Num.Bit1 w)) n \<longleftrightarrow>
     n = 0 \<or> (\<exists>m. n = Suc m \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (numeral w) m)"
   using even_bit_succ_iff [of \<open>2 * numeral w :: int\<close> n]
     bit_double_iff [of \<open>numeral w :: int\<close> n]
   by auto
 
 lemma bintrunc_bintrunc_l: "n \<le> m \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by simp
 
 lemma sbintrunc_sbintrunc_l: "n \<le> m \<Longrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: min_def)
 
 lemma bintrunc_bintrunc_ge: "n \<le> m \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (rule bin_eqI) (auto simp: nth_bintr)
 
 lemma bintrunc_bintrunc_min [simp]: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (min m n) w"
   by (rule take_bit_take_bit)
 
 lemma sbintrunc_sbintrunc_min [simp]: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (min m n) w"
   by (rule signed_take_bit_signed_take_bit)
 
 lemmas sbintrunc_Suc_Pls =
   signed_take_bit_Suc [where a="0::int", simplified bin_last_numeral_simps bin_rest_numeral_simps]
 
 lemmas sbintrunc_Suc_Min =
   signed_take_bit_Suc [where a="-1::int", simplified bin_last_numeral_simps bin_rest_numeral_simps]
 
 lemmas sbintrunc_Sucs = sbintrunc_Suc_Pls sbintrunc_Suc_Min
   sbintrunc_Suc_numeral
 
 lemmas sbintrunc_Pls =
   signed_take_bit_0 [where a="0::int", simplified bin_last_numeral_simps bin_rest_numeral_simps]
 
 lemmas sbintrunc_Min =
   signed_take_bit_0 [where a="-1::int", simplified bin_last_numeral_simps bin_rest_numeral_simps]
 
 lemmas sbintrunc_0_simps =
   sbintrunc_Pls sbintrunc_Min
 
 lemmas sbintrunc_simps = sbintrunc_0_simps sbintrunc_Sucs
 
 lemma bintrunc_minus: "0 < n \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc (n - 1)) w = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by auto
 
 lemma sbintrunc_minus: "0 < n \<Longrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc (n - 1)) w = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by auto
 
 lemmas sbintrunc_minus_simps =
   sbintrunc_Sucs [THEN [2] sbintrunc_minus [symmetric, THEN trans]]
 
 lemma sbintrunc_BIT_I:
   \<open>0 < n \<Longrightarrow>
   (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) 0 = y \<Longrightarrow>
   (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n 0 = 2 * y\<close>
   by simp
 
 lemma sbintrunc_Suc_Is:
   \<open>(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- 1) = y \<Longrightarrow>
   (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) (- 1) = 1 + 2 * y\<close>
   by auto
 
 lemma sbintrunc_Suc_lem: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) x = y \<Longrightarrow> m = Suc n \<Longrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m x = y"
   by (rule ssubst)
 
 lemmas sbintrunc_Suc_Ialts =
   sbintrunc_Suc_Is [THEN sbintrunc_Suc_lem]
 
 lemma sbintrunc_bintrunc_lt: "m > n \<Longrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w) = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (rule bin_eqI) (auto simp: nth_sbintr nth_bintr)
 
 lemma bintrunc_sbintrunc_le: "m \<le> Suc n \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w"
   by (rule take_bit_signed_take_bit)
 
 lemmas bintrunc_sbintrunc [simp] = order_refl [THEN bintrunc_sbintrunc_le]
 lemmas sbintrunc_bintrunc [simp] = lessI [THEN sbintrunc_bintrunc_lt]
 lemmas bintrunc_bintrunc [simp] = order_refl [THEN bintrunc_bintrunc_l]
 lemmas sbintrunc_sbintrunc [simp] = order_refl [THEN sbintrunc_sbintrunc_l]
 
 lemma bintrunc_sbintrunc' [simp]: "0 < n \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) w) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (cases n) simp_all
 
 lemma sbintrunc_bintrunc' [simp]: "0 < n \<Longrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w) = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) w"
   by (cases n) simp_all
 
 lemma bin_sbin_eq_iff: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) x = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) y \<longleftrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y"
   apply (rule iffI)
    apply (rule box_equals [OF _ sbintrunc_bintrunc sbintrunc_bintrunc])
    apply simp
   apply (rule box_equals [OF _ bintrunc_sbintrunc bintrunc_sbintrunc])
   apply simp
   done
 
 lemma bin_sbin_eq_iff':
   "0 < n \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y \<longleftrightarrow> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) x = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) y"
   by (cases n) (simp_all add: bin_sbin_eq_iff)
 
 lemmas bintrunc_sbintruncS0 [simp] = bintrunc_sbintrunc' [unfolded One_nat_def]
 lemmas sbintrunc_bintruncS0 [simp] = sbintrunc_bintrunc' [unfolded One_nat_def]
 
 lemmas bintrunc_bintrunc_l' = le_add1 [THEN bintrunc_bintrunc_l]
 lemmas sbintrunc_sbintrunc_l' = le_add1 [THEN sbintrunc_sbintrunc_l]
 
 (* although bintrunc_minus_simps, if added to default simpset,
   tends to get applied where it's not wanted in developing the theories,
   we get a version for when the word length is given literally *)
 
 lemmas nat_non0_gr =
   trans [OF iszero_def [THEN Not_eq_iff [THEN iffD2]] refl]
 
 lemma bintrunc_numeral:
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) x = of_bool (odd x) + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (x div 2)"
   by (simp add: numeral_eq_Suc take_bit_Suc mod_2_eq_odd)
 
 lemma sbintrunc_numeral:
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) x = of_bool (odd x) + 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (x div 2)"
   by (simp add: numeral_eq_Suc signed_take_bit_Suc mod2_eq_if)
 
 lemma bintrunc_numeral_simps [simp]:
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (numeral (Num.Bit0 w)) =
     2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (numeral (Num.Bit1 w)) =
     1 + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (- numeral (Num.Bit0 w)) =
     2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (- numeral w)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (- numeral (Num.Bit1 w)) =
     1 + 2 * (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (- numeral (w + Num.One))"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) 1 = 1"
   by (simp_all add: bintrunc_numeral)
 
 lemma sbintrunc_numeral_simps [simp]:
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (numeral (Num.Bit0 w)) =
     2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (numeral (Num.Bit1 w)) =
     1 + 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (- numeral (Num.Bit0 w)) =
     2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (- numeral w)"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) (- numeral (Num.Bit1 w)) =
     1 + 2 * (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (pred_numeral k) (- numeral (w + Num.One))"
   "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (numeral k) 1 = 1"
   by (simp_all add: sbintrunc_numeral)
 
 lemma no_bintr_alt1: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n = (\<lambda>w. w mod 2 ^ n :: int)"
   by (rule ext) (rule bintrunc_mod2p)
 
 lemma range_bintrunc: "range ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n) = {i. 0 \<le> i \<and> i < 2 ^ n}"
   by (auto simp add: take_bit_eq_mod image_iff) (metis mod_pos_pos_trivial)
 
 lemma no_sbintr_alt2: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n = (\<lambda>w. (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n :: int)"
   by (rule ext) (simp add : sbintrunc_mod2p)
 
 lemma range_sbintrunc: "range ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n) = {i. - (2 ^ n) \<le> i \<and> i < 2 ^ n}"
 proof -
   have \<open>surj (\<lambda>k::int. k + 2 ^ n)\<close>
     by (rule surjI [of _ \<open>(\<lambda>k. k - 2 ^ n)\<close>]) simp
   moreover have \<open>(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n = ((\<lambda>k. k - 2 ^ n) \<circ> take_bit (Suc n) \<circ> (\<lambda>k. k + 2 ^ n))\<close>
     by (simp add: sbintrunc_eq_take_bit fun_eq_iff)
   ultimately show ?thesis
     apply (simp only: fun.set_map range_bintrunc)
     apply (auto simp add: image_iff)
     apply presburger
     done
 qed
 
 lemma sbintrunc_inc:
   \<open>k + 2 ^ Suc n \<le> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n k\<close> if \<open>k < - (2 ^ n)\<close>
   using that by (fact signed_take_bit_int_greater_eq)
 
 lemma sbintrunc_dec:
   \<open>(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n k \<le> k - 2 ^ (Suc n)\<close> if \<open>k \<ge> 2 ^ n\<close>
   using that by (fact signed_take_bit_int_less_eq)
 
 lemma bintr_ge0: "0 \<le> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: bintrunc_mod2p)
 
 lemma bintr_lt2p: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w < 2 ^ n"
   by (simp add: bintrunc_mod2p)
 
 lemma bintr_Min: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- 1) = 2 ^ n - 1"
   by (simp add: stable_imp_take_bit_eq)
 
 lemma sbintr_ge: "- (2 ^ n) \<le> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: sbintrunc_mod2p)
 
 lemma sbintr_lt: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w < 2 ^ n"
   by (simp add: sbintrunc_mod2p)
 
 lemma sign_Pls_ge_0: "bin_sign bin = 0 \<longleftrightarrow> bin \<ge> 0"
   for bin :: int
   by (simp add: bin_sign_def)
 
 lemma sign_Min_lt_0: "bin_sign bin = -1 \<longleftrightarrow> bin < 0"
   for bin :: int
   by (simp add: bin_sign_def)
 
 lemma bin_rest_trunc: "(\<lambda>k::int. k div 2) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - 1) ((\<lambda>k::int. k div 2) bin)"
   by (simp add: take_bit_rec [of n bin])
 
 lemma bin_rest_power_trunc:
   "((\<lambda>k::int. k div 2) ^^ k) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (n - k) (((\<lambda>k::int. k div 2) ^^ k) bin)"
   by (induct k) (auto simp: bin_rest_trunc)
 
 lemma bin_rest_trunc_i: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((\<lambda>k::int. k div 2) bin) = (\<lambda>k::int. k div 2) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) bin)"
   by (auto simp add: take_bit_Suc)
 
 lemma bin_rest_strunc: "(\<lambda>k::int. k div 2) ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (Suc n) bin) = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((\<lambda>k::int. k div 2) bin)"
   by (simp add: signed_take_bit_Suc)
 
 lemma bintrunc_rest [simp]: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((\<lambda>k::int. k div 2) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin)) = (\<lambda>k::int. k div 2) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin)"
   by (induct n arbitrary: bin) (simp_all add: take_bit_Suc)
 
 lemma sbintrunc_rest [simp]: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((\<lambda>k::int. k div 2) ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin)) = (\<lambda>k::int. k div 2) ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n bin)"
   by (induct n arbitrary: bin) (simp_all add: signed_take_bit_Suc mod2_eq_if)
 
 lemma bintrunc_rest': "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n \<circ> (\<lambda>k::int. k div 2) \<circ> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n = (\<lambda>k::int. k div 2) \<circ> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n"
   by (rule ext) auto
 
 lemma sbintrunc_rest': "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n \<circ> (\<lambda>k::int. k div 2) \<circ> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n = (\<lambda>k::int. k div 2) \<circ> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n"
   by (rule ext) auto
 
 lemma rco_lem: "f \<circ> g \<circ> f = g \<circ> f \<Longrightarrow> f \<circ> (g \<circ> f) ^^ n = g ^^ n \<circ> f"
   apply (rule ext)
   apply (induct_tac n)
    apply (simp_all (no_asm))
   apply (drule fun_cong)
   apply (unfold o_def)
   apply (erule trans)
   apply simp
   done
 
 lemmas rco_bintr = bintrunc_rest'
   [THEN rco_lem [THEN fun_cong], unfolded o_def]
 lemmas rco_sbintr = sbintrunc_rest'
   [THEN rco_lem [THEN fun_cong], unfolded o_def]
 
 
 subsection \<open>Splitting and concatenation\<close>
 
 definition bin_split :: \<open>nat \<Rightarrow> int \<Rightarrow> int \<times> int\<close>
   where [simp]: \<open>bin_split n k = (drop_bit n k, take_bit n k)\<close>
 
 lemma [code]:
   "bin_split (Suc n) w = (let (w1, w2) = bin_split n (w div 2) in (w1, of_bool (odd w) + 2 * w2))"
   "bin_split 0 w = (w, 0)"
   by (simp_all add: drop_bit_Suc take_bit_Suc mod_2_eq_odd)
 
 lemma bin_cat_eq_push_bit_add_take_bit:
   \<open>concat_bit n l k = push_bit n k + take_bit n l\<close>
   by (simp add: concat_bit_eq)
 
 lemma bin_sign_cat: "bin_sign ((\<lambda>k n l. concat_bit n l k) x n y) = bin_sign x"
 proof -
   have \<open>0 \<le> x\<close> if \<open>0 \<le> x * 2 ^ n + y mod 2 ^ n\<close>
   proof -
     have \<open>y mod 2 ^ n < 2 ^ n\<close>
       using pos_mod_bound [of \<open>2 ^ n\<close> y] by simp
     then have \<open>\<not> y mod 2 ^ n \<ge> 2 ^ n\<close>
       by (simp add: less_le)
     with that have \<open>x \<noteq> - 1\<close>
       by auto
     have *: \<open>- 1 \<le> (- (y mod 2 ^ n)) div 2 ^ n\<close>
       by (simp add: zdiv_zminus1_eq_if)
     from that have \<open>- (y mod 2 ^ n) \<le> x * 2 ^ n\<close>
       by simp
     then have \<open>(- (y mod 2 ^ n)) div 2 ^ n \<le> (x * 2 ^ n) div 2 ^ n\<close>
       using zdiv_mono1 zero_less_numeral zero_less_power by blast
     with * have \<open>- 1 \<le> x * 2 ^ n div 2 ^ n\<close> by simp
     with \<open>x \<noteq> - 1\<close> show ?thesis
       by simp
   qed
   then show ?thesis
     by (simp add: bin_sign_def not_le not_less bin_cat_eq_push_bit_add_take_bit push_bit_eq_mult take_bit_eq_mod)
 qed
 
 lemma bin_cat_assoc: "(\<lambda>k n l. concat_bit n l k) ((\<lambda>k n l. concat_bit n l k) x m y) n z = (\<lambda>k n l. concat_bit n l k) x (m + n) ((\<lambda>k n l. concat_bit n l k) y n z)"
   by (fact concat_bit_assoc)
 
 lemma bin_cat_assoc_sym: "(\<lambda>k n l. concat_bit n l k) x m ((\<lambda>k n l. concat_bit n l k) y n z) = (\<lambda>k n l. concat_bit n l k) ((\<lambda>k n l. concat_bit n l k) x (m - n) y) (min m n) z"
   by (fact concat_bit_assoc_sym)
 
 definition bin_rcat :: \<open>nat \<Rightarrow> int list \<Rightarrow> int\<close>
   where \<open>bin_rcat n = horner_sum (take_bit n) (2 ^ n) \<circ> rev\<close>
 
 lemma bin_rcat_eq_foldl:
   \<open>bin_rcat n = foldl (\<lambda>u v. (\<lambda>k n l. concat_bit n l k) u n v) 0\<close>
 proof
   fix ks :: \<open>int list\<close>
   show \<open>bin_rcat n ks = foldl (\<lambda>u v. (\<lambda>k n l. concat_bit n l k) u n v) 0 ks\<close>
     by (induction ks rule: rev_induct)
       (simp_all add: bin_rcat_def concat_bit_eq push_bit_eq_mult)
 qed
 
 fun bin_rsplit_aux :: "nat \<Rightarrow> nat \<Rightarrow> int \<Rightarrow> int list \<Rightarrow> int list"
   where "bin_rsplit_aux n m c bs =
     (if m = 0 \<or> n = 0 then bs
      else
       let (a, b) = bin_split n c
       in bin_rsplit_aux n (m - n) a (b # bs))"
 
 definition bin_rsplit :: "nat \<Rightarrow> nat \<times> int \<Rightarrow> int list"
   where "bin_rsplit n w = bin_rsplit_aux n (fst w) (snd w) []"
 
 fun bin_rsplitl_aux :: "nat \<Rightarrow> nat \<Rightarrow> int \<Rightarrow> int list \<Rightarrow> int list"
   where "bin_rsplitl_aux n m c bs =
     (if m = 0 \<or> n = 0 then bs
      else
       let (a, b) = bin_split (min m n) c
       in bin_rsplitl_aux n (m - n) a (b # bs))"
 
 definition bin_rsplitl :: "nat \<Rightarrow> nat \<times> int \<Rightarrow> int list"
   where "bin_rsplitl n w = bin_rsplitl_aux n (fst w) (snd w) []"
 
 declare bin_rsplit_aux.simps [simp del]
 declare bin_rsplitl_aux.simps [simp del]
 
 lemma bin_nth_cat:
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) ((\<lambda>k n l. concat_bit n l k) x k y) n =
     (if n < k then (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n else (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x (n - k))"
   by (simp add: bit_concat_bit_iff)
 
 lemma bin_nth_drop_bit_iff:
   \<open>(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (drop_bit n c) k \<longleftrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) c (n + k)\<close>
   by (simp add: bit_drop_bit_eq)
 
 lemma bin_nth_take_bit_iff:
   \<open>(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (take_bit n c) k \<longleftrightarrow> k < n \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) c k\<close>
   by (fact bit_take_bit_iff)
 
 lemma bin_nth_split:
   "bin_split n c = (a, b) \<Longrightarrow>
     (\<forall>k. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) a k = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) c (n + k)) \<and>
     (\<forall>k. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) b k = (k < n \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) c k))"
   by (auto simp add: bin_nth_drop_bit_iff bin_nth_take_bit_iff)
 
 lemma bin_cat_zero [simp]: "(\<lambda>k n l. concat_bit n l k) 0 n w = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: bin_cat_eq_push_bit_add_take_bit)
 
 lemma bintr_cat1: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (k + n) ((\<lambda>k n l. concat_bit n l k) a n b) = (\<lambda>k n l. concat_bit n l k) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) k a) n b"
   by (metis bin_cat_assoc bin_cat_zero)
 
 lemma bintr_cat: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m ((\<lambda>k n l. concat_bit n l k) a n b) =
     (\<lambda>k n l. concat_bit n l k) ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (m - n) a) n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (min m n) b)"
   by (rule bin_eqI) (auto simp: bin_nth_cat nth_bintr)
 
 lemma bintr_cat_same [simp]: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((\<lambda>k n l. concat_bit n l k) a n b) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n b"
   by (auto simp add : bintr_cat)
 
 lemma cat_bintr [simp]: "(\<lambda>k n l. concat_bit n l k) a n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n b) = (\<lambda>k n l. concat_bit n l k) a n b"
   by (simp add: bin_cat_eq_push_bit_add_take_bit)
 
 lemma split_bintrunc: "bin_split n c = (a, b) \<Longrightarrow> b = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n c"
   by simp
 
 lemma bin_cat_split: "bin_split n w = (u, v) \<Longrightarrow> w = (\<lambda>k n l. concat_bit n l k) u n v"
   by (auto simp add: bin_cat_eq_push_bit_add_take_bit bits_ident)
 
 lemma drop_bit_bin_cat_eq:
   \<open>drop_bit n ((\<lambda>k n l. concat_bit n l k) v n w) = v\<close>
   by (rule bit_eqI) (simp add: bit_drop_bit_eq bit_concat_bit_iff)
 
 lemma take_bit_bin_cat_eq:
   \<open>take_bit n ((\<lambda>k n l. concat_bit n l k) v n w) = take_bit n w\<close>
   by (rule bit_eqI) (simp add: bit_concat_bit_iff)
 
 lemma bin_split_cat: "bin_split n ((\<lambda>k n l. concat_bit n l k) v n w) = (v, (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w)"
   by (simp add: drop_bit_bin_cat_eq take_bit_bin_cat_eq)
 
 lemma bin_split_zero [simp]: "bin_split n 0 = (0, 0)"
   by simp
 
 lemma bin_split_minus1 [simp]:
   "bin_split n (- 1) = (- 1, (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (- 1))"
   by simp
 
 lemma bin_split_trunc:
   "bin_split (min m n) c = (a, b) \<Longrightarrow>
     bin_split n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m c) = ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (m - n) a, b)"
   apply (induct n arbitrary: m b c, clarsimp)
   apply (simp add: bin_rest_trunc Let_def split: prod.split_asm)
   apply (case_tac m)
    apply (auto simp: Let_def drop_bit_Suc take_bit_Suc mod_2_eq_odd split: prod.split_asm)
   done
 
 lemma bin_split_trunc1:
   "bin_split n c = (a, b) \<Longrightarrow>
     bin_split n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m c) = ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (m - n) a, (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m b)"
   apply (induct n arbitrary: m b c, clarsimp)
   apply (simp add: bin_rest_trunc Let_def split: prod.split_asm)
   apply (case_tac m)
    apply (auto simp: Let_def drop_bit_Suc take_bit_Suc mod_2_eq_odd split: prod.split_asm)
   done
 
 lemma bin_cat_num: "(\<lambda>k n l. concat_bit n l k) a n b = a * 2 ^ n + (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n b"
   by (simp add: bin_cat_eq_push_bit_add_take_bit push_bit_eq_mult)
 
 lemma bin_split_num: "bin_split n b = (b div 2 ^ n, b mod 2 ^ n)"
   by (simp add: drop_bit_eq_div take_bit_eq_mod)
 
 lemmas bin_rsplit_aux_simps = bin_rsplit_aux.simps bin_rsplitl_aux.simps
 lemmas rsplit_aux_simps = bin_rsplit_aux_simps
 
 lemmas th_if_simp1 = if_split [where P = "(=) l", THEN iffD1, THEN conjunct1, THEN mp] for l
 lemmas th_if_simp2 = if_split [where P = "(=) l", THEN iffD1, THEN conjunct2, THEN mp] for l
 
 lemmas rsplit_aux_simp1s = rsplit_aux_simps [THEN th_if_simp1]
 
 lemmas rsplit_aux_simp2ls = rsplit_aux_simps [THEN th_if_simp2]
 \<comment> \<open>these safe to \<open>[simp add]\<close> as require calculating \<open>m - n\<close>\<close>
 lemmas bin_rsplit_aux_simp2s [simp] = rsplit_aux_simp2ls [unfolded Let_def]
 lemmas rbscl = bin_rsplit_aux_simp2s (2)
 
 lemmas rsplit_aux_0_simps [simp] =
   rsplit_aux_simp1s [OF disjI1] rsplit_aux_simp1s [OF disjI2]
 
 lemma bin_rsplit_aux_append: "bin_rsplit_aux n m c (bs @ cs) = bin_rsplit_aux n m c bs @ cs"
   apply (induct n m c bs rule: bin_rsplit_aux.induct)
   apply (subst bin_rsplit_aux.simps)
   apply (subst bin_rsplit_aux.simps)
   apply (clarsimp split: prod.split)
   done
 
 lemma bin_rsplitl_aux_append: "bin_rsplitl_aux n m c (bs @ cs) = bin_rsplitl_aux n m c bs @ cs"
   apply (induct n m c bs rule: bin_rsplitl_aux.induct)
   apply (subst bin_rsplitl_aux.simps)
   apply (subst bin_rsplitl_aux.simps)
   apply (clarsimp split: prod.split)
   done
 
 lemmas rsplit_aux_apps [where bs = "[]"] =
   bin_rsplit_aux_append bin_rsplitl_aux_append
 
 lemmas rsplit_def_auxs = bin_rsplit_def bin_rsplitl_def
 
 lemmas rsplit_aux_alts = rsplit_aux_apps
   [unfolded append_Nil rsplit_def_auxs [symmetric]]
 
 lemma bin_split_minus: "0 < n \<Longrightarrow> bin_split (Suc (n - 1)) w = bin_split n w"
   by auto
 
 lemma bin_split_pred_simp [simp]:
   "(0::nat) < numeral bin \<Longrightarrow>
     bin_split (numeral bin) w =
       (let (w1, w2) = bin_split (numeral bin - 1) ((\<lambda>k::int. k div 2) w)
        in (w1, of_bool (odd w) + 2 * w2))"
   by (simp add: take_bit_rec drop_bit_rec mod_2_eq_odd)
 
 lemma bin_rsplit_aux_simp_alt:
   "bin_rsplit_aux n m c bs =
     (if m = 0 \<or> n = 0 then bs
      else let (a, b) = bin_split n c in bin_rsplit n (m - n, a) @ b # bs)"
   apply (simp add: bin_rsplit_aux.simps [of n m c bs])
   apply (subst rsplit_aux_alts)
   apply (simp add: bin_rsplit_def)
   done
 
 lemmas bin_rsplit_simp_alt =
   trans [OF bin_rsplit_def bin_rsplit_aux_simp_alt]
 
 lemmas bthrs = bin_rsplit_simp_alt [THEN [2] trans]
 
 lemma bin_rsplit_size_sign' [rule_format]:
   "n > 0 \<Longrightarrow> rev sw = bin_rsplit n (nw, w) \<Longrightarrow> \<forall>v\<in>set sw. (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n v = v"
   apply (induct sw arbitrary: nw w)
    apply clarsimp
   apply clarsimp
   apply (drule bthrs)
   apply (simp (no_asm_use) add: Let_def split: prod.split_asm if_split_asm)
   apply clarify
   apply simp
   done
 
 lemmas bin_rsplit_size_sign = bin_rsplit_size_sign' [OF asm_rl
   rev_rev_ident [THEN trans] set_rev [THEN equalityD2 [THEN subsetD]]]
 
 lemma bin_nth_rsplit [rule_format] :
   "n > 0 \<Longrightarrow> m < n \<Longrightarrow>
     \<forall>w k nw.
       rev sw = bin_rsplit n (nw, w) \<longrightarrow>
       k < size sw \<longrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (sw ! k) m = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w (k * n + m)"
   apply (induct sw)
    apply clarsimp
   apply clarsimp
   apply (drule bthrs)
   apply (simp (no_asm_use) add: Let_def split: prod.split_asm if_split_asm)
   apply (erule allE, erule impE, erule exI)
   apply (case_tac k)
    apply clarsimp
    prefer 2
    apply clarsimp
    apply (erule allE)
    apply (erule (1) impE)
    apply (simp add: bit_drop_bit_eq ac_simps)
   apply (simp add: bit_take_bit_iff ac_simps)
   done
 
 lemma bin_rsplit_all: "0 < nw \<Longrightarrow> nw \<le> n \<Longrightarrow> bin_rsplit n (nw, w) = [(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w]"
   by (auto simp: bin_rsplit_def rsplit_aux_simp2ls split: prod.split dest!: split_bintrunc)
 
 lemma bin_rsplit_l [rule_format]:
   "\<forall>bin. bin_rsplitl n (m, bin) = bin_rsplit n (m, (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m bin)"
   apply (rule_tac a = "m" in wf_less_than [THEN wf_induct])
   apply (simp (no_asm) add: bin_rsplitl_def bin_rsplit_def)
   apply (rule allI)
   apply (subst bin_rsplitl_aux.simps)
   apply (subst bin_rsplit_aux.simps)
   apply (clarsimp simp: Let_def split: prod.split)
   apply (simp add: ac_simps)
   apply (subst rsplit_aux_alts(1))
   apply (subst rsplit_aux_alts(2))
   apply clarsimp
   unfolding bin_rsplit_def bin_rsplitl_def
   apply (simp add: drop_bit_take_bit)
   apply (case_tac \<open>x < n\<close>)
   apply (simp_all add: not_less min_def)
   done
 
 lemma bin_rsplit_rcat [rule_format]:
   "n > 0 \<longrightarrow> bin_rsplit n (n * size ws, bin_rcat n ws) = map ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n) ws"
   apply (unfold bin_rsplit_def bin_rcat_eq_foldl)
   apply (rule_tac xs = ws in rev_induct)
    apply clarsimp
   apply clarsimp
   apply (subst rsplit_aux_alts)
   apply (simp add: drop_bit_bin_cat_eq take_bit_bin_cat_eq)
   done
 
 lemma bin_rsplit_aux_len_le [rule_format] :
   "\<forall>ws m. n \<noteq> 0 \<longrightarrow> ws = bin_rsplit_aux n nw w bs \<longrightarrow>
     length ws \<le> m \<longleftrightarrow> nw + length bs * n \<le> m * n"
 proof -
   have *: R
     if d: "i \<le> j \<or> m < j'"
     and R1: "i * k \<le> j * k \<Longrightarrow> R"
     and R2: "Suc m * k' \<le> j' * k' \<Longrightarrow> R"
     for i j j' k k' m :: nat and R
     using d
     apply safe
     apply (rule R1, erule mult_le_mono1)
     apply (rule R2, erule Suc_le_eq [THEN iffD2 [THEN mult_le_mono1]])
     done
   have **: "0 < sc \<Longrightarrow> sc - n + (n + lb * n) \<le> m * n \<longleftrightarrow> sc + lb * n \<le> m * n"
     for sc m n lb :: nat
     apply safe
      apply arith
     apply (case_tac "sc \<ge> n")
      apply arith
     apply (insert linorder_le_less_linear [of m lb])
     apply (erule_tac k=n and k'=n in *)
      apply arith
     apply simp
     done
   show ?thesis
     apply (induct n nw w bs rule: bin_rsplit_aux.induct)
     apply (subst bin_rsplit_aux.simps)
     apply (simp add: ** Let_def split: prod.split)
     done
 qed
 
 lemma bin_rsplit_len_le: "n \<noteq> 0 \<longrightarrow> ws = bin_rsplit n (nw, w) \<longrightarrow> length ws \<le> m \<longleftrightarrow> nw \<le> m * n"
   by (auto simp: bin_rsplit_def bin_rsplit_aux_len_le)
 
 lemma bin_rsplit_aux_len:
   "n \<noteq> 0 \<Longrightarrow> length (bin_rsplit_aux n nw w cs) = (nw + n - 1) div n + length cs"
   apply (induct n nw w cs rule: bin_rsplit_aux.induct)
   apply (subst bin_rsplit_aux.simps)
   apply (clarsimp simp: Let_def split: prod.split)
   apply (erule thin_rl)
   apply (case_tac m)
    apply simp
   apply (case_tac "m \<le> n")
    apply (auto simp add: div_add_self2)
   done
 
 lemma bin_rsplit_len: "n \<noteq> 0 \<Longrightarrow> length (bin_rsplit n (nw, w)) = (nw + n - 1) div n"
   by (auto simp: bin_rsplit_def bin_rsplit_aux_len)
 
 lemma bin_rsplit_aux_len_indep:
   "n \<noteq> 0 \<Longrightarrow> length bs = length cs \<Longrightarrow>
     length (bin_rsplit_aux n nw v bs) =
     length (bin_rsplit_aux n nw w cs)"
 proof (induct n nw w cs arbitrary: v bs rule: bin_rsplit_aux.induct)
   case (1 n m w cs v bs)
   show ?case
   proof (cases "m = 0")
     case True
     with \<open>length bs = length cs\<close> show ?thesis by simp
   next
     case False
     from "1.hyps" [of \<open>bin_split n w\<close> \<open>drop_bit n w\<close> \<open>take_bit n w\<close>] \<open>m \<noteq> 0\<close> \<open>n \<noteq> 0\<close>
     have hyp: "\<And>v bs. length bs = Suc (length cs) \<Longrightarrow>
       length (bin_rsplit_aux n (m - n) v bs) =
       length (bin_rsplit_aux n (m - n) (drop_bit n w) (take_bit n w # cs))"
       using bin_rsplit_aux_len by fastforce
     from \<open>length bs = length cs\<close> \<open>n \<noteq> 0\<close> show ?thesis
       by (auto simp add: bin_rsplit_aux_simp_alt Let_def bin_rsplit_len split: prod.split)
   qed
 qed
 
 lemma bin_rsplit_len_indep:
   "n \<noteq> 0 \<Longrightarrow> length (bin_rsplit n (nw, v)) = length (bin_rsplit n (nw, w))"
   apply (unfold bin_rsplit_def)
   apply (simp (no_asm))
   apply (erule bin_rsplit_aux_len_indep)
   apply (rule refl)
   done
 
 
 subsection \<open>Logical operations\<close>
 
 primrec bin_sc :: "nat \<Rightarrow> bool \<Rightarrow> int \<Rightarrow> int"
   where
     Z: "bin_sc 0 b w = of_bool b + 2 * (\<lambda>k::int. k div 2) w"
   | Suc: "bin_sc (Suc n) b w = of_bool (odd w) + 2 * bin_sc n b (w div 2)"
 
 lemma bin_nth_sc [simp]: "bit (bin_sc n b w) n \<longleftrightarrow> b"
   by (induction n arbitrary: w) (simp_all add: bit_Suc)
 
 lemma bin_sc_sc_same [simp]: "bin_sc n c (bin_sc n b w) = bin_sc n c w"
   by (induction n arbitrary: w) (simp_all add: bit_Suc)
 
 lemma bin_sc_sc_diff: "m \<noteq> n \<Longrightarrow> bin_sc m c (bin_sc n b w) = bin_sc n b (bin_sc m c w)"
   apply (induct n arbitrary: w m)
    apply (case_tac [!] m)
      apply auto
   done
 
 lemma bin_nth_sc_gen: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (bin_sc n b w) m = (if m = n then b else (bit :: int \<Rightarrow> nat \<Rightarrow> bool) w m)"
   apply (induct n arbitrary: w m)
    apply (case_tac m; simp add: bit_Suc)
   apply (case_tac m; simp add: bit_Suc)
   done
 
 lemma bin_sc_eq:
   \<open>bin_sc n False = unset_bit n\<close>
   \<open>bin_sc n True = Bit_Operations.set_bit n\<close>
   by (simp_all add: fun_eq_iff bit_eq_iff)
     (simp_all add: bin_nth_sc_gen bit_set_bit_iff bit_unset_bit_iff)
 
 lemma bin_sc_nth [simp]: "bin_sc n ((bit :: int \<Rightarrow> nat \<Rightarrow> bool) w n) w = w"
   by (rule bit_eqI) (simp add: bin_nth_sc_gen)
 
 lemma bin_sign_sc [simp]: "bin_sign (bin_sc n b w) = bin_sign w"
 proof (induction n arbitrary: w)
   case 0
   then show ?case
     by (auto simp add: bin_sign_def) (use bin_rest_ge_0 in fastforce)
 next
   case (Suc n)
   from Suc [of \<open>w div 2\<close>]
   show ?case by (auto simp add: bin_sign_def split: if_splits)
 qed
 
 lemma bin_sc_bintr [simp]:
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m (bin_sc n x ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m w)) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) m (bin_sc n x w)"
   apply (cases x)
    apply (simp_all add: bin_sc_eq bit_eq_iff)
    apply (auto simp add: bit_take_bit_iff bit_set_bit_iff bit_unset_bit_iff)
   done
 
 lemma bin_clr_le: "bin_sc n False w \<le> w"
   by (simp add: bin_sc_eq unset_bit_less_eq)
 
 lemma bin_set_ge: "bin_sc n True w \<ge> w"
   by (simp add: bin_sc_eq set_bit_greater_eq)
 
 lemma bintr_bin_clr_le: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (bin_sc m False w) \<le> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: bin_sc_eq take_bit_unset_bit_eq unset_bit_less_eq)
 
 lemma bintr_bin_set_ge: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (bin_sc m True w) \<ge> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n w"
   by (simp add: bin_sc_eq take_bit_set_bit_eq set_bit_greater_eq)
 
 lemma bin_sc_FP [simp]: "bin_sc n False 0 = 0"
   by (induct n) auto
 
 lemma bin_sc_TM [simp]: "bin_sc n True (- 1) = - 1"
   by (induct n) auto
 
 lemmas bin_sc_simps = bin_sc.Z bin_sc.Suc bin_sc_TM bin_sc_FP
 
 lemma bin_sc_minus: "0 < n \<Longrightarrow> bin_sc (Suc (n - 1)) b w = bin_sc n b w"
   by auto
 
 lemmas bin_sc_Suc_minus =
   trans [OF bin_sc_minus [symmetric] bin_sc.Suc]
 
 lemma bin_sc_numeral [simp]:
   "bin_sc (numeral k) b w =
     of_bool (odd w) + 2 * bin_sc (pred_numeral k) b (w div 2)"
   by (simp add: numeral_eq_Suc)
 
 lemmas bin_sc_minus_simps =
   bin_sc_simps (2,3,4) [THEN [2] trans, OF bin_sc_minus [THEN sym]]
 
 instance int :: semiring_bit_syntax ..
 
 lemma shiftl_int_def:
   "shiftl x n = x * 2 ^ n" for x :: int
   by (simp add: push_bit_int_def shiftl_eq_push_bit)
 
 lemma shiftr_int_def:
   "shiftr x n = x div 2 ^ n" for x :: int
   by (simp add: drop_bit_int_def shiftr_eq_drop_bit)
 
 
 subsubsection \<open>Basic simplification rules\<close>
 
 lemmas int_not_def = not_int_def
 
 lemma int_not_simps [simp]:
   "NOT (0::int) = -1"
   "NOT (1::int) = -2"
   "NOT (- 1::int) = 0"
   "NOT (numeral w::int) = - numeral (w + Num.One)"
   "NOT (- numeral (Num.Bit0 w)::int) = numeral (Num.BitM w)"
   "NOT (- numeral (Num.Bit1 w)::int) = numeral (Num.Bit0 w)"
   by (simp_all add: not_int_def)
 
 lemma int_not_not: "NOT (NOT x) = x"
   for x :: int
   by (fact bit.double_compl)
 
 lemma int_and_0 [simp]: "0 AND x = 0"
   for x :: int
   by (fact bit.conj_zero_left)
 
 lemma int_and_m1 [simp]: "-1 AND x = x"
   for x :: int
   by (fact bit.conj_one_left)
 
 lemma int_or_zero [simp]: "0 OR x = x"
   for x :: int
   by (fact bit.disj_zero_left)
 
 lemma int_or_minus1 [simp]: "-1 OR x = -1"
   for x :: int
   by (fact bit.disj_one_left)
 
 lemma int_xor_zero [simp]: "0 XOR x = x"
   for x :: int
   by (fact bit.xor_zero_left)
 
 
 subsubsection \<open>Binary destructors\<close>
 
 lemma bin_rest_NOT [simp]: "(\<lambda>k::int. k div 2) (NOT x) = NOT ((\<lambda>k::int. k div 2) x)"
   by (fact not_int_div_2)
 
 lemma bin_last_NOT [simp]: "(odd :: int \<Rightarrow> bool) (NOT x) \<longleftrightarrow> \<not> (odd :: int \<Rightarrow> bool) x"
   by simp
 
 lemma bin_rest_AND [simp]: "(\<lambda>k::int. k div 2) (x AND y) = (\<lambda>k::int. k div 2) x AND (\<lambda>k::int. k div 2) y"
   by (subst and_int_rec) auto
 
 lemma bin_last_AND [simp]: "(odd :: int \<Rightarrow> bool) (x AND y) \<longleftrightarrow> (odd :: int \<Rightarrow> bool) x \<and> (odd :: int \<Rightarrow> bool) y"
   by (subst and_int_rec) auto
 
 lemma bin_rest_OR [simp]: "(\<lambda>k::int. k div 2) (x OR y) = (\<lambda>k::int. k div 2) x OR (\<lambda>k::int. k div 2) y"
   by (subst or_int_rec) auto
 
 lemma bin_last_OR [simp]: "(odd :: int \<Rightarrow> bool) (x OR y) \<longleftrightarrow> (odd :: int \<Rightarrow> bool) x \<or> (odd :: int \<Rightarrow> bool) y"
   by (subst or_int_rec) auto
 
 lemma bin_rest_XOR [simp]: "(\<lambda>k::int. k div 2) (x XOR y) = (\<lambda>k::int. k div 2) x XOR (\<lambda>k::int. k div 2) y"
   by (subst xor_int_rec) auto
 
 lemma bin_last_XOR [simp]: "(odd :: int \<Rightarrow> bool) (x XOR y) \<longleftrightarrow> ((odd :: int \<Rightarrow> bool) x \<or> (odd :: int \<Rightarrow> bool) y) \<and> \<not> ((odd :: int \<Rightarrow> bool) x \<and> (odd :: int \<Rightarrow> bool) y)"
   by (subst xor_int_rec) auto
 
 lemma bin_nth_ops:
   "\<And>x y. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x AND y) n \<longleftrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n"
   "\<And>x y. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x OR y) n \<longleftrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n \<or> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n"
   "\<And>x y. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x XOR y) n \<longleftrightarrow> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n \<noteq> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) y n"
   "\<And>x. (bit :: int \<Rightarrow> nat \<Rightarrow> bool) (NOT x) n \<longleftrightarrow> \<not> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n"
   by (simp_all add: bit_and_iff bit_or_iff bit_xor_iff bit_not_iff)
 
 
 subsubsection \<open>Derived properties\<close>
 
 lemma int_xor_minus1 [simp]: "-1 XOR x = NOT x"
   for x :: int
   by (fact bit.xor_one_left)
 
 lemma int_xor_extra_simps [simp]:
   "w XOR 0 = w"
   "w XOR -1 = NOT w"
   for w :: int
   by simp_all
 
 lemma int_or_extra_simps [simp]:
   "w OR 0 = w"
   "w OR -1 = -1"
   for w :: int
   by simp_all
 
 lemma int_and_extra_simps [simp]:
   "w AND 0 = 0"
   "w AND -1 = w"
   for w :: int
   by simp_all
 
 text \<open>Commutativity of the above.\<close>
 lemma bin_ops_comm:
   fixes x y :: int
   shows int_and_comm: "x AND y = y AND x"
     and int_or_comm:  "x OR y = y OR x"
     and int_xor_comm: "x XOR y = y XOR x"
   by (simp_all add: ac_simps)
 
 lemma bin_ops_same [simp]:
   "x AND x = x"
   "x OR x = x"
   "x XOR x = 0"
   for x :: int
   by simp_all
 
 lemmas bin_log_esimps =
   int_and_extra_simps  int_or_extra_simps  int_xor_extra_simps
   int_and_0 int_and_m1 int_or_zero int_or_minus1 int_xor_zero int_xor_minus1
 
 
 subsubsection \<open>Basic properties of logical (bit-wise) operations\<close>
 
 lemma bbw_ao_absorb: "x AND (y OR x) = x \<and> x OR (y AND x) = x"
   for x y :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma bbw_ao_absorbs_other:
   "x AND (x OR y) = x \<and> (y AND x) OR x = x"
   "(y OR x) AND x = x \<and> x OR (x AND y) = x"
   "(x OR y) AND x = x \<and> (x AND y) OR x = x"
   for x y :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemmas bbw_ao_absorbs [simp] = bbw_ao_absorb bbw_ao_absorbs_other
 
 lemma int_xor_not: "(NOT x) XOR y = NOT (x XOR y) \<and> x XOR (NOT y) = NOT (x XOR y)"
   for x y :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma int_and_assoc: "(x AND y) AND z = x AND (y AND z)"
   for x y z :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma int_or_assoc: "(x OR y) OR z = x OR (y OR z)"
   for x y z :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma int_xor_assoc: "(x XOR y) XOR z = x XOR (y XOR z)"
   for x y z :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemmas bbw_assocs = int_and_assoc int_or_assoc int_xor_assoc
 
 (* BH: Why are these declared as simp rules??? *)
 lemma bbw_lcs [simp]:
   "y AND (x AND z) = x AND (y AND z)"
   "y OR (x OR z) = x OR (y OR z)"
   "y XOR (x XOR z) = x XOR (y XOR z)"
   for x y :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma bbw_not_dist:
   "NOT (x OR y) = (NOT x) AND (NOT y)"
   "NOT (x AND y) = (NOT x) OR (NOT y)"
   for x y :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma bbw_oa_dist: "(x AND y) OR z = (x OR z) AND (y OR z)"
   for x y z :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 lemma bbw_ao_dist: "(x OR y) AND z = (x AND z) OR (y AND z)"
   for x y z :: int
   by (auto simp add: bin_eq_iff bin_nth_ops)
 
 (*
 Why were these declared simp???
 declare bin_ops_comm [simp] bbw_assocs [simp]
 *)
 
 
 subsubsection \<open>Simplification with numerals\<close>
 
 text \<open>Cases for \<open>0\<close> and \<open>-1\<close> are already covered by other simp rules.\<close>
 
 lemma bin_rest_neg_numeral_BitM [simp]:
   "(\<lambda>k::int. k div 2) (- numeral (Num.BitM w)) = - numeral w"
   by simp
 
 lemma bin_last_neg_numeral_BitM [simp]:
   "(odd :: int \<Rightarrow> bool) (- numeral (Num.BitM w))"
   by simp
 
 
 subsubsection \<open>Interactions with arithmetic\<close>
 
 lemma le_int_or: "bin_sign y = 0 \<Longrightarrow> x \<le> x OR y"
   for x y :: int
   by (simp add: bin_sign_def or_greater_eq split: if_splits)
 
 lemmas int_and_le =
   xtrans(3) [OF bbw_ao_absorbs (2) [THEN conjunct2, symmetric] le_int_or]
 
 text \<open>Interaction between bit-wise and arithmetic: good example of \<open>bin_induction\<close>.\<close>
 lemma bin_add_not: "x + NOT x = (-1::int)"
   by (simp add: not_int_def)
 
 lemma AND_mod: "x AND (2 ^ n - 1) = x mod 2 ^ n"
   for x :: int
   by (simp flip: take_bit_eq_mod add: take_bit_eq_mask mask_eq_exp_minus_1)
 
 
 subsubsection \<open>Truncating results of bit-wise operations\<close>
 
 lemma bin_trunc_ao:
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x AND (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (x AND y)"
   "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x OR (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (x OR y)"
   by simp_all
 
 lemma bin_trunc_xor: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x XOR (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (x XOR y)"
   by simp
 
 lemma bin_trunc_not: "(take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (NOT ((take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x)) = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n (NOT x)"
   by (fact take_bit_not_take_bit)
 
 text \<open>Want theorems of the form of \<open>bin_trunc_xor\<close>.\<close>
 lemma bintr_bintr_i: "x = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y \<Longrightarrow> (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x = (take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n y"
   by auto
 
 lemmas bin_trunc_and = bin_trunc_ao(1) [THEN bintr_bintr_i]
 lemmas bin_trunc_or = bin_trunc_ao(2) [THEN bintr_bintr_i]
 
 
 subsubsection \<open>More lemmas\<close>
 
 lemma not_int_cmp_0 [simp]:
   fixes i :: int shows
   "0 < NOT i \<longleftrightarrow> i < -1"
   "0 \<le> NOT i \<longleftrightarrow> i < 0"
   "NOT i < 0 \<longleftrightarrow> i \<ge> 0"
   "NOT i \<le> 0 \<longleftrightarrow> i \<ge> -1"
 by(simp_all add: int_not_def) arith+
 
 lemma bbw_ao_dist2: "(x :: int) AND (y OR z) = x AND y OR x AND z"
   by (fact bit.conj_disj_distrib)
 
 lemmas int_and_ac = bbw_lcs(1) int_and_comm int_and_assoc
 
 lemma int_nand_same [simp]: fixes x :: int shows "x AND NOT x = 0"
   by simp
 
 lemma int_nand_same_middle: fixes x :: int shows "x AND y AND NOT x = 0"
   by (simp add: bit_eq_iff bit_and_iff bit_not_iff)
 
 lemma and_xor_dist: fixes x :: int shows
   "x AND (y XOR z) = (x AND y) XOR (x AND z)"
   by (fact bit.conj_xor_distrib)
 
 lemma int_and_lt0 [simp]:
   \<open>x AND y < 0 \<longleftrightarrow> x < 0 \<and> y < 0\<close> for x y :: int
   by (fact and_negative_int_iff)
 
 lemma int_and_ge0 [simp]:
   \<open>x AND y \<ge> 0 \<longleftrightarrow> x \<ge> 0 \<or> y \<ge> 0\<close> for x y :: int
   by (fact and_nonnegative_int_iff)
 
 lemma int_and_1: fixes x :: int shows "x AND 1 = x mod 2"
   by (fact and_one_eq)
 
 lemma int_1_and: fixes x :: int shows "1 AND x = x mod 2"
   by (fact one_and_eq)
 
 lemma int_or_lt0 [simp]:
   \<open>x OR y < 0 \<longleftrightarrow> x < 0 \<or> y < 0\<close> for x y :: int
   by (fact or_negative_int_iff)
 
 lemma int_or_ge0 [simp]:
   \<open>x OR y \<ge> 0 \<longleftrightarrow> x \<ge> 0 \<and> y \<ge> 0\<close> for x y :: int
   by (fact or_nonnegative_int_iff)
 
 lemma int_xor_lt0 [simp]:
   \<open>x XOR y < 0 \<longleftrightarrow> (x < 0) \<noteq> (y < 0)\<close> for x y :: int
   by (fact xor_negative_int_iff)
 
 lemma int_xor_ge0 [simp]:
   \<open>x XOR y \<ge> 0 \<longleftrightarrow> (x \<ge> 0 \<longleftrightarrow> y \<ge> 0)\<close> for x y :: int
   by (fact xor_nonnegative_int_iff)
 
 lemma even_conv_AND:
   \<open>even i \<longleftrightarrow> i AND 1 = 0\<close> for i :: int
   by (simp add: and_one_eq mod2_eq_if)
 
 lemma bin_last_conv_AND:
   "(odd :: int \<Rightarrow> bool) i \<longleftrightarrow> i AND 1 \<noteq> 0"
   by (simp add: and_one_eq mod2_eq_if)
 
 lemma bitval_bin_last:
   "of_bool ((odd :: int \<Rightarrow> bool) i) = i AND 1"
   by (simp add: and_one_eq mod2_eq_if)
 
 lemma bin_sign_and:
   "bin_sign (i AND j) = - (bin_sign i * bin_sign j)"
 by(simp add: bin_sign_def)
 
 lemma int_not_neg_numeral: "NOT (- numeral n) = (Num.sub n num.One :: int)"
 by(simp add: int_not_def)
 
 lemma int_neg_numeral_pOne_conv_not: "- numeral (n + num.One) = (NOT (numeral n) :: int)"
 by(simp add: int_not_def)
 
 
 subsection \<open>Setting and clearing bits\<close>
 
 lemma int_shiftl_BIT: fixes x :: int
   shows int_shiftl0 [simp]: "x << 0 = x"
   and int_shiftl_Suc [simp]: "x << Suc n = 2 * (x << n)"
   by (auto simp add: shiftl_int_def)
 
 lemma int_0_shiftl [simp]: "0 << n = (0 :: int)"
 by(induct n) simp_all
 
 lemma bin_last_shiftl: "(odd :: int \<Rightarrow> bool) (x << n) \<longleftrightarrow> n = 0 \<and> (odd :: int \<Rightarrow> bool) x"
 by(cases n)(simp_all)
 
 lemma bin_rest_shiftl: "(\<lambda>k::int. k div 2) (x << n) = (if n > 0 then x << (n - 1) else (\<lambda>k::int. k div 2) x)"
 by(cases n)(simp_all)
 
 lemma bin_nth_shiftl [simp]: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x << n) m \<longleftrightarrow> n \<le> m \<and> (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x (m - n)"
   by (simp add: bit_push_bit_iff_int shiftl_eq_push_bit)
 
 lemma bin_last_shiftr: "odd (x >> n) \<longleftrightarrow> bit x n" for x :: int
   by (simp add: shiftr_eq_drop_bit bit_iff_odd_drop_bit)
 
 lemma bin_rest_shiftr [simp]: "(\<lambda>k::int. k div 2) (x >> n) = x >> Suc n"
   by (simp add: bit_eq_iff shiftr_eq_drop_bit drop_bit_Suc bit_drop_bit_eq drop_bit_half)
 
 lemma bin_nth_shiftr [simp]: "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x >> n) m = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x (n + m)"
   by (simp add: shiftr_eq_drop_bit bit_drop_bit_eq)
 
 lemma bin_nth_conv_AND:
   fixes x :: int shows
   "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) x n \<longleftrightarrow> x AND (1 << n) \<noteq> 0"
   by (simp add: bit_eq_iff)
     (auto simp add: shiftl_eq_push_bit bit_and_iff bit_push_bit_iff bit_exp_iff)
 
 lemma int_shiftl_numeral [simp]:
   "(numeral w :: int) << numeral w' = numeral (num.Bit0 w) << pred_numeral w'"
   "(- numeral w :: int) << numeral w' = - numeral (num.Bit0 w) << pred_numeral w'"
 by(simp_all add: numeral_eq_Suc shiftl_int_def)
   (metis add_One mult_inc semiring_norm(11) semiring_norm(13) semiring_norm(2) semiring_norm(6) semiring_norm(87))+
 
 lemma int_shiftl_One_numeral [simp]:
   "(1 :: int) << numeral w = 2 << pred_numeral w"
   using int_shiftl_numeral [of Num.One w] by simp
 
 lemma shiftl_ge_0 [simp]: fixes i :: int shows "i << n \<ge> 0 \<longleftrightarrow> i \<ge> 0"
 by(induct n) simp_all
 
 lemma shiftl_lt_0 [simp]: fixes i :: int shows "i << n < 0 \<longleftrightarrow> i < 0"
 by (metis not_le shiftl_ge_0)
 
 lemma int_shiftl_test_bit: "bit (n << i :: int) m \<longleftrightarrow> m \<ge> i \<and> bit n (m - i)"
   by simp
 
 lemma int_0shiftr [simp]: "(0 :: int) >> x = 0"
 by(simp add: shiftr_int_def)
 
 lemma int_minus1_shiftr [simp]: "(-1 :: int) >> x = -1"
 by(simp add: shiftr_int_def div_eq_minus1)
 
 lemma int_shiftr_ge_0 [simp]: fixes i :: int shows "i >> n \<ge> 0 \<longleftrightarrow> i \<ge> 0"
   by (simp add: shiftr_eq_drop_bit)
 
 lemma int_shiftr_lt_0 [simp]: fixes i :: int shows "i >> n < 0 \<longleftrightarrow> i < 0"
 by (metis int_shiftr_ge_0 not_less)
 
 lemma int_shiftr_numeral [simp]:
   "(1 :: int) >> numeral w' = 0"
   "(numeral num.One :: int) >> numeral w' = 0"
   "(numeral (num.Bit0 w) :: int) >> numeral w' = numeral w >> pred_numeral w'"
   "(numeral (num.Bit1 w) :: int) >> numeral w' = numeral w >> pred_numeral w'"
   "(- numeral (num.Bit0 w) :: int) >> numeral w' = - numeral w >> pred_numeral w'"
   "(- numeral (num.Bit1 w) :: int) >> numeral w' = - numeral (Num.inc w) >> pred_numeral w'"
   by (simp_all add: shiftr_eq_drop_bit numeral_eq_Suc add_One drop_bit_Suc)
 
 lemma int_shiftr_numeral_Suc0 [simp]:
   "(1 :: int) >> Suc 0 = 0"
   "(numeral num.One :: int) >> Suc 0 = 0"
   "(numeral (num.Bit0 w) :: int) >> Suc 0 = numeral w"
   "(numeral (num.Bit1 w) :: int) >> Suc 0 = numeral w"
   "(- numeral (num.Bit0 w) :: int) >> Suc 0 = - numeral w"
   "(- numeral (num.Bit1 w) :: int) >> Suc 0 = - numeral (Num.inc w)"
   by (simp_all add: shiftr_eq_drop_bit drop_bit_Suc add_One)
 
 lemma bin_nth_minus_p2:
   assumes sign: "bin_sign x = 0"
   and y: "y = 1 << n"
   and m: "m < n"
   and x: "x < y"
   shows "(bit :: int \<Rightarrow> nat \<Rightarrow> bool) (x - y) m = (bit :: int \<Rightarrow> nat \<Rightarrow> bool) x m"
 proof -
   from sign y x have \<open>x \<ge> 0\<close> and \<open>y = 2 ^ n\<close> and \<open>x < 2 ^ n\<close>
     by (simp_all add: bin_sign_def shiftl_eq_push_bit push_bit_eq_mult split: if_splits)
   from \<open>0 \<le> x\<close> \<open>x < 2 ^ n\<close> \<open>m < n\<close> have \<open>bit x m \<longleftrightarrow> bit (x - 2 ^ n) m\<close>
   proof (induction m arbitrary: x n)
     case 0
     then show ?case
       by simp
   next
     case (Suc m)
     moreover define q where \<open>q = n - 1\<close>
     ultimately have n: \<open>n = Suc q\<close>
       by simp
     have \<open>(x - 2 ^ Suc q) div 2 = x div 2 - 2 ^ q\<close>
       by simp
     moreover from Suc.IH [of \<open>x div 2\<close> q] Suc.prems
     have \<open>bit (x div 2) m \<longleftrightarrow> bit (x div 2 - 2 ^ q) m\<close>
       by (simp add: n)
     ultimately show ?case
       by (simp add: bit_Suc n)
   qed
   with \<open>y = 2 ^ n\<close> show ?thesis
     by simp
 qed
 
 lemma bin_clr_conv_NAND:
   "bin_sc n False i = i AND NOT (1 << n)"
   by (induct n arbitrary: i) (rule bin_rl_eqI; simp)+
 
 lemma bin_set_conv_OR:
   "bin_sc n True i = i OR (1 << n)"
   by (induct n arbitrary: i) (rule bin_rl_eqI; simp)+
 
 
 subsection \<open>More lemmas on words\<close>
 
 lemma word_rcat_eq:
   \<open>word_rcat ws = word_of_int (bin_rcat (LENGTH('a::len)) (map uint ws))\<close>
   for ws :: \<open>'a::len word list\<close>
   apply (simp add: word_rcat_def bin_rcat_def rev_map)
   apply transfer
   apply (simp add: horner_sum_foldr foldr_map comp_def)
   done
 
 lemma sign_uint_Pls [simp]: "bin_sign (uint x) = 0"
   by (simp add: sign_Pls_ge_0)
 
 lemmas bin_log_bintrs = bin_trunc_not bin_trunc_xor bin_trunc_and bin_trunc_or
 
 \<comment> \<open>following definitions require both arithmetic and bit-wise word operations\<close>
 
 \<comment> \<open>to get \<open>word_no_log_defs\<close> from \<open>word_log_defs\<close>, using \<open>bin_log_bintrs\<close>\<close>
 lemmas wils1 = bin_log_bintrs [THEN word_of_int_eq_iff [THEN iffD2],
   folded uint_word_of_int_eq, THEN eq_reflection]
 
 \<comment> \<open>the binary operations only\<close>  (* BH: why is this needed? *)
 lemmas word_log_binary_defs =
   word_and_def word_or_def word_xor_def
 
-lemma setBit_no [simp]: "setBit (numeral bin) n = word_of_int (bin_sc n True (numeral bin))"
+lemma setBit_no: "set_bit n (numeral bin) = word_of_int (bin_sc n True (numeral bin))"
   by transfer (simp add: bin_sc_eq)
 
-lemma clearBit_no [simp]:
-  "clearBit (numeral bin) n = word_of_int (bin_sc n False (numeral bin))"
+lemma clearBit_no:
+  "unset_bit n (numeral bin) = word_of_int (bin_sc n False (numeral bin))"
   by transfer (simp add: bin_sc_eq)
 
 lemma eq_mod_iff: "0 < n \<Longrightarrow> b = b mod n \<longleftrightarrow> 0 \<le> b \<and> b < n"
   for b n :: int
   by auto (metis pos_mod_conj)+
 
 lemma split_uint_lem: "bin_split n (uint w) = (a, b) \<Longrightarrow>
     a = take_bit (LENGTH('a) - n) a \<and> b = take_bit (LENGTH('a)) b"
   for w :: "'a::len word"
   by transfer (simp add: drop_bit_take_bit ac_simps)
 
 \<comment> \<open>limited hom result\<close>
 lemma word_cat_hom:
   "LENGTH('a::len) \<le> LENGTH('b::len) + LENGTH('c::len) \<Longrightarrow>
     (word_cat (word_of_int w :: 'b word) (b :: 'c word) :: 'a word) =
     word_of_int ((\<lambda>k n l. concat_bit n l k) w (size b) (uint b))"
   by transfer (simp add: take_bit_concat_bit_eq)
 
 lemma bintrunc_shiftl:
   "take_bit n (m << i) = take_bit (n - i) m << i"
   for m :: int
   by (rule bit_eqI) (auto simp add: bit_take_bit_iff)
 
 lemma uint_shiftl:
   "uint (n << i) = take_bit (size n) (uint n << i)"
   by transfer (simp add: push_bit_take_bit shiftl_eq_push_bit)
 
 lemma bin_mask_conv_pow2:
   "mask n = 2 ^ n - (1 :: int)"
   by (fact mask_eq_exp_minus_1)
 
 lemma bin_mask_ge0: "mask n \<ge> (0 :: int)"
   by (fact mask_nonnegative_int)
 
 lemma and_bin_mask_conv_mod: "x AND mask n = x mod 2 ^ n"
   for x :: int
   by (simp flip: take_bit_eq_mod add: take_bit_eq_mask)
 
 lemma bin_mask_numeral:
   "mask (numeral n) = (1 :: int) + 2 * mask (pred_numeral n)"
   by (fact mask_numeral)
 
 lemma bin_nth_mask [simp]: "bit (mask n :: int) i \<longleftrightarrow> i < n"
   by (simp add: bit_mask_iff)
 
 lemma bin_sign_mask [simp]: "bin_sign (mask n) = 0"
   by (simp add: bin_sign_def bin_mask_conv_pow2)
 
 lemma bin_mask_p1_conv_shift: "mask n + 1 = (1 :: int) << n"
   by (simp add: bin_mask_conv_pow2 shiftl_int_def)
 
 lemma sbintrunc_eq_in_range:
   "((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x = x) = (x \<in> range ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n))"
   "(x = (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) n x) = (x \<in> range ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 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> (signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) 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 sint_range':
   \<open>- (2 ^ (LENGTH('a) - Suc 0)) \<le> sint x \<and> sint x < 2 ^ (LENGTH('a) - Suc 0)\<close>
   for x :: \<open>'a::len word\<close>
   apply transfer
   using sbintr_ge sbintr_lt apply auto
   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)
 
 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: "(signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (size a - 1) (sint a * sint b) \<in> range ((signed_take_bit :: nat \<Rightarrow> int \<Rightarrow> int) (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
 
 lemma bintrunc_id:
   "\<lbrakk>m \<le> int n; 0 < m\<rbrakk> \<Longrightarrow> take_bit n m = m"
   apply (simp add: take_bit_int_eq_self_iff)
   apply (metis n_less_equal_power_2 not_le of_nat_less_iff of_nat_numeral order_trans semiring_1_class.of_nat_power)
   done
 
 code_identifier
   code_module Bits_Int \<rightharpoonup>
   (SML) Bit_Operations and (OCaml) Bit_Operations and (Haskell) Bit_Operations and (Scala) Bit_Operations
 
 end
diff --git a/thys/Word_Lib/Guide.thy b/thys/Word_Lib/Guide.thy
--- a/thys/Word_Lib/Guide.thy
+++ b/thys/Word_Lib/Guide.thy
@@ -1,383 +1,389 @@
 (*
  * Copyright Florian Haftmann
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 (*<*)
 theory Guide
   imports Word_Lib_Sumo Word_64 Ancient_Numeral
 begin
 
 hide_const (open) Generic_set_bit.set_bit
 
 (*>*)
 section \<open>A short overview over bit operations and word types\<close>
 
 subsection \<open>Basic theories and key ideas\<close>
 
 text \<open>
   When formalizing bit operations, it is tempting to represent
   bit values as explicit lists over a binary type. This however
   is a bad idea, mainly due to the inherent ambiguities in
   representation concerning repeating leading bits.
 
   Hence this approach avoids such explicit lists altogether
   following an algebraic path:
 
     \<^item> Bit values are represented by numeric types: idealized
       unbounded bit values can be represented by type \<^typ>\<open>int\<close>,
       bounded bit values by quotient types over \<^typ>\<open>int\<close>, aka \<^typ>\<open>'a word\<close>.
 
     \<^item> (A special case are idealized unbounded bit values ending
       in @{term [source] 0} which can be represented by type \<^typ>\<open>nat\<close> but
       only support a restricted set of operations).
 
   The most fundamental ideas are developed in theory \<^theory>\<open>HOL.Parity\<close>
   (which is part of \<^theory>\<open>Main\<close>):
 
     \<^item> Multiplication by \<^term>\<open>2 :: int\<close> is a bit shift to the left and
 
     \<^item> Division by \<^term>\<open>2 :: int\<close> is a bit shift to the right.
 
     \<^item> Concerning bounded bit values, iterated shifts to the left
     may result in eliminating all bits by shifting them all
     beyond the boundary.  The property \<^prop>\<open>(2 :: int) ^ n \<noteq> 0\<close>
     represents that \<^term>\<open>n\<close> is \<^emph>\<open>not\<close> beyond that boundary.
 
     \<^item> The projection on a single bit is then @{thm [mode=iff] bit_iff_odd [where ?'a = int, no_vars]}.
 
     \<^item> This leads to the most fundamental properties of bit values:
 
       \<^item> Equality rule: @{thm [display, mode=iff] bit_eq_iff [where ?'a = int, no_vars]}
 
       \<^item> Induction rule: @{thm [display, mode=iff] bits_induct [where ?'a = int, no_vars]}
 
     \<^item> Characteristic properties \<^prop>\<open>bit (f x) n \<longleftrightarrow> P x n\<close>
       are available in fact collection \<^text>\<open>bit_simps\<close>.
 
   On top of this, the following generic operations are provided
   after import of theory \<^theory>\<open>HOL-Library.Bit_Operations\<close>:
 
     \<^item> Singleton \<^term>\<open>n\<close>th bit: \<^term>\<open>(2 :: int) ^ n\<close>
 
     \<^item> Bit mask upto bit \<^term>\<open>n\<close>: @{thm mask_eq_exp_minus_1 [where ?'a = int, no_vars]}
 
     \<^item> Left shift: @{thm push_bit_eq_mult [where ?'a = int, no_vars]}
 
     \<^item> Right shift: @{thm drop_bit_eq_div [where ?'a = int, no_vars]}
 
     \<^item> Truncation: @{thm take_bit_eq_mod [where ?'a = int, no_vars]}
 
     \<^item> Bitwise negation: @{thm [mode=iff] bit_not_iff [where ?'a = int, no_vars]}
 
     \<^item> Bitwise conjunction: @{thm [mode=iff] bit_and_iff [where ?'a = int, no_vars]}
 
     \<^item> Bitwise disjunction: @{thm [mode=iff] bit_or_iff [where ?'a = int, no_vars]}
 
     \<^item> Bitwise exclusive disjunction: @{thm [mode=iff] bit_xor_iff [where ?'a = int, no_vars]}
 
     \<^item> Setting a single bit: @{thm set_bit_def [where ?'a = int, no_vars]}
 
     \<^item> Unsetting a single bit: @{thm unset_bit_def [where ?'a = int, no_vars]}
 
     \<^item> Flipping a single bit: @{thm flip_bit_def [where ?'a = int, no_vars]}
 
     \<^item> Signed truncation, or modulus centered around \<^term>\<open>0::int\<close>:
         @{thm [display] signed_take_bit_def [where ?'a = int, no_vars]}
 
     \<^item> (Bounded) conversion from and to a list of bits:
         @{thm [display] horner_sum_bit_eq_take_bit [where ?'a = int, no_vars]}
 
   Bit concatenation on \<^typ>\<open>int\<close> as given by 
     @{thm [display] concat_bit_def [no_vars]}
   appears quite
   technical but is the logical foundation for the quite natural bit concatenation
   on \<^typ>\<open>'a word\<close> (see below).
   
   Proper word types are introduced in theory \<^theory>\<open>HOL-Library.Word\<close>, with
   the following specific operations:
 
     \<^item> Standard arithmetic:
         @{term \<open>(+) :: 'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>},
         @{term \<open>uminus :: 'a::len word \<Rightarrow> 'a word\<close>},
         @{term \<open>(-) :: 'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>},
         @{term \<open>(*) :: 'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>},
         @{term \<open>0 :: 'a::len word\<close>}, @{term \<open>1 :: 'a::len word\<close>}, numerals etc.
 
     \<^item> Standard bit operations: see above.
 
     \<^item> Conversion with unsigned interpretation of words:
 
         \<^item> @{term [source] \<open>unsigned :: 'a::len word \<Rightarrow> 'b::semiring_1\<close>}
 
         \<^item> Important special cases as abbreviations:
 
             \<^item> @{term [source] \<open>unat :: 'a::len word \<Rightarrow> nat\<close>}
 
             \<^item> @{term [source] \<open>uint :: 'a::len word \<Rightarrow> int\<close>}
 
             \<^item> @{term [source] \<open>ucast :: 'a::len word \<Rightarrow> 'b::len word\<close>}
 
     \<^item> Conversion with signed interpretation of words:
 
         \<^item> @{term [source] \<open>signed :: 'a::len word \<Rightarrow> 'b::ring_1\<close>}
 
         \<^item> Important special cases as abbreviations:
 
             \<^item> @{term [source] \<open>sint :: 'a::len word \<Rightarrow> int\<close>}
 
             \<^item> @{term [source] \<open>scast :: 'a::len word \<Rightarrow> 'b::len word\<close>}
 
     \<^item> Operations with unsigned interpretation of words:
 
         \<^item> @{thm [mode=iff] word_le_nat_alt [no_vars]}
 
         \<^item> @{thm [mode=iff] word_less_nat_alt [no_vars]}
 
         \<^item> @{thm unat_div_distrib [no_vars]}
 
         \<^item> @{thm unat_drop_bit_eq [no_vars]}
 
         \<^item> @{thm unat_mod_distrib [no_vars]}
 
         \<^item> @{thm [mode=iff] udvd_iff_dvd [no_vars]}
 
     \<^item> Operations with signed interpretation of words:
 
         \<^item> @{thm [mode=iff] word_sle_eq [no_vars]}
 
         \<^item> @{thm [mode=iff] word_sless_alt [no_vars]}
 
         \<^item> @{thm sint_signed_drop_bit_eq [no_vars]}
 
     \<^item> Rotation and reversal:
 
         \<^item> @{term [source] \<open>word_rotl :: nat \<Rightarrow> 'a::len word \<Rightarrow> 'a word\<close>}
 
         \<^item> @{term [source] \<open>word_rotr :: nat \<Rightarrow> 'a::len word \<Rightarrow> 'a word\<close>}
 
         \<^item> @{term [source] \<open>word_roti :: int \<Rightarrow> 'a::len word \<Rightarrow> 'a word\<close>}
 
         \<^item> @{term [source] \<open>word_reverse :: 'a::len word \<Rightarrow> 'a word\<close>}
 
     \<^item> Concatenation: @{term [source, display] \<open>word_cat :: 'a::len word \<Rightarrow> 'b::len word \<Rightarrow> 'c::len word\<close>}
 
   For proofs about words the following default strategies are applicable:
 
     \<^item> Using bit extensionality (facts \<^text>\<open>bit_eq_iff\<close>, \<^text>\<open>bit_eqI\<close>; fact
       collection \<^text>\<open>bit_simps\<close>).
 
     \<^item> Using the @{method transfer} method.
 \<close>
 
 subsection \<open>More library theories\<close>
 
 text \<open>
   Note: currently, the theories listed here are hardly separate
   entities since they import each other in various ways.
   Always inspect them to understand what you pull in if you
   want to import one.
 
     \<^descr>[Syntax]
 
       \<^descr>[\<^theory>\<open>Word_Lib.Syntax_Bundles\<close>]
         Bundles to provide alternative syntax for various bit operations
 
       \<^descr>[\<^theory>\<open>Word_Lib.Hex_Words\<close>]
         Printing word numerals as hexadecimal numerals.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Type_Syntax\<close>]
         Pretty type-sensitive syntax for cast operations.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_Syntax\<close>]
         Specific ASCII syntax for prominent bit operations on word.
 
     \<^descr>[Proof tools]
 
       \<^descr>[\<^theory>\<open>Word_Lib.Norm_Words\<close>]
         Rewriting word numerals to normal forms.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Bitwise\<close>]
         Method @{method word_bitwise} decomposes word equalities and inequalities into bit propositions.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_EqI\<close>]
         Method @{method word_eqI_solve} decomposes word equalities and inequalities into bit propositions.
 
     \<^descr>[Operations]
 
       \<^descr>[\<^theory>\<open>Word_Lib.Signed_Division_Word\<close>]
 
         Signed division on word:
 
           \<^item> @{term [source] \<open>(sdiv) :: 'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>}
 
           \<^item> @{term [source] \<open>(smod) :: 'a::len word \<Rightarrow> 'a word \<Rightarrow> 'a word\<close>}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Aligned\<close>] \
 
           \<^item> @{thm [mode=iff] is_aligned_iff_udvd [no_vars]}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Least_significant_bit\<close>]
 
         The least significant bit as an alias:
         @{thm [mode=iff] lsb_odd [where ?'a = int, no_vars]}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Most_significant_bit\<close>]
 
         The most significant bit:
 
           \<^item> @{thm [mode=iff] msb_int_def [of k]}
 
           \<^item> @{thm [mode=iff] word_msb_sint [no_vars]}
 
           \<^item> @{thm [mode=iff] msb_word_iff_sless_0 [no_vars]}
 
           \<^item> @{thm [mode=iff] msb_word_iff_bit [no_vars]}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Traditional_Infix_Syntax\<close>]
 
         Clones of existing operations decorated with
         traditional syntax:
 
           \<^item> @{thm shiftl_eq_push_bit [no_vars]}
 
           \<^item> @{thm shiftr_eq_drop_bit [no_vars]}
 
           \<^item> @{thm sshiftr_eq [no_vars]}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Next_and_Prev\<close>] \
 
           \<^item> @{thm word_next_unfold [no_vars]}
 
           \<^item> @{thm word_prev_unfold [no_vars]}
 
       \<^descr>[\<^theory>\<open>Word_Lib.Enumeration_Word\<close>]
 
         More on explicit enumeration of word types.
 
       \<^descr>[\<^theory>\<open>Word_Lib.More_Word_Operations\<close>]
 
         Even more operations on word.
 
     \<^descr>[Types]
 
       \<^descr>[\<^theory>\<open>Word_Lib.Signed_Words\<close>]
 
           Formal tagging of word types with a \<^text>\<open>signed\<close> marker.
 
     \<^descr>[Lemmas]
 
       \<^descr>[\<^theory>\<open>Word_Lib.More_Word\<close>]
 
           More lemmas on words.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_Lemmas\<close>]
 
           More lemmas on words, covering many other theories mentioned here.
 
     \<^descr>[Words of popular lengths].
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_8\<close>]
 
           for 8-bit words.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_16\<close>]
 
           for 16-bit words.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_32\<close>]
 
           for 32-bit words.
 
       \<^descr>[\<^theory>\<open>Word_Lib.Word_64\<close>]
 
           for 64-bit words. This theory is not part of \<^text>\<open>Word_Lib_Sumo\<close>, because it shadows
           names from \<^theory>\<open>Word_Lib.Word_32\<close>. They can be used together, but then require
           to use qualified names in applications.
 \<close>
 
 
 subsection \<open>More library sessions\<close>
 
 text \<open>
   \<^descr>[\<^text>\<open>Native_Word\<close>] Makes machine words and machine arithmetic available for code generation.
   It provides a common abstraction that hides the differences between the different target languages.
   The code generator maps these operations to the APIs of the target languages.
 \<close>
 
 subsection \<open>Legacy theories\<close>
 
 text \<open>
   The following theories contain material which has been
   factored out since it is not recommended to use it in
   new applications, mostly because matters can be expressed
   succinctly using already existing operations.
 
   This section gives some indication how to migrate away
   from those theories.  However theorem coverage may still
   be terse in some cases.
 
   \<^descr>[\<^theory>\<open>Word_Lib.Word_Lib_Sumo\<close>]
 
     An entry point importing any relevant theory in that session.  Intended
     for backward compatibility: start importing this theory when
     migrating applications to Isabelle2021, and later sort out
     what you really need. You may need to include
    \<^theory>\<open>Word_Lib.Word_64\<close> separately.
 
   \<^descr>[\<^theory>\<open>Word_Lib.Generic_set_bit\<close>]
 
     Kind of an alias: @{thm set_bit_eq [no_vars]}
 
   \<^descr>[\<^theory>\<open>Word_Lib.Typedef_Morphisms\<close>]
 
     A low-level extension to HOL typedef providing
     conversions along type morphisms.  The @{method transfer} method
     seems to be sufficient for most applications though.
 
   \<^descr>[\<^theory>\<open>Word_Lib.Bit_Comprehension\<close>]
 
     Comprehension syntax for bit values over predicates
     \<^typ>\<open>nat \<Rightarrow> bool\<close>.  For \<^typ>\<open>'a::len word\<close>, straightforward
     alternatives exist; difficult to handle for \<^typ>\<open>int\<close>.
 
   \<^descr>[\<^theory>\<open>Word_Lib.Reversed_Bit_Lists\<close>]
 
     Representation of bit values as explicit list in
     \<^emph>\<open>reversed\<close> order.
 
     This should rarely be necessary: the \<^const>\<open>bit\<close> projection
     should be sufficient in most cases.  In case explicit lists
     are needed, existing operations can be used:
 
     @{thm [display] horner_sum_bit_eq_take_bit [where ?'a = int, no_vars]}
 
   \<^descr>[\<^theory>\<open>Word_Lib.Many_More\<close>]
 
     Collection of operations and theorems which are kept for backward
     compatibility and not used in other theories in session \<^text>\<open>Word_Lib\<close>.
     They are used in applications of \<^text>\<open>Word_Lib\<close>, but should be migrated to there.
 \<close>
 
 section \<open>Changelog\<close>
 
 text \<open>
   \<^descr>[Changes since AFP 2021] ~
 
     \<^item> Theory \<^theory>\<open>Word_Lib.Ancient_Numeral\<close> is no part of \<^theory>\<open>Word_Lib.Word_Lib_Sumo\<close>
       any longer.
 
     \<^item> Abbreviation \<^abbrev>\<open>max_word\<close> moved from distribution into theory
       \<^theory>\<open>Word_Lib.Legacy_Aliases\<close>.
 
     \<^item> Abbreviations \<^abbrev>\<open>bin_nth\<close>, \<^abbrev>\<open>bin_last\<close>, \<^abbrev>\<open>bin_rest\<close>,
       \<^abbrev>\<open>bintrunc\<close>, \<^abbrev>\<open>sbintrunc\<close>, \<^abbrev>\<open>norm_sint\<close>,
       \<^abbrev>\<open>bin_cat\<close> moved into theory \<^theory>\<open>Word_Lib.Legacy_Aliases\<close>.
 
+    \<^item> Operations \<^abbrev>\<open>shiftl1\<close>, \<^abbrev>\<open>shiftr1\<close>, \<^abbrev>\<open>sshiftr1\<close>, \<^abbrev>\<open>bshiftr1\<close>,
+      \<^abbrev>\<open>setBit\<close>, \<^abbrev>\<open>clearBit\<close> moved from distribution into theory
+      \<^theory>\<open>Word_Lib.Legacy_Aliases\<close> and replaced by input abbreviations.
+
+    \<^item> Operation \<^const>\<open>test_bit\<close> replaced by input abbreviation \<^abbrev>\<open>test_bit\<close>.
+
     \<^item> Operation \<^const>\<open>complement\<close> replaced by input abbreviation \<^abbrev>\<open>complement\<close>.
 \<close>
 
 (*<*)
 end
 (*>*)
diff --git a/thys/Word_Lib/Legacy_Aliases.thy b/thys/Word_Lib/Legacy_Aliases.thy
--- a/thys/Word_Lib/Legacy_Aliases.thy
+++ b/thys/Word_Lib/Legacy_Aliases.thy
@@ -1,50 +1,206 @@
 (*
  * Copyright Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 section \<open>Legacy aliases\<close>
 
 theory Legacy_Aliases
   imports "HOL-Library.Word"
 begin
 
 abbreviation (input) test_bit :: \<open>'a::semiring_bits \<Rightarrow> nat \<Rightarrow> bool\<close>
   where \<open>test_bit \<equiv> bit\<close>
 
 abbreviation (input) bin_nth :: \<open>int \<Rightarrow> nat \<Rightarrow> bool\<close>
   where \<open>bin_nth \<equiv> bit\<close>
 
 abbreviation (input) bin_last :: \<open>int \<Rightarrow> bool\<close>
   where \<open>bin_last \<equiv> odd\<close>
 
 abbreviation (input) bin_rest :: \<open>int \<Rightarrow> int\<close>
   where \<open>bin_rest w \<equiv> w div 2\<close>
 
 abbreviation (input) bintrunc :: \<open>nat \<Rightarrow> int \<Rightarrow> int\<close>
   where \<open>bintrunc \<equiv> take_bit\<close>
 
 abbreviation (input) sbintrunc :: \<open>nat \<Rightarrow> int \<Rightarrow> int\<close>
   where \<open>sbintrunc \<equiv> signed_take_bit\<close>
 
 abbreviation (input) bin_cat :: \<open>int \<Rightarrow> nat \<Rightarrow> int \<Rightarrow> int\<close>
   where \<open>bin_cat k n l \<equiv> concat_bit n l k\<close>
 
 abbreviation (input) norm_sint :: \<open>nat \<Rightarrow> int \<Rightarrow> int\<close>
   where \<open>norm_sint n \<equiv> signed_take_bit (n - 1)\<close>
 
 abbreviation (input) max_word :: \<open>'a::len word\<close>
   where \<open>max_word \<equiv> - 1\<close>
 
 abbreviation (input) complement :: \<open>'a::len word \<Rightarrow> 'a word\<close>
   where \<open>complement \<equiv> not\<close>
 
 lemma complement_mask:
   "complement (2 ^ n - 1) = NOT (mask n)"
   unfolding mask_eq_decr_exp by simp
 
+abbreviation (input) shiftl1 :: \<open>'a::len word \<Rightarrow> 'a word\<close>
+  where \<open>shiftl1 \<equiv> (*) 2\<close>
+
+abbreviation (input)  shiftr1 :: \<open>'a::len word \<Rightarrow> 'a word\<close>
+  where \<open>shiftr1 w \<equiv> w div 2\<close>
+
+abbreviation (input) sshiftr1 :: \<open>'a::len word \<Rightarrow> 'a word\<close>
+  where \<open>sshiftr1 \<equiv> signed_drop_bit (Suc 0)\<close>
+
+abbreviation (input) bshiftr1 :: \<open>bool \<Rightarrow> 'a::len word \<Rightarrow> 'a word\<close>
+  where \<open>bshiftr1 b w \<equiv> w div 2 OR push_bit (LENGTH('a) - Suc 0) (of_bool b) \<close>
+
+lemma shiftr1_1: "shiftr1 (1::'a::len word) = 0"
+  by (fact bits_1_div_2)
+
+lemma sshiftr1_eq:
+  \<open>sshiftr1 w = word_of_int (sint w div 2)\<close>
+  by (rule bit_word_eqI) (auto simp add: bit_simps min_def simp flip: bit_Suc elim: le_SucE)
+
+lemma shiftl1_eq:
+  \<open>shiftl1 w = word_of_int (2 * uint w)\<close>
+  by (rule bit_word_eqI) (simp add: bit_simps)
+
+lemma bit_shiftl1_iff:
+  \<open>bit (shiftl1 w) n \<longleftrightarrow> 0 < n \<and> n < LENGTH('a) \<and> bit w (n - 1)\<close>
+  for w :: \<open>'a::len word\<close>
+  by (auto simp add: bit_simps)
+
+lemma bit_shiftr1_iff:
+  \<open>bit (shiftr1 w) n \<longleftrightarrow> bit w (Suc n)\<close>
+  by (simp add: bit_Suc)
+
+lemma shiftr1_eq:
+  \<open>shiftr1 w = word_of_int (uint w div 2)\<close>
+  by (rule bit_word_eqI) (simp add: bit_simps flip: bit_Suc)
+
+lemma shiftl1_rev:
+  "shiftl1 w = word_reverse (shiftr1 (word_reverse w))"
+  by (rule bit_word_eqI) (auto simp add: bit_simps Suc_diff_Suc simp flip: bit_Suc)
+
+lemma shiftl1_p:
+  "shiftl1 w = w + w"
+  for w :: "'a::len word"
+  by (fact mult_2)
+
+lemma shiftr1_bintr:
+  "(shiftr1 (numeral w) :: 'a::len word) =
+    word_of_int (take_bit LENGTH('a) (numeral w) div 2)"
+  by (rule bit_word_eqI) (simp add: bit_simps flip: bit_Suc)
+
+lemma sshiftr1_sbintr:
+  "(sshiftr1 (numeral w) :: 'a::len word) =
+    word_of_int (signed_take_bit (LENGTH('a) - 1) (numeral w) div 2)"
+  apply (cases \<open>LENGTH('a)\<close>)
+  apply simp_all
+  apply (rule bit_word_eqI)
+  apply (auto simp add: bit_simps min_def simp flip: bit_Suc elim: le_SucE)
+  done
+
+lemma shiftl1_wi:
+  "shiftl1 (word_of_int w) = word_of_int (2 * w)"
+  by transfer simp
+
+lemma shiftl1_numeral:
+  "shiftl1 (numeral w) = numeral (Num.Bit0 w)"
+  unfolding word_numeral_alt shiftl1_wi by simp
+
+lemma shiftl1_neg_numeral:
+  "shiftl1 (- numeral w) = - numeral (Num.Bit0 w)"
+  unfolding word_neg_numeral_alt shiftl1_wi by simp
+
+lemma shiftl1_0:
+  "shiftl1 0 = 0"
+  by (fact mult_zero_right)
+
+lemma shiftl1_def_u:
+  "shiftl1 w = word_of_int (2 * uint w)"
+  by (fact shiftl1_eq)
+
+lemma shiftl1_def_s:
+  "shiftl1 w = word_of_int (2 * sint w)"
+  by simp
+
+lemma shiftr1_0:
+  "shiftr1 0 = 0"
+  by (fact bits_div_0)
+
+lemma sshiftr1_0:
+  "sshiftr1 0 = 0"
+  by (fact signed_drop_bit_of_0)
+
+lemma sshiftr1_n1:
+  "sshiftr1 (- 1) = - 1"
+  by (fact signed_drop_bit_of_minus_1)
+
+lemma uint_shiftr1:
+  "uint (shiftr1 w) = uint w div 2"
+  by (rule bit_eqI) (simp add: bit_simps flip: bit_Suc)
+
+lemma shiftr1_div_2:
+  "uint (shiftr1 w) = uint w div 2"
+  by (fact uint_shiftr1)
+
+lemma sshiftr1_div_2:
+  "sint (sshiftr1 w) = sint w div 2"
+  by (rule bit_eqI) (auto simp add: bit_simps ac_simps min_def simp flip: bit_Suc elim: le_SucE)
+
+lemma bit_sshiftr1_iff:
+  \<open>bit (sshiftr1 w) n \<longleftrightarrow> bit w (if n = LENGTH('a) - 1 then LENGTH('a) - 1 else Suc n)\<close>
+    for w :: \<open>'a::len word\<close>
+  by (auto simp add: bit_simps)
+
+lemma bit_bshiftr1_iff:
+  \<open>bit (bshiftr1 b w) n \<longleftrightarrow> b \<and> n = LENGTH('a) - 1 \<or> bit w (Suc n)\<close>
+    for w :: \<open>'a::len word\<close>
+  by (auto simp add: bit_simps simp flip: bit_Suc)
+
+lemma nth_shiftl1:
+  "bit (shiftl1 w) n \<longleftrightarrow> n < size w \<and> n > 0 \<and> bit w (n - 1)"
+  by (auto simp add: word_size bit_simps)
+
+lemma nth_shiftr1:
+  "bit (shiftr1 w) n = bit w (Suc n)"
+  by (simp add: bit_Suc)
+
+lemma nth_sshiftr1: "bit (sshiftr1 w) n = (if n = size w - 1 then bit w n else bit w (Suc n))"
+  by (auto simp add: word_size bit_simps)
+
+lemma shiftl_power:
+  "(shiftl1 ^^ x) (y::'a::len word) = 2 ^ x * y"
+  by (induction x) simp_all
+
+lemma le_shiftr1:
+  \<open>shiftr1 u \<le> shiftr1 v\<close> if \<open>u \<le> v\<close>
+  using that by (simp add: word_le_nat_alt unat_div div_le_mono)
+
+lemma le_shiftr1':
+  "\<lbrakk> shiftr1 u \<le> shiftr1 v ; shiftr1 u \<noteq> shiftr1 v \<rbrakk> \<Longrightarrow> u \<le> v"
+  by (meson dual_order.antisym le_cases le_shiftr1)
+
+abbreviation (input) setBit :: \<open>'a::len word \<Rightarrow> nat \<Rightarrow> 'a word\<close>
+  where \<open>setBit w n \<equiv> set_bit n w\<close>
+
+abbreviation (input) clearBit :: \<open>'a::len word \<Rightarrow> nat \<Rightarrow> 'a word\<close>
+  where \<open>clearBit w n \<equiv> unset_bit n w\<close>
+
+lemma bit_setBit_iff:
+  \<open>bit (setBit w m) n \<longleftrightarrow> (m = n \<and> n < LENGTH('a) \<or> bit w n)\<close>
+  for w :: \<open>'a::len word\<close>
+  by (auto simp add: bit_simps)
+
+lemma bit_clearBit_iff:
+  \<open>bit (clearBit w m) n \<longleftrightarrow> m \<noteq> n \<and> bit w n\<close>
+  for w :: \<open>'a::len word\<close>
+  by (auto simp add: bit_simps)
+
 lemmas less_def = less_eq [symmetric]
 lemmas le_def = not_less [symmetric, where ?'a = nat]
 
 end
diff --git a/thys/Word_Lib/More_Word.thy b/thys/Word_Lib/More_Word.thy
--- a/thys/Word_Lib/More_Word.thy
+++ b/thys/Word_Lib/More_Word.thy
@@ -1,2203 +1,2168 @@
 (*
  * Copyright Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 section \<open>Lemmas on words\<close>
 
 theory More_Word
   imports
     "HOL-Library.Word"
     More_Arithmetic
     More_Divides
 begin
 
 lemma unat_power_lower [simp]:
   "unat ((2::'a::len word) ^ n) = 2 ^ n" if "n < LENGTH('a::len)"
   using that by transfer simp
 
 lemma unat_p2: "n < LENGTH('a :: len) \<Longrightarrow> unat (2 ^ n :: 'a word) = 2 ^ n"
   by (fact unat_power_lower)
 
 lemma word_div_lt_eq_0:
   "x < y \<Longrightarrow> x div y = 0" for x :: "'a :: len word"
   by transfer simp
 
 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 word_of_nat_eq_iff flip: nat_div_eq_Suc_0_iff)
   apply (simp flip: unat_div unsigned_take_bit_eq)
   done
 
-lemma shiftl_power:
-  "(shiftl1 ^^ x) (y::'a::len word) = 2 ^ x * y"
-  apply (induct x)
-   apply simp
-  apply (simp add: shiftl1_2t)
-  done
-
 lemma AND_twice [simp]:
   "(w AND m) AND m = w AND m"
   by (fact and.right_idem)
 
 lemma word_combine_masks:
   "w AND m = z \<Longrightarrow> w AND m' = z' \<Longrightarrow> w AND (m OR m') = (z OR z')"
   for w m m' z z' :: \<open>'a::len word\<close>
   by (simp add: bit.conj_disj_distrib)
 
 lemma p2_gt_0:
   "(0 < (2 ^ n :: 'a :: len word)) = (n < LENGTH('a))"
   by (simp add : word_gt_0 not_le)
 
 lemma uint_2p_alt:
   \<open>n < LENGTH('a::len) \<Longrightarrow> uint ((2::'a::len word) ^ n) = 2 ^ n\<close>
   using p2_gt_0 [of n, where ?'a = 'a] by (simp add: uint_2p)
 
 lemma p2_eq_0:
   \<open>(2::'a::len word) ^ n = 0 \<longleftrightarrow> LENGTH('a::len) \<le> n\<close>
   by (fact exp_eq_zero_iff)
 
 lemma p2len:
   \<open>(2 :: 'a word) ^ LENGTH('a::len) = 0\<close>
   by simp
 
 lemma neg_mask_is_div:
   "w AND NOT (mask n) = (w div 2^n) * 2^n"
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI)
     (auto simp add: bit_simps simp flip: push_bit_eq_mult drop_bit_eq_div)
 
 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 (rule neg_mask_is_div)
 
 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>
   by (rule bit_word_eqI)
     (auto simp add: bit_simps word_size simp flip: push_bit_eq_mult drop_bit_eq_div)
 
 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 (rule and_mask_arith)
 
 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 AND mask n \<le> 2 ^ n - 1"
   for w :: \<open>'a::len word\<close>
   by (simp add: mask_2pm1[symmetric] word_and_le1)
 
 lemma is_aligned_AND_less_0:
   "u AND mask n = 0 \<Longrightarrow> v < 2^n \<Longrightarrow> u AND v = 0"
   for u v :: \<open>'a::len word\<close>
   apply (drule less_mask_eq)
   apply (simp flip: take_bit_eq_mask)
   apply (simp add: bit_eq_iff)
   apply (auto simp add: bit_simps)
   done
 
-lemma le_shiftr1:
-  \<open>shiftr1 u \<le> shiftr1 v\<close> if \<open>u \<le> v\<close>
-using that proof transfer
-  fix k l :: int
-  assume \<open>take_bit LENGTH('a) k \<le> take_bit LENGTH('a) l\<close>
-  then have \<open>take_bit LENGTH('a) (drop_bit 1 (take_bit LENGTH('a) k))
-    \<le> take_bit LENGTH('a) (drop_bit 1 (take_bit LENGTH('a) l))\<close>
-    apply (simp add: take_bit_drop_bit min_def)
-    apply (simp add: drop_bit_eq_div)
-    done
-  then show \<open>take_bit LENGTH('a) (take_bit LENGTH('a) k div 2)
-    \<le> take_bit LENGTH('a) (take_bit LENGTH('a) l div 2)\<close>
-    by (simp add: drop_bit_eq_div)
-qed
-
 lemma and_mask_eq_iff_le_mask:
   \<open>w AND mask n = w \<longleftrightarrow> w \<le> mask n\<close>
   for w :: \<open>'a::len word\<close>
   apply (simp flip: take_bit_eq_mask)
   apply (cases \<open>n \<ge> LENGTH('a)\<close>; transfer)
    apply (simp_all add: not_le min_def)
    apply (simp_all add: mask_eq_exp_minus_1)
   apply auto
    apply (metis take_bit_int_less_exp)
   apply (metis min_def nat_less_le take_bit_int_eq_self_iff take_bit_take_bit)
   done
 
 lemma less_eq_mask_iff_take_bit_eq_self:
   \<open>w \<le> mask n \<longleftrightarrow> take_bit n w = w\<close>
   for w :: \<open>'a::len word\<close>
   by (simp add: and_mask_eq_iff_le_mask take_bit_eq_mask)
 
 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
 
 lemma gt0_iff_gem1:
   \<open>0 < x \<longleftrightarrow> x - 1 < x\<close>
   for x :: \<open>'a::len word\<close>
   by (metis add.right_neutral diff_add_cancel less_irrefl measure_unat unat_arith_simps(2) word_neq_0_conv word_sub_less_iff)
 
 lemma power_2_ge_iff:
   \<open>2 ^ n - (1 :: 'a::len word) < 2 ^ n \<longleftrightarrow> n < LENGTH('a)\<close>
   using gt0_iff_gem1 p2_gt_0 by blast
 
 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])
 
 lemma mask_lt_2pn:
   \<open>n < LENGTH('a) \<Longrightarrow> mask n < (2 :: 'a::len word) ^ n\<close>
   by (simp add: mask_eq_exp_minus_1 power_2_ge_iff)
 
 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 word_and_max_word:
   fixes a::"'a::len word"
   shows "x = - 1 \<Longrightarrow> a AND x = a"
   by simp
 
 lemma word_and_full_mask_simp:
   \<open>x AND 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 AND Bit_Operations.mask LENGTH('a)) n \<longleftrightarrow> bit x n\<close>
     by (simp add: bit_and_iff bit_mask_iff)
 qed
 
 lemma of_int_uint:
   "of_int (uint x) = x"
   by (fact word_of_int_uint)
 
 corollary word_plus_and_or_coroll:
   "x AND y = 0 \<Longrightarrow> x + y = x OR y"
   for x y :: \<open>'a::len word\<close>
   using word_plus_and_or[where x=x and y=y]
   by simp
 
 corollary word_plus_and_or_coroll2:
   "(x AND w) + (x AND NOT w) = x"
   for x w :: \<open>'a::len word\<close>
   apply (subst disjunctive_add)
    apply (simp add: bit_simps)
   apply (simp flip: bit.conj_disj_distrib)
   done
 
 lemma nat_mask_eq:
   \<open>nat (mask n) = mask n\<close>
   by (simp add: nat_eq_iff of_nat_mask_eq)
 
 lemma unat_mask_eq:
   \<open>unat (mask n :: 'a::len word) = mask (min LENGTH('a) n)\<close>
   by transfer (simp add: nat_mask_eq)
 
 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 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 transfer (simp add: min_def split: if_splits)
 
 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"
   apply transfer
   apply (cases \<open>LENGTH('c) = LENGTH('a)\<close>)
    apply (auto simp add: min_def)
   done
 
 lemma ucast_0_I:
   "x = 0 \<Longrightarrow> ucast x = 0"
   by simp
 
 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  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)
 
 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_eq_unatI:
   \<open>v = w\<close> if \<open>unat v = unat w\<close>
   using that by transfer (simp add: nat_eq_iff)
 
 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_eq_unatI)
   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 enum_word_nth_eq:
   \<open>(Enum.enum :: 'a::len word list) ! n = word_of_nat n\<close>
     if \<open>n < 2 ^ LENGTH('a)\<close>
     for n
   using that by (simp add: enum_word_def)
 
 lemma length_enum_word_eq:
   \<open>length (Enum.enum :: 'a::len word list) = 2 ^ LENGTH('a)\<close>
   by (simp add: enum_word_def)
 
 lemma unat_lt2p [iff]:
   \<open>unat x < 2 ^ LENGTH('a)\<close> for x :: \<open>'a::len word\<close>
   by transfer simp
 
 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 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 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 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_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_all
   done
 
 lemma word_sub_1_le:
   "x \<noteq> 0 \<Longrightarrow> x - 1 \<le> (x :: ('a :: len) word)"
   apply (subst no_ulen_sub)
   apply simp
   apply (cases "uint x = 0")
    apply (simp add: uint_0_iff)
   apply (insert uint_ge_0[where x=x])
   apply arith
   done
 
 lemma push_bit_word_eq_nonzero:
   \<open>push_bit n w \<noteq> 0\<close> if \<open>w < 2 ^ m\<close> \<open>m + n < LENGTH('a)\<close> \<open>w \<noteq> 0\<close>
     for w :: \<open>'a::len word\<close>
   using that
   apply (simp only: word_neq_0_conv word_less_nat_alt
                     mod_0 unat_word_ariths
                     unat_power_lower word_le_nat_alt)
   apply (metis add_diff_cancel_right' gr0I gr_implies_not0 less_or_eq_imp_le min_def push_bit_eq_0_iff take_bit_nat_eq_self_iff take_bit_push_bit take_bit_take_bit unsigned_push_bit_eq)
   done
 
 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 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 word_le_minus_one_leq:
   "x < y \<Longrightarrow> x \<le> y - 1" for x :: "'a :: len word"
   by transfer (metis le_less_trans less_irrefl take_bit_decr_eq take_bit_nonnegative zle_diff1_eq)
 
 lemma word_less_sub_le[simp]:
   fixes x :: "'a :: len word"
   assumes nv: "n < LENGTH('a)"
   shows "(x \<le> 2 ^ n - 1) = (x < 2 ^ n)"
   using le_less_trans word_le_minus_one_leq nv power_2_ge_iff by blast
 
 lemma unat_of_nat_len:
   "x < 2 ^ LENGTH('a) \<Longrightarrow> unat (of_nat x :: 'a::len word) = x"
   by (simp add: take_bit_nat_eq_self_iff)
 
 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 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 mask_out_sub_mask:
   "(x AND NOT (mask n)) = x - (x AND (mask n))"
   for x :: \<open>'a::len word\<close>
   by (simp add: field_simps word_plus_and_or_coroll2)
 
 lemma subtract_mask:
   "p - (p AND mask n) = (p AND NOT (mask n))"
   "p - (p AND NOT (mask n)) = (p AND mask n)"
   for p :: \<open>'a::len word\<close>
   by (simp add: field_simps word_plus_and_or_coroll2)+
 
 lemma take_bit_word_eq_self_iff:
   \<open>take_bit n w = w \<longleftrightarrow> n \<ge> LENGTH('a) \<or> w < 2 ^ n\<close>
   for w :: \<open>'a::len word\<close>
   using take_bit_int_eq_self_iff [of n \<open>take_bit LENGTH('a) (uint w)\<close>]
   by (transfer fixing: n) auto
 
 lemma word_power_increasing:
   assumes x: "2 ^ x < (2 ^ y::'a::len word)" "x < LENGTH('a::len)" "y < LENGTH('a::len)"
   shows "x < y" using x
   using assms by transfer simp
 
 lemma mask_twice:
   "(x AND mask n) AND mask m = x AND mask (min m n)"
   for x :: \<open>'a::len word\<close>
   by (simp flip: take_bit_eq_mask)
 
 lemma plus_one_helper[elim!]:
   "x < n + (1 :: 'a :: len word) \<Longrightarrow> x \<le> n"
   apply (simp add: word_less_nat_alt word_le_nat_alt field_simps)
   apply (case_tac "1 + n = 0")
    apply simp_all
   apply (subst(asm) unatSuc, assumption)
   apply arith
   done
 
 lemma plus_one_helper2:
   "\<lbrakk> x \<le> n; n + 1 \<noteq> 0 \<rbrakk> \<Longrightarrow> x < n + (1 :: 'a :: len word)"
   by (simp add: word_less_nat_alt word_le_nat_alt field_simps
                 unatSuc)
 
 lemma less_x_plus_1:
   fixes x :: "'a :: len word" shows
   "x \<noteq> - 1 \<Longrightarrow> (y < (x + 1)) = (y < x \<or> y = x)"
   apply (rule iffI)
    apply (rule disjCI)
    apply (drule plus_one_helper)
    apply simp
   apply (subgoal_tac "x < x + 1")
    apply (erule disjE, simp_all)
   apply (rule plus_one_helper2 [OF order_refl])
   apply (rule notI, drule max_word_wrap)
   apply simp
   done
 
 lemma word_Suc_leq:
   fixes k::"'a::len word" shows "k \<noteq> - 1 \<Longrightarrow> x < k + 1 \<longleftrightarrow> x \<le> k"
   using less_x_plus_1 word_le_less_eq by auto
 
 lemma word_Suc_le:
    fixes k::"'a::len word" shows "x \<noteq> - 1 \<Longrightarrow> x + 1 \<le> k \<longleftrightarrow> x < k"
   by (meson not_less word_Suc_leq)
 
 lemma word_lessThan_Suc_atMost:
   \<open>{..< k + 1} = {..k}\<close> if \<open>k \<noteq> - 1\<close> for k :: \<open>'a::len word\<close>
   using that by (simp add: lessThan_def atMost_def word_Suc_leq)
 
 lemma word_atLeastLessThan_Suc_atLeastAtMost:
   \<open>{l ..< u + 1} = {l..u}\<close> if \<open>u \<noteq> - 1\<close> for l :: \<open>'a::len word\<close>
   using that by (simp add: atLeastAtMost_def atLeastLessThan_def word_lessThan_Suc_atMost)
 
 lemma word_atLeastAtMost_Suc_greaterThanAtMost:
   \<open>{m<..u} = {m + 1..u}\<close> if \<open>m \<noteq> - 1\<close> for m :: \<open>'a::len word\<close>
   using that by (simp add: greaterThanAtMost_def greaterThan_def atLeastAtMost_def atLeast_def word_Suc_le)
 
 lemma word_atLeastLessThan_Suc_atLeastAtMost_union:
   fixes l::"'a::len word"
   assumes "m \<noteq> - 1" and "l \<le> m" and "m \<le> u"
   shows "{l..m} \<union> {m+1..u} = {l..u}"
   proof -
   from ivl_disj_un_two(8)[OF assms(2) assms(3)] have "{l..u} = {l..m} \<union> {m<..u}" by blast
   with assms show ?thesis by(simp add: word_atLeastAtMost_Suc_greaterThanAtMost)
   qed
 
 lemma max_word_less_eq_iff [simp]:
   \<open>- 1 \<le> w \<longleftrightarrow> w = - 1\<close> for w :: \<open>'a::len word\<close>
   by (fact word_order.extremum_unique)
 
 lemma word_or_zero:
   "(a OR b = 0) = (a = 0 \<and> b = 0)"
   for a b :: \<open>'a::len word\<close>
   by (fact or_eq_0_iff)
 
 lemma word_2p_mult_inc:
   assumes x: "2 * 2 ^ n < (2::'a::len word) * 2 ^ m"
   assumes suc_n: "Suc n < LENGTH('a::len)"
   shows "2^n < (2::'a::len word)^m"
   by (smt suc_n le_less_trans lessI nat_less_le nat_mult_less_cancel_disj p2_gt_0
           power_Suc power_Suc unat_power_lower word_less_nat_alt x)
 
 lemma power_overflow:
   "n \<ge> LENGTH('a) \<Longrightarrow> 2 ^ n = (0 :: 'a::len word)"
   by simp
 
 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 word_sint_1:
   "sint (1::'a::len word) = (if LENGTH('a) = 1 then -1 else 1)"
   by (fact signed_1)
 
 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
 
 lemma scast_1':
   "(scast (1::'a::len word) :: 'b::len word) =
    (word_of_int (signed_take_bit (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 unat_minus_one_word:
   "unat (-1 :: 'a :: len word) = 2 ^ LENGTH('a) - 1"
   apply (simp only: flip: mask_eq_exp_minus_1)
   apply transfer
   apply (simp add: take_bit_minus_one_eq_mask nat_mask_eq)
   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 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 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 neg_mask_combine:
   "NOT(mask a) AND NOT(mask b) = NOT(mask (max a b) :: 'a::len word)"
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma neg_mask_twice:
   "x AND NOT(mask n) AND NOT(mask m) = x AND NOT(mask (max n m))"
   for x :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma multiple_mask_trivia:
   "n \<ge> m \<Longrightarrow> (x AND NOT(mask n)) + (x AND mask n AND NOT(mask m)) = x AND NOT(mask m)"
   for x :: \<open>'a::len word\<close>
   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 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 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 mask_over_length:
   "LENGTH('a) \<le> n \<Longrightarrow> mask n = (-1::'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 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 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 int_eq_sint:
   "x < 2 ^ (LENGTH('a) - 1) \<Longrightarrow> sint (of_nat x :: 'a :: len word) = int x"
   apply transfer
   apply (rule signed_take_bit_int_eq_self)
    apply simp_all
   apply (metis negative_zle numeral_power_eq_of_nat_cancel_iff)
   done
 
 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)"
   apply (cases \<open>LENGTH('a)\<close>)
   apply simp_all
   apply transfer
   apply (subst signed_take_bit_eq_if_positive)
    apply (simp add: bit_simps)
   apply (metis bit_take_bit_iff nat_less_le order_less_le_trans take_bit_nat_eq_self_iff)
   apply (subst signed_take_bit_eq_if_positive)
     apply (simp add: bit_simps)
   apply (metis bit_take_bit_iff nat_less_le take_bit_nat_eq_self_iff)
     apply (simp flip: of_nat_take_bit add: take_bit_nat_eq_self)
   done
 
 lemma word_le_not_less:
   "((b::'a::len word) \<le> a) = (\<not>(a < b))"
   by fastforce
 
 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 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 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 ucast_less:
   "LENGTH('b) < LENGTH('a) \<Longrightarrow>
    (ucast (x :: 'b :: len word) :: ('a :: len word)) < 2 ^ LENGTH('b)"
   by transfer simp
 
 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)
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps)
   apply (metis bit_take_bit_iff less_mask_eq not_less take_bit_eq_mask)
   done
 
 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
 
 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 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 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 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 (metis unat_of_nat_len)
 
 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 ucast_ucast_mask:
   "(ucast :: 'a :: len word \<Rightarrow> 'b :: len word) (ucast x) = x AND mask (len_of TYPE ('a))"
   apply (simp flip: take_bit_eq_mask)
   apply transfer
   apply (simp add: ac_simps)
   done
 
 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 x :: 'a word) = 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 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
 
 lemma word_div_1:
   "(n :: 'a :: len word) div 1 = n"
   by (fact bits_div_by_1)
 
 lemma word_minus_one_le:
   "-1 \<le> (x :: 'a :: len word) = (x = -1)"
   by (fact word_order.extremum_unique)
 
 lemma up_scast_inj:
       "\<lbrakk> scast x = (scast y :: 'b :: len word); size x \<le> LENGTH('b) \<rbrakk>
          \<Longrightarrow> x = y"
   apply transfer
   apply (cases \<open>LENGTH('a)\<close>)
   apply simp_all
   apply (metis order_refl take_bit_signed_take_bit take_bit_tightened)
   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 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 unat_eq_1:
   \<open>unat x = Suc 0 \<longleftrightarrow> x = 1\<close>
   by (auto intro!: unsigned_word_eqI [where ?'a = nat])
 
 lemma word_unat_Rep_inject1:
   \<open>unat x = unat 1 \<longleftrightarrow> x = 1\<close>
   by (simp add: unat_eq_1)
 
 lemma and_not_mask_twice:
   "(w AND NOT (mask n)) AND NOT (mask m) = w AND NOT (mask (max m n))"
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 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 mask_and_mask:
   "mask a AND mask b = (mask (min a b) :: 'a::len word)"
   by (simp flip: take_bit_eq_mask ac_simps)
 
 lemma mask_eq_0_eq_x:
   "(x AND w = 0) = (x AND NOT w = x)"
   for x w :: \<open>'a::len word\<close>
   using word_plus_and_or_coroll2[where x=x and w=w]
   by auto
 
 lemma mask_eq_x_eq_0:
   "(x AND w = x) = (x AND NOT w = 0)"
   for x w :: \<open>'a::len word\<close>
   using word_plus_and_or_coroll2[where x=x and w=w]
   by auto
 
 lemma compl_of_1: "NOT 1 = (-2 :: 'a :: len word)"
   by (fact not_one)
 
 lemma split_word_eq_on_mask:
   "(x = y) = (x AND m = y AND m \<and> x AND NOT m = y AND NOT m)"
   for x y m :: \<open>'a::len word\<close>
   apply transfer
   apply (simp add: bit_eq_iff)
   apply (auto simp add: bit_simps ac_simps)
   done
 
 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 transfer
   apply (auto simp add: take_bit_of_nat min_def not_le)
   apply (metis linorder_not_less min_def take_bit_nat_eq_self take_bit_take_bit)
   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 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 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 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
 
 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 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 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 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 del: of_nat_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 AND 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 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 auto
   using of_nat_inj apply blast
   done
 
 lemma mask_AND_NOT_mask:
   "(w AND NOT (mask n)) AND mask n = 0"
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (simp add: bit_simps)
 
 lemma AND_NOT_mask_plus_AND_mask_eq:
   "(w AND NOT (mask n)) + (w AND mask n) = w"
   for w :: \<open>'a::len word\<close>
   apply (subst disjunctive_add)
   apply (auto simp add: bit_simps)
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps)
   done
 
 lemma mask_eqI:
   fixes x :: "'a :: len word"
   assumes m1: "x AND mask n = y AND mask n"
   and     m2: "x AND NOT (mask n) = y AND NOT (mask n)"
   shows "x = y"
 proof -
   have *: \<open>x = x AND mask n OR x AND NOT (mask n)\<close> for x :: \<open>'a word\<close>
     by (rule bit_word_eqI) (auto simp add: bit_simps)
   from assms * [of x] * [of y] show ?thesis
     by simp
 qed
 
 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 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_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 mask_Suc_0 : "mask (Suc 0) = (1 :: 'a::len word)"
   by (simp add: mask_eq_decr_exp)
 
 lemma bool_mask':
   fixes x :: "'a :: len word"
   shows "2 < LENGTH('a) \<Longrightarrow> (0 < x AND 1) = (x AND 1 = 1)"
   by (simp add: and_one_eq mod_2_eq_odd)
 
 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 transfer
   apply simp
   apply (subst (2) take_bit_add [symmetric])
   apply (subst take_bit_add [symmetric])
   apply simp
   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 word_0_sle_from_less:
   \<open>0 \<le>s x\<close> if \<open>x < 2 ^ (LENGTH('a) - 1)\<close> for x :: \<open>'a::len word\<close>
   using that
   apply transfer
   apply (cases \<open>LENGTH('a)\<close>)
    apply simp_all
   apply (metis bit_take_bit_iff min_def nat_less_le not_less_eq take_bit_int_eq_self_iff take_bit_take_bit)
   done
 
 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)
 
 lemma sint_minus1 [simp]: "(sint x = -1) = (x = -1)"
   apply (cases \<open>LENGTH('a)\<close>)
    apply simp_all
   apply transfer
   apply (simp flip: signed_take_bit_eq_iff_take_bit_eq)
   done
 
 lemma sint_0 [simp]: "(sint x = 0) = (x = 0)"
   by (fact signed_eq_0_iff)
 
 (* 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 (cases \<open>LENGTH('a)\<close>)
    apply simp_all
   apply transfer
   apply (simp add: signed_take_bit_int_eq_self)
   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 uint_range':
   \<open>0 \<le> uint x \<and> uint x < 2 ^ LENGTH('a)\<close>
   for x :: \<open>'a::len word\<close>
   by transfer simp
 
 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 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 transfer
   apply (simp add: signed_take_bit_take_bit)
   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 transfer
   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
   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
    apply (rule unat_less_helper)
    apply (erule le_less_trans)
   apply (simp_all 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 x \<le> (ucast y :: 'b word)" for x y :: \<open>'a::len word\<close>
   by (auto simp: word_less_nat_alt intro: ucast_mono_le)
 
 lemma neg_mask_add_mask:
   "((x:: 'a :: len word) AND NOT (mask n)) + (2 ^ n - 1) = x OR mask n"
   unfolding mask_2pm1 [symmetric]
   apply (subst word_plus_and_or_coroll; rule bit_word_eqI)
    apply (auto simp add: bit_simps)
   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 AND mask n) AND NOT (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 AND b) AND NOT b = 0"
   for a b :: \<open>'a::len word\<close>
   apply (subst word_bw_assocs(1))
   apply clarsimp
   done
 
 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:"NOT a = x \<Longrightarrow> a = NOT x"
   by auto
 
 lemma test_bit_eq_iff: "bit u = bit v \<longleftrightarrow> u = v"
   for u v :: "'a::len word"
   by (simp add: bit_eq_iff fun_eq_iff)
 
 lemma test_bit_size: "bit w n \<Longrightarrow> n < size w"
   for w :: "'a::len word"
   by transfer simp
 
 lemma word_eq_iff: "x = y \<longleftrightarrow> (\<forall>n<LENGTH('a). bit x n = bit y n)" (is \<open>?P \<longleftrightarrow> ?Q\<close>)
   for x y :: "'a::len word"
   by transfer (auto simp add: bit_eq_iff bit_take_bit_iff)
 
 lemma word_eqI: "(\<And>n. n < size u \<longrightarrow> bit u n = bit v n) \<Longrightarrow> u = v"
   for u :: "'a::len word"
   by (simp add: word_size word_eq_iff)
 
 lemma word_eqD: "u = v \<Longrightarrow> bit u x = bit v x"
   for u v :: "'a::len word"
   by simp
 
 lemma test_bit_bin': "bit w n \<longleftrightarrow> n < size w \<and> bit (uint w) n"
   by transfer (simp add: bit_take_bit_iff)
 
 lemmas test_bit_bin = test_bit_bin' [unfolded word_size]
 
 lemma word_test_bit_def:
   \<open>bit a = bit (uint a)\<close>
   by transfer (simp add: fun_eq_iff bit_take_bit_iff)
 
 lemmas test_bit_def' = word_test_bit_def [THEN fun_cong]
 
 lemma word_test_bit_transfer [transfer_rule]:
   "(rel_fun pcr_word (rel_fun (=) (=)))
     (\<lambda>x n. n < LENGTH('a) \<and> bit x n) (bit :: 'a::len word \<Rightarrow> _)"
   by transfer_prover
 
 lemma test_bit_wi:
   "bit (word_of_int x :: 'a::len word) n \<longleftrightarrow> n < LENGTH('a) \<and> bit x n"
   by transfer simp
 
 lemma word_ops_nth_size:
   "n < size x \<Longrightarrow>
     bit (x OR y) n = (bit x n | bit y n) \<and>
     bit (x AND y) n = (bit x n \<and> bit y n) \<and>
     bit (x XOR y) n = (bit x n \<noteq> bit y n) \<and>
     bit (NOT x) n = (\<not> bit x n)"
   for x :: "'a::len word"
   by transfer (simp add: bit_or_iff bit_and_iff bit_xor_iff bit_not_iff)
 
 lemma word_ao_nth:
   "bit (x OR y) n = (bit x n | bit y n) \<and>
     bit (x AND y) n = (bit x n \<and> bit y n)"
   for x :: "'a::len word"
   by transfer (auto simp add: bit_or_iff bit_and_iff)
 
 lemmas lsb0 = len_gt_0 [THEN word_ops_nth_size [unfolded word_size]]
 
 lemma nth_sint:
   fixes w :: "'a::len word"
   defines "l \<equiv> LENGTH('a)"
   shows "bit (sint w) n = (if n < l - 1 then bit w n else bit w (l - 1))"
   unfolding sint_uint l_def
   by (auto simp: bit_signed_take_bit_iff word_test_bit_def not_less min_def)
 
 lemma test_bit_2p: "bit (word_of_int (2 ^ n)::'a::len word) m \<longleftrightarrow> m = n \<and> m < LENGTH('a)"
   by transfer (auto simp add: bit_exp_iff)
 
 lemma nth_w2p: "bit ((2::'a::len word) ^ n) m \<longleftrightarrow> m = n \<and> m < LENGTH('a::len)"
   by transfer (auto simp add: bit_exp_iff)
 
 lemma bang_is_le: "bit x m \<Longrightarrow> 2 ^ m \<le> x"
   for x :: "'a::len word"
   apply (rule xtrans(3))
    apply (rule_tac [2] y = "x" in le_word_or2)
   apply (rule word_eqI)
   apply (auto simp add: word_ao_nth nth_w2p word_size)
   done
 
 lemmas msb0 = len_gt_0 [THEN diff_Suc_less, THEN word_ops_nth_size [unfolded word_size]]
 lemmas msb1 = msb0 [where i = 0]
 
 lemma test_bit_1 [iff]: "bit (1 :: 'a::len word) n \<longleftrightarrow> n = 0"
   by transfer (auto simp add: bit_1_iff)
 
 lemma nth_0: "\<not> bit (0 :: 'a::len word) n"
   by transfer simp
 
 lemma nth_minus1: "bit (-1 :: 'a::len word) n \<longleftrightarrow> n < LENGTH('a)"
   by transfer simp
 
 lemma nth_ucast:
   "bit (ucast w::'a::len word) n = (bit w n \<and> n < LENGTH('a))"
   by transfer (simp add: bit_take_bit_iff ac_simps)
 
-lemma nth_shiftl1: "bit (shiftl1 w) n \<longleftrightarrow> n < size w \<and> n > 0 \<and> bit w (n - 1)"
-  by transfer (auto simp add: bit_double_iff)
-
-lemma nth_shiftr1: "bit (shiftr1 w) n = bit w (Suc n)"
-  by transfer (auto simp add: bit_take_bit_iff simp flip: bit_Suc)
-
 lemma drop_bit_numeral_bit0_1 [simp]:
   \<open>drop_bit (Suc 0) (numeral k) =
     (word_of_int (drop_bit (Suc 0) (take_bit LENGTH('a) (numeral k))) :: 'a::len word)\<close>
   by (metis Word_eq_word_of_int drop_bit_word.abs_eq of_int_numeral)
 
 lemma nth_mask:
   \<open>bit (mask n :: 'a::len word) i \<longleftrightarrow> i < n \<and> i < size (mask n :: 'a word)\<close>
   by (auto simp add: word_size Word.bit_mask_iff)
 
-lemma nth_sshiftr1: "bit (sshiftr1 w) n = (if n = size w - 1 then bit w n else bit w (Suc n))"
-  apply transfer
-  apply (auto simp add: bit_take_bit_iff bit_signed_take_bit_iff min_def simp flip: bit_Suc)
-  using le_less_Suc_eq apply fastforce
-  using le_less_Suc_eq apply fastforce
-  done
-
 lemma nth_slice: "bit (slice n w :: 'a::len word) m = (bit w (m + n) \<and> m < LENGTH('a))"
   apply (auto simp add: bit_simps less_diff_conv dest: bit_imp_le_length)
   using bit_imp_le_length
   apply fastforce
   done
 
 lemma test_bit_cat [OF refl]:
   "wc = word_cat a b \<Longrightarrow> bit wc n = (n < size wc \<and>
     (if n < size b then bit b n else bit a (n - size b)))"
   apply (simp add: word_size not_less; transfer)
        apply (auto simp add: bit_concat_bit_iff bit_take_bit_iff)
   done
 
 \<comment> \<open>keep quantifiers for use in simplification\<close>
 lemma test_bit_split':
   "word_split c = (a, b) \<longrightarrow>
     (\<forall>n m.
       bit b n = (n < size b \<and> bit c n) \<and>
       bit a m = (m < size a \<and> bit c (m + size b)))"
   by (auto simp add: word_split_bin' bit_unsigned_iff word_size bit_drop_bit_eq ac_simps
            dest: bit_imp_le_length)
 
 lemma test_bit_split:
   "word_split c = (a, b) \<Longrightarrow>
     (\<forall>n::nat. bit b n \<longleftrightarrow> n < size b \<and> bit c n) \<and>
     (\<forall>m::nat. bit a m \<longleftrightarrow> m < size a \<and> bit c (m + size b))"
   by (simp add: test_bit_split')
 
 lemma test_bit_split_eq:
   "word_split c = (a, b) \<longleftrightarrow>
     ((\<forall>n::nat. bit b n = (n < size b \<and> bit c n)) \<and>
      (\<forall>m::nat. bit a m = (m < size a \<and> bit c (m + size b))))"
   apply (rule_tac iffI)
    apply (rule_tac conjI)
     apply (erule test_bit_split [THEN conjunct1])
    apply (erule test_bit_split [THEN conjunct2])
   apply (case_tac "word_split c")
   apply (frule test_bit_split)
   apply (erule trans)
   apply (fastforce intro!: word_eqI simp add: word_size)
   done
 
 lemma test_bit_rcat:
   "sw = size (hd wl) \<Longrightarrow> rc = word_rcat wl \<Longrightarrow> bit rc n =
     (n < size rc \<and> n div sw < size wl \<and> bit ((rev wl) ! (n div sw)) (n mod sw))"
   for wl :: "'a::len word list"
   by (simp add: word_size word_rcat_def rev_map bit_horner_sum_uint_exp_iff bit_simps not_le)
 
 lemmas test_bit_cong = arg_cong [where f = "bit", THEN fun_cong]
 
 lemma max_test_bit: "bit (- 1::'a::len word) n \<longleftrightarrow> n < LENGTH('a)"
   by (fact nth_minus1)
 
 lemma map_nth_0 [simp]: "map (bit (0::'a::len word)) xs = replicate (length xs) False"
   by (simp flip: map_replicate_const)
 
 lemma word_and_1:
   "n AND 1 = (if bit n 0 then 1 else 0)" for n :: "_ word"
   by (rule bit_word_eqI) (auto simp add: bit_and_iff bit_1_iff intro: gr0I)
 
 lemma test_bit_1':
   "bit (1 :: 'a :: len word) n \<longleftrightarrow> 0 < LENGTH('a) \<and> n = 0"
   by simp
 
 lemma nth_w2p_same:
   "bit (2^n :: 'a :: len word) n = (n < LENGTH('a))"
   by (simp add: nth_w2p)
 
 lemma word_leI:
   "(\<And>n.  \<lbrakk>n < size (u::'a::len word); bit u n \<rbrakk> \<Longrightarrow> bit (v::'a::len word) n) \<Longrightarrow> u <= v"
   apply (rule order_trans [of u \<open>u AND v\<close> v])
    apply (rule eq_refl)
    apply (rule bit_word_eqI)
    apply (auto simp add: bit_simps word_and_le1 word_size)
   done
 
 lemma bang_eq:
   fixes x :: "'a::len word"
   shows "(x = y) = (\<forall>n. bit x n = bit y n)"
   by (auto simp add: bit_eq_iff)
 
 lemma neg_mask_test_bit:
   "bit (NOT(mask n) :: 'a :: len word) m = (n \<le> m \<and> m < LENGTH('a))"
   by (auto simp add: bit_simps)
 
 lemma upper_bits_unset_is_l2p:
   \<open>(\<forall>n' \<ge> n. n' < LENGTH('a) \<longrightarrow> \<not> bit p n') \<longleftrightarrow> (p < 2 ^ n)\<close> (is \<open>?P \<longleftrightarrow> ?Q\<close>)
     if \<open>n < LENGTH('a)\<close>
     for p :: "'a :: len word"
 proof
   assume ?Q
   then show ?P
     by (meson bang_is_le le_less_trans not_le word_power_increasing)
 next
   assume ?P
   have \<open>take_bit n p = p\<close>
   proof (rule bit_word_eqI)
     fix q
     assume \<open>q < LENGTH('a)\<close>
     show \<open>bit (take_bit n p) q \<longleftrightarrow> bit p q\<close>
     proof (cases \<open>q < n\<close>)
       case True
       then show ?thesis
         by (auto simp add: bit_simps)
     next
       case False
       then have \<open>n \<le> q\<close>
         by simp
       with \<open>?P\<close> \<open>q < LENGTH('a)\<close> have \<open>\<not> bit p q\<close>
         by simp
       then show ?thesis
         by (simp add: bit_simps)
     qed
   qed
   with that show ?Q
     using take_bit_word_eq_self_iff [of n p] by auto
 qed
 
 lemma less_2p_is_upper_bits_unset:
   "p < 2 ^ n \<longleftrightarrow> n < LENGTH('a) \<and> (\<forall>n' \<ge> n. n' < LENGTH('a) \<longrightarrow> \<not> bit p n')" for p :: "'a :: len word"
   by (meson le_less_trans le_mask_iff_lt_2n upper_bits_unset_is_l2p word_zero_le)
 
 lemma test_bit_over:
   "n \<ge> size (x::'a::len word) \<Longrightarrow> (bit x n) = False"
   by transfer auto
 
 lemma le_mask_high_bits:
   "w \<le> mask n \<longleftrightarrow> (\<forall>i \<in> {n ..< size w}. \<not> bit w i)"
   for w :: \<open>'a::len word\<close>
   apply (auto simp add: bit_simps word_size less_eq_mask_iff_take_bit_eq_self)
    apply (metis bit_take_bit_iff leD)
   apply (metis atLeastLessThan_iff leI take_bit_word_eq_self_iff upper_bits_unset_is_l2p)
   done
 
 lemma test_bit_conj_lt:
   "(bit x m \<and> m < LENGTH('a)) = bit x m" for x :: "'a :: len word"
   using test_bit_bin by blast
 
 lemma neg_test_bit:
   "bit (NOT x) n = (\<not> bit x n \<and> n < LENGTH('a))" for x :: "'a::len word"
   by (cases "n < LENGTH('a)") (auto simp add: test_bit_over word_ops_nth_size word_size)
 
 lemma nth_bounded:
   "\<lbrakk>bit (x :: 'a :: len word) n; x < 2 ^ m; m \<le> len_of TYPE ('a)\<rbrakk> \<Longrightarrow> n < m"
   apply (rule ccontr)
   apply (auto simp add: not_less)
   apply (meson bit_imp_le_length bit_uint_iff less_2p_is_upper_bits_unset test_bit_bin)
   done
 
 lemma and_neq_0_is_nth:
   \<open>x AND y \<noteq> 0 \<longleftrightarrow> bit x n\<close> if \<open>y = 2 ^ n\<close> for x y :: \<open>'a::len word\<close>
   apply (simp add: bit_eq_iff bit_simps)
   using that apply (simp add: bit_simps not_le)
   apply transfer
   apply auto
   done
 
 lemma nth_is_and_neq_0:
   "bit (x::'a::len word) n = (x AND 2 ^ n \<noteq> 0)"
   by (subst and_neq_0_is_nth; rule refl)
 
 lemma max_word_not_less [simp]:
    "\<not> - 1 < x" for x :: \<open>'a::len word\<close>
   by (fact word_order.extremum_strict)
 
 lemma bit_twiddle_min:
   "(y::'a::len word) XOR (((x::'a::len word) XOR y) AND (if x < y then -1 else 0)) = min x y"
   by (rule bit_eqI) (auto simp add: bit_simps)
 
 lemma bit_twiddle_max:
   "(x::'a::len word) XOR (((x::'a::len word) XOR y) AND (if x < y then -1 else 0)) = max x y"
   by (rule bit_eqI) (auto simp add: bit_simps 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 le_mask_imp_and_mask:
   "(x::'a::len word) \<le> mask n \<Longrightarrow> x AND mask n = x"
   by (metis and_mask_eq_iff_le_mask)
 
 lemma or_not_mask_nop:
   "((x::'a::len word) OR NOT (mask n)) AND mask n = x AND 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) OR y AND mask n) AND NOT (mask m) = x AND NOT (mask m)"
   by (rule bit_word_eqI) (auto simp add: bit_simps word_size)
 
 lemma and_mask_0_iff_le_mask:
   fixes w :: "'a::len word"
   shows "(w AND NOT(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) AND mask m) AND mask n = x AND 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 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 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 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> bit x 0"
   using even_plus_one_iff [of x] by simp
 
 lemma odd_iff_lsb:"odd (unat (x::('a::len) word)) = bit x 0"
   by transfer (simp add: even_nat_iff)
 
 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 auto
   apply (case_tac "((of_nat x)::('a::len) word) = of_nat y")
   apply auto
    apply (metis unat_of_nat)
   done
 
 lemma lsb_this_or_next: "\<not> (bit ((x::('a::len) word) + 1) 0) \<Longrightarrow> bit x 0"
   by simp
 
 lemma mask_or_not_mask:
   "x AND mask n OR x AND NOT (mask n) = x"
   for x :: \<open>'a::len word\<close>
   apply (subst word_oa_dist, simp)
   apply (subst word_oa_dist2, simp)
   done
 
 lemma word_gr0_conv_Suc: "(m::'a::len word) > 0 \<Longrightarrow> \<exists>n. m = n + 1"
   by (metis add.commute add_minus_cancel)
 
 end
diff --git a/thys/Word_Lib/Reversed_Bit_Lists.thy b/thys/Word_Lib/Reversed_Bit_Lists.thy
--- a/thys/Word_Lib/Reversed_Bit_Lists.thy
+++ b/thys/Word_Lib/Reversed_Bit_Lists.thy
@@ -1,2286 +1,2281 @@
 (*
  * Copyright Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 (* Author: Jeremy Dawson, NICTA *)
 
 section \<open>Bit values as reversed lists of bools\<close>
 
 theory Reversed_Bit_Lists
   imports
     "HOL-Library.Word"
     Typedef_Morphisms
     Least_significant_bit
     Most_significant_bit
     Even_More_List
     "HOL-Library.Sublist"
     Aligned
+    Legacy_Aliases
 begin
 
 lemma horner_sum_of_bool_2_concat:
   \<open>horner_sum of_bool 2 (concat (map (\<lambda>x. map (bit x) [0..<LENGTH('a)]) ws)) = horner_sum uint (2 ^ LENGTH('a)) ws\<close>
   for ws :: \<open>'a::len word list\<close>
 proof (induction ws)
   case Nil
   then show ?case
     by simp
 next
   case (Cons w ws)
   moreover have \<open>horner_sum of_bool 2 (map (bit w) [0..<LENGTH('a)]) = uint w\<close>
   proof transfer
     fix k :: int
     have \<open>map (\<lambda>n. n < LENGTH('a) \<and> bit k n) [0..<LENGTH('a)]
       = map (bit k) [0..<LENGTH('a)]\<close>
       by simp
     then show \<open>horner_sum of_bool 2 (map (\<lambda>n. n < LENGTH('a) \<and> bit k n) [0..<LENGTH('a)])
       = take_bit LENGTH('a) k\<close>
       by (simp only: horner_sum_bit_eq_take_bit)
   qed
   ultimately show ?case
     by (simp add: horner_sum_append)
 qed
 
 
 subsection \<open>Implicit augmentation of list prefixes\<close>
 
 primrec takefill :: "'a \<Rightarrow> nat \<Rightarrow> 'a list \<Rightarrow> 'a list"
 where
     Z: "takefill fill 0 xs = []"
   | Suc: "takefill fill (Suc n) xs =
       (case xs of
         [] \<Rightarrow> fill # takefill fill n xs
       | y # ys \<Rightarrow> y # takefill fill n ys)"
 
 lemma nth_takefill: "m < n \<Longrightarrow> takefill fill n l ! m = (if m < length l then l ! m else fill)"
   apply (induct n arbitrary: m l)
    apply clarsimp
   apply clarsimp
   apply (case_tac m)
    apply (simp split: list.split)
   apply (simp split: list.split)
   done
 
 lemma takefill_alt: "takefill fill n l = take n l @ replicate (n - length l) fill"
   by (induct n arbitrary: l) (auto split: list.split)
 
 lemma takefill_replicate [simp]: "takefill fill n (replicate m fill) = replicate n fill"
   by (simp add: takefill_alt replicate_add [symmetric])
 
 lemma takefill_le': "n = m + k \<Longrightarrow> takefill x m (takefill x n l) = takefill x m l"
   by (induct m arbitrary: l n) (auto split: list.split)
 
 lemma length_takefill [simp]: "length (takefill fill n l) = n"
   by (simp add: takefill_alt)
 
 lemma take_takefill': "n = k + m \<Longrightarrow> take k (takefill fill n w) = takefill fill k w"
   by (induct k arbitrary: w n) (auto split: list.split)
 
 lemma drop_takefill: "drop k (takefill fill (m + k) w) = takefill fill m (drop k w)"
   by (induct k arbitrary: w) (auto split: list.split)
 
 lemma takefill_le [simp]: "m \<le> n \<Longrightarrow> takefill x m (takefill x n l) = takefill x m l"
   by (auto simp: le_iff_add takefill_le')
 
 lemma take_takefill [simp]: "m \<le> n \<Longrightarrow> take m (takefill fill n w) = takefill fill m w"
   by (auto simp: le_iff_add take_takefill')
 
 lemma takefill_append: "takefill fill (m + length xs) (xs @ w) = xs @ (takefill fill m w)"
   by (induct xs) auto
 
 lemma takefill_same': "l = length xs \<Longrightarrow> takefill fill l xs = xs"
   by (induct xs arbitrary: l) auto
 
 lemmas takefill_same [simp] = takefill_same' [OF refl]
 
 lemma tf_rev:
   "n + k = m + length bl \<Longrightarrow> takefill x m (rev (takefill y n bl)) =
     rev (takefill y m (rev (takefill x k (rev bl))))"
   apply (rule nth_equalityI)
    apply (auto simp add: nth_takefill rev_nth)
   apply (rule_tac f = "\<lambda>n. bl ! n" in arg_cong)
   apply arith
   done
 
 lemma takefill_minus: "0 < n \<Longrightarrow> takefill fill (Suc (n - 1)) w = takefill fill n w"
   by auto
 
 lemmas takefill_Suc_cases =
   list.cases [THEN takefill.Suc [THEN trans]]
 
 lemmas takefill_Suc_Nil = takefill_Suc_cases (1)
 lemmas takefill_Suc_Cons = takefill_Suc_cases (2)
 
 lemmas takefill_minus_simps = takefill_Suc_cases [THEN [2]
   takefill_minus [symmetric, THEN trans]]
 
 lemma takefill_numeral_Nil [simp]:
   "takefill fill (numeral k) [] = fill # takefill fill (pred_numeral k) []"
   by (simp add: numeral_eq_Suc)
 
 lemma takefill_numeral_Cons [simp]:
   "takefill fill (numeral k) (x # xs) = x # takefill fill (pred_numeral k) xs"
   by (simp add: numeral_eq_Suc)
 
 
 subsection \<open>Range projection\<close>
 
 definition bl_of_nth :: "nat \<Rightarrow> (nat \<Rightarrow> 'a) \<Rightarrow> 'a list"
   where "bl_of_nth n f = map f (rev [0..<n])"
 
 lemma bl_of_nth_simps [simp, code]:
   "bl_of_nth 0 f = []"
   "bl_of_nth (Suc n) f = f n # bl_of_nth n f"
   by (simp_all add: bl_of_nth_def)
 
 lemma length_bl_of_nth [simp]: "length (bl_of_nth n f) = n"
   by (simp add: bl_of_nth_def)
 
 lemma nth_bl_of_nth [simp]: "m < n \<Longrightarrow> rev (bl_of_nth n f) ! m = f m"
   by (simp add: bl_of_nth_def rev_map)
 
 lemma bl_of_nth_inj: "(\<And>k. k < n \<Longrightarrow> f k = g k) \<Longrightarrow> bl_of_nth n f = bl_of_nth n g"
   by (simp add: bl_of_nth_def)
 
 lemma bl_of_nth_nth_le: "n \<le> length xs \<Longrightarrow> bl_of_nth n (nth (rev xs)) = drop (length xs - n) xs"
   apply (induct n arbitrary: xs)
    apply clarsimp
   apply clarsimp
   apply (rule trans [OF _ hd_Cons_tl])
    apply (frule Suc_le_lessD)
    apply (simp add: rev_nth trans [OF drop_Suc drop_tl, symmetric])
    apply (subst hd_drop_conv_nth)
     apply force
    apply simp_all
   apply (rule_tac f = "\<lambda>n. drop n xs" in arg_cong)
   apply simp
   done
 
 lemma bl_of_nth_nth [simp]: "bl_of_nth (length xs) ((!) (rev xs)) = xs"
   by (simp add: bl_of_nth_nth_le)
 
 
 subsection \<open>More\<close>
 
 definition rotater1 :: "'a list \<Rightarrow> 'a list"
   where "rotater1 ys =
     (case ys of [] \<Rightarrow> [] | x # xs \<Rightarrow> last ys # butlast ys)"
 
 definition rotater :: "nat \<Rightarrow> 'a list \<Rightarrow> 'a list"
   where "rotater n = rotater1 ^^ n"
 
 lemmas rotater_0' [simp] = rotater_def [where n = "0", simplified]
 
 lemma rotate1_rl': "rotater1 (l @ [a]) = a # l"
   by (cases l) (auto simp: rotater1_def)
 
 lemma rotate1_rl [simp] : "rotater1 (rotate1 l) = l"
   apply (unfold rotater1_def)
   apply (cases "l")
    apply (case_tac [2] "list")
     apply auto
   done
 
 lemma rotate1_lr [simp] : "rotate1 (rotater1 l) = l"
   by (cases l) (auto simp: rotater1_def)
 
 lemma rotater1_rev': "rotater1 (rev xs) = rev (rotate1 xs)"
   by (cases "xs") (simp add: rotater1_def, simp add: rotate1_rl')
 
 lemma rotater_rev': "rotater n (rev xs) = rev (rotate n xs)"
   by (induct n) (auto simp: rotater_def intro: rotater1_rev')
 
 lemma rotater_rev: "rotater n ys = rev (rotate n (rev ys))"
   using rotater_rev' [where xs = "rev ys"] by simp
 
 lemma rotater_drop_take:
   "rotater n xs =
     drop (length xs - n mod length xs) xs @
     take (length xs - n mod length xs) xs"
   by (auto simp: rotater_rev rotate_drop_take rev_take rev_drop)
 
 lemma rotater_Suc [simp]: "rotater (Suc n) xs = rotater1 (rotater n xs)"
   unfolding rotater_def by auto
 
 lemma nth_rotater:
   \<open>rotater m xs ! n = xs ! ((n + (length xs - m mod length xs)) mod length xs)\<close> if \<open>n < length xs\<close>
   using that by (simp add: rotater_drop_take nth_append not_less less_diff_conv ac_simps le_mod_geq)
 
 lemma nth_rotater1:
   \<open>rotater1 xs ! n = xs ! ((n + (length xs - 1)) mod length xs)\<close> if \<open>n < length xs\<close>
   using that nth_rotater [of n xs 1] by simp
 
 lemma rotate_inv_plus [rule_format]:
   "\<forall>k. k = m + n \<longrightarrow> rotater k (rotate n xs) = rotater m xs \<and>
     rotate k (rotater n xs) = rotate m xs \<and>
     rotater n (rotate k xs) = rotate m xs \<and>
     rotate n (rotater k xs) = rotater m xs"
   by (induct n) (auto simp: rotater_def rotate_def intro: funpow_swap1 [THEN trans])
 
 lemmas rotate_inv_rel = le_add_diff_inverse2 [symmetric, THEN rotate_inv_plus]
 
 lemmas rotate_inv_eq = order_refl [THEN rotate_inv_rel, simplified]
 
 lemmas rotate_lr [simp] = rotate_inv_eq [THEN conjunct1]
 lemmas rotate_rl [simp] = rotate_inv_eq [THEN conjunct2, THEN conjunct1]
 
 lemma rotate_gal: "rotater n xs = ys \<longleftrightarrow> rotate n ys = xs"
   by auto
 
 lemma rotate_gal': "ys = rotater n xs \<longleftrightarrow> xs = rotate n ys"
   by auto
 
 lemma length_rotater [simp]: "length (rotater n xs) = length xs"
   by (simp add : rotater_rev)
 
 lemma rotate_eq_mod: "m mod length xs = n mod length xs \<Longrightarrow> rotate m xs = rotate n xs"
   apply (rule box_equals)
     defer
     apply (rule rotate_conv_mod [symmetric])+
   apply simp
   done
 
 lemma restrict_to_left: "x = y \<Longrightarrow> x = z \<longleftrightarrow> y = z"
   by simp
 
 lemmas rotate_eqs =
   trans [OF rotate0 [THEN fun_cong] id_apply]
   rotate_rotate [symmetric]
   rotate_id
   rotate_conv_mod
   rotate_eq_mod
 
 lemmas rrs0 = rotate_eqs [THEN restrict_to_left,
   simplified rotate_gal [symmetric] rotate_gal' [symmetric]]
 lemmas rrs1 = rrs0 [THEN refl [THEN rev_iffD1]]
 lemmas rotater_eqs = rrs1 [simplified length_rotater]
 lemmas rotater_0 = rotater_eqs (1)
 lemmas rotater_add = rotater_eqs (2)
 
 lemma butlast_map: "xs \<noteq> [] \<Longrightarrow> butlast (map f xs) = map f (butlast xs)"
   by (induct xs) auto
 
 lemma rotater1_map: "rotater1 (map f xs) = map f (rotater1 xs)"
   by (cases xs) (auto simp: rotater1_def last_map butlast_map)
 
 lemma rotater_map: "rotater n (map f xs) = map f (rotater n xs)"
   by (induct n) (auto simp: rotater_def rotater1_map)
 
 lemma but_last_zip [rule_format] :
   "\<forall>ys. length xs = length ys \<longrightarrow> xs \<noteq> [] \<longrightarrow>
     last (zip xs ys) = (last xs, last ys) \<and>
     butlast (zip xs ys) = zip (butlast xs) (butlast ys)"
   apply (induct xs)
    apply auto
      apply ((case_tac ys, auto simp: neq_Nil_conv)[1])+
   done
 
 lemma but_last_map2 [rule_format] :
   "\<forall>ys. length xs = length ys \<longrightarrow> xs \<noteq> [] \<longrightarrow>
     last (map2 f xs ys) = f (last xs) (last ys) \<and>
     butlast (map2 f xs ys) = map2 f (butlast xs) (butlast ys)"
   apply (induct xs)
    apply auto
      apply ((case_tac ys, auto simp: neq_Nil_conv)[1])+
   done
 
 lemma rotater1_zip:
   "length xs = length ys \<Longrightarrow>
     rotater1 (zip xs ys) = zip (rotater1 xs) (rotater1 ys)"
   apply (unfold rotater1_def)
   apply (cases xs)
    apply auto
    apply ((case_tac ys, auto simp: neq_Nil_conv but_last_zip)[1])+
   done
 
 lemma rotater1_map2:
   "length xs = length ys \<Longrightarrow>
     rotater1 (map2 f xs ys) = map2 f (rotater1 xs) (rotater1 ys)"
   by (simp add: rotater1_map rotater1_zip)
 
 lemmas lrth =
   box_equals [OF asm_rl length_rotater [symmetric]
                  length_rotater [symmetric],
               THEN rotater1_map2]
 
 lemma rotater_map2:
   "length xs = length ys \<Longrightarrow>
     rotater n (map2 f xs ys) = map2 f (rotater n xs) (rotater n ys)"
   by (induct n) (auto intro!: lrth)
 
 lemma rotate1_map2:
   "length xs = length ys \<Longrightarrow>
     rotate1 (map2 f xs ys) = map2 f (rotate1 xs) (rotate1 ys)"
   by (cases xs; cases ys) auto
 
 lemmas lth = box_equals [OF asm_rl length_rotate [symmetric]
   length_rotate [symmetric], THEN rotate1_map2]
 
 lemma rotate_map2:
   "length xs = length ys \<Longrightarrow>
     rotate n (map2 f xs ys) = map2 f (rotate n xs) (rotate n ys)"
   by (induct n) (auto intro!: lth)
 
 
 subsection \<open>Explicit bit representation of \<^typ>\<open>int\<close>\<close>
 
 primrec bl_to_bin_aux :: "bool list \<Rightarrow> int \<Rightarrow> int"
   where
     Nil: "bl_to_bin_aux [] w = w"
   | Cons: "bl_to_bin_aux (b # bs) w = bl_to_bin_aux bs (of_bool b + 2 * w)"
 
 definition bl_to_bin :: "bool list \<Rightarrow> int"
   where "bl_to_bin bs = bl_to_bin_aux bs 0"
 
 primrec bin_to_bl_aux :: "nat \<Rightarrow> int \<Rightarrow> bool list \<Rightarrow> bool list"
   where
     Z: "bin_to_bl_aux 0 w bl = bl"
   | Suc: "bin_to_bl_aux (Suc n) w bl = bin_to_bl_aux n (w div 2) (odd w # bl)"
 
 definition bin_to_bl :: "nat \<Rightarrow> int \<Rightarrow> bool list"
   where "bin_to_bl n w = bin_to_bl_aux n w []"
 
 lemma bin_to_bl_aux_zero_minus_simp [simp]:
   "0 < n \<Longrightarrow> bin_to_bl_aux n 0 bl = bin_to_bl_aux (n - 1) 0 (False # bl)"
   by (cases n) auto
 
 lemma bin_to_bl_aux_minus1_minus_simp [simp]:
   "0 < n \<Longrightarrow> bin_to_bl_aux n (- 1) bl = bin_to_bl_aux (n - 1) (- 1) (True # bl)"
   by (cases n) auto
 
 lemma bin_to_bl_aux_one_minus_simp [simp]:
   "0 < n \<Longrightarrow> bin_to_bl_aux n 1 bl = bin_to_bl_aux (n - 1) 0 (True # bl)"
   by (cases n) auto
 
 lemma bin_to_bl_aux_Bit0_minus_simp [simp]:
   "0 < n \<Longrightarrow>
     bin_to_bl_aux n (numeral (Num.Bit0 w)) bl = bin_to_bl_aux (n - 1) (numeral w) (False # bl)"
   by (cases n) simp_all
 
 lemma bin_to_bl_aux_Bit1_minus_simp [simp]:
   "0 < n \<Longrightarrow>
     bin_to_bl_aux n (numeral (Num.Bit1 w)) bl = bin_to_bl_aux (n - 1) (numeral w) (True # bl)"
   by (cases n) simp_all
 
 lemma bl_to_bin_aux_append: "bl_to_bin_aux (bs @ cs) w = bl_to_bin_aux cs (bl_to_bin_aux bs w)"
   by (induct bs arbitrary: w) auto
 
 lemma bin_to_bl_aux_append: "bin_to_bl_aux n w bs @ cs = bin_to_bl_aux n w (bs @ cs)"
   by (induct n arbitrary: w bs) auto
 
 lemma bl_to_bin_append: "bl_to_bin (bs @ cs) = bl_to_bin_aux cs (bl_to_bin bs)"
   unfolding bl_to_bin_def by (rule bl_to_bin_aux_append)
 
 lemma bin_to_bl_aux_alt: "bin_to_bl_aux n w bs = bin_to_bl n w @ bs"
   by (simp add: bin_to_bl_def bin_to_bl_aux_append)
 
 lemma bin_to_bl_0 [simp]: "bin_to_bl 0 bs = []"
   by (auto simp: bin_to_bl_def)
 
 lemma size_bin_to_bl_aux: "length (bin_to_bl_aux n w bs) = n + length bs"
   by (induct n arbitrary: w bs) auto
 
 lemma size_bin_to_bl [simp]: "length (bin_to_bl n w) = n"
   by (simp add: bin_to_bl_def size_bin_to_bl_aux)
 
 lemma bl_bin_bl': "bin_to_bl (n + length bs) (bl_to_bin_aux bs w) = bin_to_bl_aux n w bs"
   apply (induct bs arbitrary: w n)
    apply auto
     apply (simp_all only: add_Suc [symmetric])
     apply (auto simp add: bin_to_bl_def)
   done
 
 lemma bl_bin_bl [simp]: "bin_to_bl (length bs) (bl_to_bin bs) = bs"
   unfolding bl_to_bin_def
   apply (rule box_equals)
     apply (rule bl_bin_bl')
    prefer 2
    apply (rule bin_to_bl_aux.Z)
   apply simp
   done
 
 lemma bl_to_bin_inj: "bl_to_bin bs = bl_to_bin cs \<Longrightarrow> length bs = length cs \<Longrightarrow> bs = cs"
   apply (rule_tac box_equals)
     defer
     apply (rule bl_bin_bl)
    apply (rule bl_bin_bl)
   apply simp
   done
 
 lemma bl_to_bin_False [simp]: "bl_to_bin (False # bl) = bl_to_bin bl"
   by (auto simp: bl_to_bin_def)
 
 lemma bl_to_bin_Nil [simp]: "bl_to_bin [] = 0"
   by (auto simp: bl_to_bin_def)
 
 lemma bin_to_bl_zero_aux: "bin_to_bl_aux n 0 bl = replicate n False @ bl"
   by (induct n arbitrary: bl) (auto simp: replicate_app_Cons_same)
 
 lemma bin_to_bl_zero: "bin_to_bl n 0 = replicate n False"
   by (simp add: bin_to_bl_def bin_to_bl_zero_aux)
 
 lemma bin_to_bl_minus1_aux: "bin_to_bl_aux n (- 1) bl = replicate n True @ bl"
   by (induct n arbitrary: bl) (auto simp: replicate_app_Cons_same)
 
 lemma bin_to_bl_minus1: "bin_to_bl n (- 1) = replicate n True"
   by (simp add: bin_to_bl_def bin_to_bl_minus1_aux)
 
 
 subsection \<open>Semantic interpretation of \<^typ>\<open>bool list\<close> as \<^typ>\<open>int\<close>\<close>
 
 lemma bin_bl_bin': "bl_to_bin (bin_to_bl_aux n w bs) = bl_to_bin_aux bs (take_bit n w)"
   by (induct n arbitrary: w bs) (auto simp: bl_to_bin_def take_bit_Suc ac_simps mod_2_eq_odd)
 
 lemma bin_bl_bin [simp]: "bl_to_bin (bin_to_bl n w) = take_bit n w"
   by (auto simp: bin_to_bl_def bin_bl_bin')
 
 lemma bl_to_bin_rep_F: "bl_to_bin (replicate n False @ bl) = bl_to_bin bl"
   by (simp add: bin_to_bl_zero_aux [symmetric] bin_bl_bin') (simp add: bl_to_bin_def)
 
 lemma bin_to_bl_trunc [simp]: "n \<le> m \<Longrightarrow> bin_to_bl n (take_bit m w) = bin_to_bl n w"
   by (auto intro: bl_to_bin_inj)
 
 lemma bin_to_bl_aux_bintr:
   "bin_to_bl_aux n (take_bit m bin) bl =
     replicate (n - m) False @ bin_to_bl_aux (min n m) bin bl"
   apply (induct n arbitrary: m bin bl)
    apply clarsimp
   apply clarsimp
   apply (case_tac "m")
    apply (clarsimp simp: bin_to_bl_zero_aux)
    apply (erule thin_rl)
    apply (induct_tac n)
     apply (auto simp add: take_bit_Suc)
   done
 
 lemma bin_to_bl_bintr:
   "bin_to_bl n (take_bit m bin) = replicate (n - m) False @ bin_to_bl (min n m) bin"
   unfolding bin_to_bl_def by (rule bin_to_bl_aux_bintr)
 
 lemma bl_to_bin_rep_False: "bl_to_bin (replicate n False) = 0"
   by (induct n) auto
 
 lemma len_bin_to_bl_aux: "length (bin_to_bl_aux n w bs) = n + length bs"
   by (fact size_bin_to_bl_aux)
 
 lemma len_bin_to_bl: "length (bin_to_bl n w) = n"
   by (fact size_bin_to_bl) (* FIXME: duplicate *)
 
 lemma sign_bl_bin': "bin_sign (bl_to_bin_aux bs w) = bin_sign w"
   by (induction bs arbitrary: w) (simp_all add: bin_sign_def)
 
 lemma sign_bl_bin: "bin_sign (bl_to_bin bs) = 0"
   by (simp add: bl_to_bin_def sign_bl_bin')
 
 lemma bl_sbin_sign_aux: "hd (bin_to_bl_aux (Suc n) w bs) = (bin_sign (signed_take_bit n w) = -1)"
   by (induction n arbitrary: w bs) (auto simp add: bin_sign_def even_iff_mod_2_eq_zero bit_Suc)
 
 lemma bl_sbin_sign: "hd (bin_to_bl (Suc n) w) = (bin_sign (signed_take_bit n w) = -1)"
   unfolding bin_to_bl_def by (rule bl_sbin_sign_aux)
 
 lemma bin_nth_of_bl_aux:
   "bit (bl_to_bin_aux bl w) n =
     (n < size bl \<and> rev bl ! n \<or> n \<ge> length bl \<and> bit w (n - size bl))"
   apply (induction bl arbitrary: w)
    apply simp_all
   apply safe
                       apply (simp_all add: not_le nth_append bit_double_iff even_bit_succ_iff split: if_splits)
   done
 
 lemma bin_nth_of_bl: "bit (bl_to_bin bl) n = (n < length bl \<and> rev bl ! n)"
   by (simp add: bl_to_bin_def bin_nth_of_bl_aux)
 
 lemma bin_nth_bl: "n < m \<Longrightarrow> bit w n = nth (rev (bin_to_bl m w)) n"
   apply (induct n arbitrary: m w)
    apply clarsimp
    apply (case_tac m, clarsimp)
    apply (clarsimp simp: bin_to_bl_def)
    apply (simp add: bin_to_bl_aux_alt)
   apply (case_tac m, clarsimp)
   apply (clarsimp simp: bin_to_bl_def)
   apply (simp add: bin_to_bl_aux_alt bit_Suc)
   done
 
 lemma nth_bin_to_bl_aux:
   "n < m + length bl \<Longrightarrow> (bin_to_bl_aux m w bl) ! n =
     (if n < m then bit w (m - 1 - n) else bl ! (n - m))"
   apply (induction bl arbitrary: w)
    apply simp_all
    apply (simp add: bin_nth_bl [of \<open>m - Suc n\<close> m] rev_nth flip: bin_to_bl_def)
    apply (metis One_nat_def Suc_pred add_diff_cancel_left'
      add_diff_cancel_right' bin_to_bl_aux_alt bin_to_bl_def
      diff_Suc_Suc diff_is_0_eq diff_zero less_Suc_eq_0_disj
      less_antisym less_imp_Suc_add list.size(3) nat_less_le nth_append size_bin_to_bl_aux)
   done
 
 lemma nth_bin_to_bl: "n < m \<Longrightarrow> (bin_to_bl m w) ! n = bit w (m - Suc n)"
   by (simp add: bin_to_bl_def nth_bin_to_bl_aux)
 
 lemma takefill_bintrunc: "takefill False n bl = rev (bin_to_bl n (bl_to_bin (rev bl)))"
   apply (rule nth_equalityI)
    apply simp
   apply (clarsimp simp: nth_takefill rev_nth nth_bin_to_bl bin_nth_of_bl)
   done
 
 lemma bl_bin_bl_rtf: "bin_to_bl n (bl_to_bin bl) = rev (takefill False n (rev bl))"
   by (simp add: takefill_bintrunc)
 
 lemma bl_to_bin_lt2p_aux: "bl_to_bin_aux bs w < (w + 1) * (2 ^ length bs)"
 proof (induction bs arbitrary: w)
   case Nil
   then show ?case
     by simp
 next
   case (Cons b bs)
   from Cons.IH [of \<open>1 + 2 * w\<close>] Cons.IH [of \<open>2 * w\<close>]
   show ?case
     apply (auto simp add: algebra_simps)
     apply (subst mult_2 [of \<open>2 ^ length bs\<close>])
     apply (simp only: add.assoc)
     apply (rule pos_add_strict)
      apply simp_all
     done
 qed
 
 lemma bl_to_bin_lt2p_drop: "bl_to_bin bs < 2 ^ length (dropWhile Not bs)"
 proof (induct bs)
   case Nil
   then show ?case by simp
 next
   case (Cons b bs)
   with bl_to_bin_lt2p_aux[where w=1] show ?case
     by (simp add: bl_to_bin_def)
 qed
 
 lemma bl_to_bin_lt2p: "bl_to_bin bs < 2 ^ length bs"
   by (metis bin_bl_bin bintr_lt2p bl_bin_bl)
 
 lemma bl_to_bin_ge2p_aux: "bl_to_bin_aux bs w \<ge> w * (2 ^ length bs)"
 proof (induction bs arbitrary: w)
   case Nil
   then show ?case
     by simp
 next
   case (Cons b bs)
   from Cons.IH [of \<open>1 + 2 * w\<close>] Cons.IH [of \<open>2 * w\<close>]
   show ?case
     apply (auto simp add: algebra_simps)
     apply (rule add_le_imp_le_left [of \<open>2 ^ length bs\<close>])
     apply (rule add_increasing)
     apply simp_all
     done
 qed
 
 lemma bl_to_bin_ge0: "bl_to_bin bs \<ge> 0"
   apply (unfold bl_to_bin_def)
   apply (rule xtrans(4))
    apply (rule bl_to_bin_ge2p_aux)
   apply simp
   done
 
 lemma butlast_rest_bin: "butlast (bin_to_bl n w) = bin_to_bl (n - 1) (w div 2)"
   apply (unfold bin_to_bl_def)
   apply (cases n, clarsimp)
   apply clarsimp
   apply (auto simp add: bin_to_bl_aux_alt)
   done
 
 lemma butlast_bin_rest: "butlast bl = bin_to_bl (length bl - Suc 0) (bl_to_bin bl div 2)"
   using butlast_rest_bin [where w="bl_to_bin bl" and n="length bl"] by simp
 
 lemma butlast_rest_bl2bin_aux:
   "bl \<noteq> [] \<Longrightarrow> bl_to_bin_aux (butlast bl) w = bl_to_bin_aux bl w div 2"
   by (induct bl arbitrary: w) auto
 
 lemma butlast_rest_bl2bin: "bl_to_bin (butlast bl) = bl_to_bin bl div 2"
   by (cases bl) (auto simp: bl_to_bin_def butlast_rest_bl2bin_aux)
 
 lemma trunc_bl2bin_aux:
   "take_bit m (bl_to_bin_aux bl w) =
     bl_to_bin_aux (drop (length bl - m) bl) (take_bit (m - length bl) w)"
 proof (induct bl arbitrary: w)
   case Nil
   show ?case by simp
 next
   case (Cons b bl)
   show ?case
   proof (cases "m - length bl")
     case 0
     then have "Suc (length bl) - m = Suc (length bl - m)" by simp
     with Cons show ?thesis by simp
   next
     case (Suc n)
     then have "m - Suc (length bl) = n" by simp
     with Cons Suc show ?thesis by (simp add: take_bit_Suc ac_simps)
   qed
 qed
 
 lemma trunc_bl2bin: "take_bit m (bl_to_bin bl) = bl_to_bin (drop (length bl - m) bl)"
   by (simp add: bl_to_bin_def trunc_bl2bin_aux)
 
 lemma trunc_bl2bin_len [simp]: "take_bit (length bl) (bl_to_bin bl) = bl_to_bin bl"
   by (simp add: trunc_bl2bin)
 
 lemma bl2bin_drop: "bl_to_bin (drop k bl) = take_bit (length bl - k) (bl_to_bin bl)"
   apply (rule trans)
    prefer 2
    apply (rule trunc_bl2bin [symmetric])
   apply (cases "k \<le> length bl")
    apply auto
   done
 
 lemma take_rest_power_bin: "m \<le> n \<Longrightarrow> take m (bin_to_bl n w) = bin_to_bl m (((\<lambda>w. w div 2) ^^ (n - m)) w)"
   apply (rule nth_equalityI)
    apply simp
   apply (clarsimp simp add: nth_bin_to_bl nth_rest_power_bin)
   done
 
 lemma last_bin_last': "size xs > 0 \<Longrightarrow> last xs \<longleftrightarrow> odd (bl_to_bin_aux xs w)"
   by (induct xs arbitrary: w) auto
 
 lemma last_bin_last: "size xs > 0 \<Longrightarrow> last xs \<longleftrightarrow> odd (bl_to_bin xs)"
   unfolding bl_to_bin_def by (erule last_bin_last')
 
 lemma bin_last_last: "odd w \<longleftrightarrow> last (bin_to_bl (Suc n) w)"
   by (simp add: bin_to_bl_def) (auto simp: bin_to_bl_aux_alt)
 
 lemma drop_bin2bl_aux:
   "drop m (bin_to_bl_aux n bin bs) =
     bin_to_bl_aux (n - m) bin (drop (m - n) bs)"
   apply (induction n arbitrary: m bin bs)
    apply auto
   apply (case_tac "m \<le> n")
    apply (auto simp add: not_le Suc_diff_le)
   apply (case_tac "m - n")
    apply auto
   apply (use Suc_diff_Suc in fastforce)
   done
 
 lemma drop_bin2bl: "drop m (bin_to_bl n bin) = bin_to_bl (n - m) bin"
   by (simp add: bin_to_bl_def drop_bin2bl_aux)
 
 lemma take_bin2bl_lem1: "take m (bin_to_bl_aux m w bs) = bin_to_bl m w"
   apply (induct m arbitrary: w bs)
    apply clarsimp
   apply clarsimp
   apply (simp add: bin_to_bl_aux_alt)
   apply (simp add: bin_to_bl_def)
   apply (simp add: bin_to_bl_aux_alt)
   done
 
 lemma take_bin2bl_lem: "take m (bin_to_bl_aux (m + n) w bs) = take m (bin_to_bl (m + n) w)"
   by (induct n arbitrary: w bs) (simp_all (no_asm) add: bin_to_bl_def take_bin2bl_lem1, simp)
 
 lemma bin_split_take: "bin_split n c = (a, b) \<Longrightarrow> bin_to_bl m a = take m (bin_to_bl (m + n) c)"
   apply (induct n arbitrary: b c)
    apply clarsimp
   apply (clarsimp simp: Let_def split: prod.split_asm)
   apply (simp add: bin_to_bl_def)
   apply (simp add: take_bin2bl_lem drop_bit_Suc)
   done
 
 lemma bin_to_bl_drop_bit:
   "k = m + n \<Longrightarrow> bin_to_bl m (drop_bit n c) = take m (bin_to_bl k c)"
   using bin_split_take by simp
 
 lemma bin_split_take1:
   "k = m + n \<Longrightarrow> bin_split n c = (a, b) \<Longrightarrow> bin_to_bl m a = take m (bin_to_bl k c)"
   using bin_split_take by simp
 
 lemma bl_bin_bl_rep_drop:
   "bin_to_bl n (bl_to_bin bl) =
     replicate (n - length bl) False @ drop (length bl - n) bl"
   by (simp add: bl_to_bin_inj bl_to_bin_rep_F trunc_bl2bin)
 
 lemma bl_to_bin_aux_cat:
   "bl_to_bin_aux bs (concat_bit nv v w) =
     concat_bit (nv + length bs) (bl_to_bin_aux bs v) w"
   by (rule bit_eqI)
     (auto simp add: bin_nth_of_bl_aux bin_nth_cat algebra_simps)
 
 lemma bin_to_bl_aux_cat:
   "bin_to_bl_aux (nv + nw) (concat_bit nw w v) bs =
     bin_to_bl_aux nv v (bin_to_bl_aux nw w bs)"
   by (induction nw arbitrary: w bs) (simp_all add: concat_bit_Suc)
 
 lemma bl_to_bin_aux_alt: "bl_to_bin_aux bs w = concat_bit (length bs) (bl_to_bin bs) w"
   using bl_to_bin_aux_cat [where nv = "0" and v = "0"]
   by (simp add: bl_to_bin_def [symmetric])
 
 lemma bin_to_bl_cat:
   "bin_to_bl (nv + nw) (concat_bit nw w v) =
     bin_to_bl_aux nv v (bin_to_bl nw w)"
   by (simp add: bin_to_bl_def bin_to_bl_aux_cat)
 
 lemmas bl_to_bin_aux_app_cat =
   trans [OF bl_to_bin_aux_append bl_to_bin_aux_alt]
 
 lemmas bin_to_bl_aux_cat_app =
   trans [OF bin_to_bl_aux_cat bin_to_bl_aux_alt]
 
 lemma bl_to_bin_app_cat:
   "bl_to_bin (bsa @ bs) = concat_bit (length bs) (bl_to_bin bs) (bl_to_bin bsa)"
   by (simp only: bl_to_bin_aux_app_cat bl_to_bin_def)
 
 lemma bin_to_bl_cat_app:
   "bin_to_bl (n + nw) (concat_bit nw wa w) = bin_to_bl n w @ bin_to_bl nw wa"
   by (simp only: bin_to_bl_def bin_to_bl_aux_cat_app)
 
 text \<open>\<open>bl_to_bin_app_cat_alt\<close> and \<open>bl_to_bin_app_cat\<close> are easily interderivable.\<close>
 lemma bl_to_bin_app_cat_alt: "concat_bit n w (bl_to_bin cs) = bl_to_bin (cs @ bin_to_bl n w)"
   by (simp add: bl_to_bin_app_cat)
 
 lemma mask_lem: "(bl_to_bin (True # replicate n False)) = bl_to_bin (replicate n True) + 1"
   apply (unfold bl_to_bin_def)
   apply (induct n)
    apply simp
   apply (simp only: Suc_eq_plus1 replicate_add append_Cons [symmetric] bl_to_bin_aux_append)
   apply simp
   done
 
 lemma bin_exhaust:
   "(\<And>x b. bin = of_bool b + 2 * x \<Longrightarrow> Q) \<Longrightarrow> Q" for bin :: int
   apply (cases \<open>even bin\<close>)
    apply (auto elim!: evenE oddE)
    apply fastforce
   apply fastforce
   done
 
 primrec rbl_succ :: "bool list \<Rightarrow> bool list"
   where
     Nil: "rbl_succ Nil = Nil"
   | Cons: "rbl_succ (x # xs) = (if x then False # rbl_succ xs else True # xs)"
 
 primrec rbl_pred :: "bool list \<Rightarrow> bool list"
   where
     Nil: "rbl_pred Nil = Nil"
   | Cons: "rbl_pred (x # xs) = (if x then False # xs else True # rbl_pred xs)"
 
 primrec rbl_add :: "bool list \<Rightarrow> bool list \<Rightarrow> bool list"
   where \<comment> \<open>result is length of first arg, second arg may be longer\<close>
     Nil: "rbl_add Nil x = Nil"
   | Cons: "rbl_add (y # ys) x =
       (let ws = rbl_add ys (tl x)
        in (y \<noteq> hd x) # (if hd x \<and> y then rbl_succ ws else ws))"
 
 primrec rbl_mult :: "bool list \<Rightarrow> bool list \<Rightarrow> bool list"
   where \<comment> \<open>result is length of first arg, second arg may be longer\<close>
     Nil: "rbl_mult Nil x = Nil"
   | Cons: "rbl_mult (y # ys) x =
       (let ws = False # rbl_mult ys x
        in if y then rbl_add ws x else ws)"
 
 lemma size_rbl_pred: "length (rbl_pred bl) = length bl"
   by (induct bl) auto
 
 lemma size_rbl_succ: "length (rbl_succ bl) = length bl"
   by (induct bl) auto
 
 lemma size_rbl_add: "length (rbl_add bl cl) = length bl"
   by (induct bl arbitrary: cl) (auto simp: Let_def size_rbl_succ)
 
 lemma size_rbl_mult: "length (rbl_mult bl cl) = length bl"
   by (induct bl arbitrary: cl) (auto simp add: Let_def size_rbl_add)
 
 lemmas rbl_sizes [simp] =
   size_rbl_pred size_rbl_succ size_rbl_add size_rbl_mult
 
 lemmas rbl_Nils =
   rbl_pred.Nil rbl_succ.Nil rbl_add.Nil rbl_mult.Nil
 
 lemma rbl_add_app2: "length blb \<ge> length bla \<Longrightarrow> rbl_add bla (blb @ blc) = rbl_add bla blb"
   apply (induct bla arbitrary: blb)
    apply simp
   apply clarsimp
   apply (case_tac blb, clarsimp)
   apply (clarsimp simp: Let_def)
   done
 
 lemma rbl_add_take2:
   "length blb \<ge> length bla \<Longrightarrow> rbl_add bla (take (length bla) blb) = rbl_add bla blb"
   apply (induct bla arbitrary: blb)
    apply simp
   apply clarsimp
   apply (case_tac blb, clarsimp)
   apply (clarsimp simp: Let_def)
   done
 
 lemma rbl_mult_app2: "length blb \<ge> length bla \<Longrightarrow> rbl_mult bla (blb @ blc) = rbl_mult bla blb"
   apply (induct bla arbitrary: blb)
    apply simp
   apply clarsimp
   apply (case_tac blb, clarsimp)
   apply (clarsimp simp: Let_def rbl_add_app2)
   done
 
 lemma rbl_mult_take2:
   "length blb \<ge> length bla \<Longrightarrow> rbl_mult bla (take (length bla) blb) = rbl_mult bla blb"
   apply (rule trans)
    apply (rule rbl_mult_app2 [symmetric])
    apply simp
   apply (rule_tac f = "rbl_mult bla" in arg_cong)
   apply (rule append_take_drop_id)
   done
 
 lemma rbl_add_split:
   "P (rbl_add (y # ys) (x # xs)) =
     (\<forall>ws. length ws = length ys \<longrightarrow> ws = rbl_add ys xs \<longrightarrow>
       (y \<longrightarrow> ((x \<longrightarrow> P (False # rbl_succ ws)) \<and> (\<not> x \<longrightarrow> P (True # ws)))) \<and>
       (\<not> y \<longrightarrow> P (x # ws)))"
   by (cases y) (auto simp: Let_def)
 
 lemma rbl_mult_split:
   "P (rbl_mult (y # ys) xs) =
     (\<forall>ws. length ws = Suc (length ys) \<longrightarrow> ws = False # rbl_mult ys xs \<longrightarrow>
       (y \<longrightarrow> P (rbl_add ws xs)) \<and> (\<not> y \<longrightarrow> P ws))"
   by (auto simp: Let_def)
 
 lemma rbl_pred: "rbl_pred (rev (bin_to_bl n bin)) = rev (bin_to_bl n (bin - 1))"
 proof (unfold bin_to_bl_def, induction n arbitrary: bin)
   case 0
   then show ?case
     by simp
 next
   case (Suc n)
   obtain b k where \<open>bin = of_bool b + 2 * k\<close>
     using bin_exhaust by blast
   moreover have \<open>(2 * k - 1) div 2 = k - 1\<close>
     using even_succ_div_2 [of \<open>2 * (k - 1)\<close>]
     by simp
   ultimately show ?case
     using Suc [of \<open>bin div 2\<close>]
     by simp (auto simp add: bin_to_bl_aux_alt)
 qed
 
 lemma rbl_succ: "rbl_succ (rev (bin_to_bl n bin)) = rev (bin_to_bl n (bin + 1))"
   apply (unfold bin_to_bl_def)
   apply (induction n arbitrary: bin)
    apply simp_all
   apply (case_tac bin rule: bin_exhaust)
    apply (simp_all add: bin_to_bl_aux_alt ac_simps)
   done
 
 lemma rbl_add:
   "\<And>bina binb. rbl_add (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb)) =
     rev (bin_to_bl n (bina + binb))"
   apply (unfold bin_to_bl_def)
   apply (induct n)
    apply simp
   apply clarsimp
   apply (case_tac bina rule: bin_exhaust)
   apply (case_tac binb rule: bin_exhaust)
   apply (case_tac b)
    apply (case_tac [!] "ba")
      apply (auto simp: rbl_succ bin_to_bl_aux_alt Let_def ac_simps)
   done
 
 lemma rbl_add_long:
   "m \<ge> n \<Longrightarrow> rbl_add (rev (bin_to_bl n bina)) (rev (bin_to_bl m binb)) =
     rev (bin_to_bl n (bina + binb))"
   apply (rule box_equals [OF _ rbl_add_take2 rbl_add])
    apply (rule_tac f = "rbl_add (rev (bin_to_bl n bina))" in arg_cong)
    apply (rule rev_swap [THEN iffD1])
    apply (simp add: rev_take drop_bin2bl)
   apply simp
   done
 
 lemma rbl_mult_gt1:
   "m \<ge> length bl \<Longrightarrow>
     rbl_mult bl (rev (bin_to_bl m binb)) =
     rbl_mult bl (rev (bin_to_bl (length bl) binb))"
   apply (rule trans)
    apply (rule rbl_mult_take2 [symmetric])
    apply simp_all
   apply (rule_tac f = "rbl_mult bl" in arg_cong)
   apply (rule rev_swap [THEN iffD1])
   apply (simp add: rev_take drop_bin2bl)
   done
 
 lemma rbl_mult_gt:
   "m > n \<Longrightarrow>
     rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl m binb)) =
     rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb))"
   by (auto intro: trans [OF rbl_mult_gt1])
 
 lemmas rbl_mult_Suc = lessI [THEN rbl_mult_gt]
 
 lemma rbbl_Cons: "b # rev (bin_to_bl n x) = rev (bin_to_bl (Suc n) (of_bool b + 2 * x))"
   by (simp add: bin_to_bl_def) (simp add: bin_to_bl_aux_alt)
 
 lemma rbl_mult:
   "rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb)) =
     rev (bin_to_bl n (bina * binb))"
   apply (induct n arbitrary: bina binb)
    apply simp_all
   apply (unfold bin_to_bl_def)
   apply clarsimp
   apply (case_tac bina rule: bin_exhaust)
   apply (case_tac binb rule: bin_exhaust)
   apply (simp_all add: bin_to_bl_aux_alt)
   apply (simp_all add: rbbl_Cons rbl_mult_Suc rbl_add algebra_simps)
   done
 
 lemma sclem: "size (concat (map (bin_to_bl n) xs)) = length xs * n"
   by (simp add: length_concat comp_def sum_list_triv)
 
 lemma bin_cat_foldl_lem:
   "foldl (\<lambda>u k. concat_bit n k u) x xs =
     concat_bit (size xs * n) (foldl (\<lambda>u k. concat_bit n k u) y xs) x"
   apply (induct xs arbitrary: x)
    apply simp
   apply (simp (no_asm))
   apply (frule asm_rl)
   apply (drule meta_spec)
   apply (erule trans)
   apply (drule_tac x = "concat_bit n a y" in meta_spec)
   apply (simp add: bin_cat_assoc_sym)
   done
 
 lemma bin_rcat_bl: "bin_rcat n wl = bl_to_bin (concat (map (bin_to_bl n) wl))"
   apply (unfold bin_rcat_eq_foldl)
   apply (rule sym)
   apply (induct wl)
    apply (auto simp add: bl_to_bin_append)
   apply (simp add: bl_to_bin_aux_alt sclem)
   apply (simp add: bin_cat_foldl_lem [symmetric])
   done
 
 lemma bin_last_bl_to_bin: "odd (bl_to_bin bs) \<longleftrightarrow> bs \<noteq> [] \<and> last bs"
 by(cases "bs = []")(auto simp add: bl_to_bin_def last_bin_last'[where w=0])
 
 lemma bin_rest_bl_to_bin: "bl_to_bin bs div 2 = bl_to_bin (butlast bs)"
 by(cases "bs = []")(simp_all add: bl_to_bin_def butlast_rest_bl2bin_aux)
 
 lemma bl_xor_aux_bin:
   "map2 (\<lambda>x y. x \<noteq> y) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) =
     bin_to_bl_aux n (v XOR w) (map2 (\<lambda>x y. x \<noteq> y) bs cs)"
   apply (induction n arbitrary: v w bs cs)
    apply auto
   apply (case_tac v rule: bin_exhaust)
   apply (case_tac w rule: bin_exhaust)
   apply clarsimp
   done
 
 lemma bl_or_aux_bin:
   "map2 (\<or>) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) =
     bin_to_bl_aux n (v OR w) (map2 (\<or>) bs cs)"
   by (induct n arbitrary: v w bs cs) simp_all
 
 lemma bl_and_aux_bin:
   "map2 (\<and>) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) =
     bin_to_bl_aux n (v AND w) (map2 (\<and>) bs cs)"
   by (induction n arbitrary: v w bs cs) simp_all
 
 lemma bl_not_aux_bin: "map Not (bin_to_bl_aux n w cs) = bin_to_bl_aux n (NOT w) (map Not cs)"
   by (induct n arbitrary: w cs) auto
 
 lemma bl_not_bin: "map Not (bin_to_bl n w) = bin_to_bl n (NOT w)"
   by (simp add: bin_to_bl_def bl_not_aux_bin)
 
 lemma bl_and_bin: "map2 (\<and>) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v AND w)"
   by (simp add: bin_to_bl_def bl_and_aux_bin)
 
 lemma bl_or_bin: "map2 (\<or>) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v OR w)"
   by (simp add: bin_to_bl_def bl_or_aux_bin)
 
 lemma bl_xor_bin: "map2 (\<noteq>) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v XOR w)"
   using bl_xor_aux_bin by (simp add: bin_to_bl_def)
 
 
 subsection \<open>Type \<^typ>\<open>'a word\<close>\<close>
 
 lift_definition of_bl :: \<open>bool list \<Rightarrow> 'a::len word\<close>
   is bl_to_bin .
 
 lift_definition to_bl :: \<open>'a::len word \<Rightarrow> bool list\<close>
   is \<open>bin_to_bl LENGTH('a)\<close>
   by (simp add: bl_to_bin_inj)
 
 lemma to_bl_eq:
   \<open>to_bl w = bin_to_bl (LENGTH('a)) (uint w)\<close>
   for w :: \<open>'a::len word\<close>
   by transfer simp
 
 lemma bit_of_bl_iff [bit_simps]:
   \<open>bit (of_bl bs :: 'a word) n \<longleftrightarrow> rev bs ! n \<and> n < LENGTH('a::len) \<and> n < length bs\<close>
   by transfer (simp add: bin_nth_of_bl ac_simps)
 
 lemma rev_to_bl_eq:
   \<open>rev (to_bl w) = map (bit w) [0..<LENGTH('a)]\<close>
   for w :: \<open>'a::len word\<close>
   apply (rule nth_equalityI)
    apply (simp add: to_bl.rep_eq)
   apply (simp add: bin_nth_bl bit_word.rep_eq to_bl.rep_eq)
   done
 
 lemma to_bl_eq_rev:
   \<open>to_bl w = map (bit w) (rev [0..<LENGTH('a)])\<close>
   for w :: \<open>'a::len word\<close>
   using rev_to_bl_eq [of w]
   apply (subst rev_is_rev_conv [symmetric])
   apply (simp add: rev_map)
   done
 
 lemma of_bl_rev_eq:
   \<open>of_bl (rev bs) = horner_sum of_bool 2 bs\<close>
   apply (rule bit_word_eqI)
   apply (simp add: bit_of_bl_iff)
   apply transfer
   apply (simp add: bit_horner_sum_bit_iff ac_simps)
   done
 
 lemma of_bl_eq:
   \<open>of_bl bs = horner_sum of_bool 2 (rev bs)\<close>
   using of_bl_rev_eq [of \<open>rev bs\<close>] by simp
 
 lemma bshiftr1_eq:
   \<open>bshiftr1 b w = of_bl (b # butlast (to_bl w))\<close>
-  apply transfer
-  apply auto
-   apply (subst bl_to_bin_app_cat [of \<open>[True]\<close>, simplified])
-   apply simp
-   apply (metis One_nat_def add.commute bin_bl_bin bin_last_bl_to_bin bin_rest_bl_to_bin butlast_bin_rest concat_bit_eq last.simps list.distinct(1) list.size(3) list.size(4) odd_iff_mod_2_eq_one plus_1_eq_Suc power_Suc0_right push_bit_of_1 size_bin_to_bl take_bit_eq_mod trunc_bl2bin_len)
-  apply (simp add: butlast_rest_bl2bin)
+  apply (rule bit_word_eqI)
+  apply (auto simp add: bit_simps to_bl_eq_rev nth_append rev_nth nth_butlast not_less simp flip: bit_Suc)
+  apply (metis Suc_pred len_gt_0 less_eq_decr_length_iff not_bit_length verit_la_disequality)
   done
 
 lemma length_to_bl_eq:
   \<open>length (to_bl w) = LENGTH('a)\<close>
   for w :: \<open>'a::len word\<close>
   by transfer simp
 
 lemma word_rotr_eq:
   \<open>word_rotr n w = of_bl (rotater n (to_bl w))\<close>
   apply (rule bit_word_eqI)
   subgoal for n
     apply (cases \<open>n < LENGTH('a)\<close>)
      apply (simp_all add: bit_word_rotr_iff bit_of_bl_iff rotater_rev length_to_bl_eq nth_rotate rev_to_bl_eq ac_simps)
     done
   done
 
 lemma word_rotl_eq:
   \<open>word_rotl n w = of_bl (rotate n (to_bl w))\<close>
 proof -
   have \<open>rotate n (to_bl w) = rev (rotater n (rev (to_bl w)))\<close>
     by (simp add: rotater_rev')
   then show ?thesis
     apply (simp add: word_rotl_eq_word_rotr bit_of_bl_iff length_to_bl_eq rev_to_bl_eq)
     apply (rule bit_word_eqI)
     subgoal for n
       apply (cases \<open>n < LENGTH('a)\<close>)
        apply (simp_all add: bit_word_rotr_iff bit_of_bl_iff nth_rotater)
       done
     done
 qed
 
 lemma to_bl_def': "(to_bl :: 'a::len word \<Rightarrow> bool list) = bin_to_bl (LENGTH('a)) \<circ> uint"
   by transfer (simp add: fun_eq_iff)
 
 \<comment> \<open>type definitions theorem for in terms of equivalent bool list\<close>
 lemma td_bl:
   "type_definition
     (to_bl :: 'a::len word \<Rightarrow> bool list)
     of_bl
     {bl. length bl = LENGTH('a)}"
   apply (standard; transfer)
   apply (auto dest: sym)
   done
 
 interpretation word_bl:
   type_definition
     "to_bl :: 'a::len word \<Rightarrow> bool list"
     of_bl
     "{bl. length bl = LENGTH('a::len)}"
   by (fact td_bl)
 
 lemmas word_bl_Rep' = word_bl.Rep [unfolded mem_Collect_eq, iff]
 
 lemma word_size_bl: "size w = size (to_bl w)"
   by (auto simp: word_size)
 
 lemma to_bl_use_of_bl: "to_bl w = bl \<longleftrightarrow> w = of_bl bl \<and> length bl = length (to_bl w)"
   by (fastforce elim!: word_bl.Abs_inverse [unfolded mem_Collect_eq])
 
 lemma length_bl_gt_0 [iff]: "0 < length (to_bl x)"
   for x :: "'a::len word"
   unfolding word_bl_Rep' by (rule len_gt_0)
 
 lemma bl_not_Nil [iff]: "to_bl x \<noteq> []"
   for x :: "'a::len word"
   by (fact length_bl_gt_0 [unfolded length_greater_0_conv])
 
 lemma length_bl_neq_0 [iff]: "length (to_bl x) \<noteq> 0"
   for x :: "'a::len word"
   by (fact length_bl_gt_0 [THEN gr_implies_not0])
 
 lemma hd_bl_sign_sint: "hd (to_bl w) = (bin_sign (sint w) = -1)"
   apply transfer
   apply (auto simp add: bin_sign_def)
   using bin_sign_lem bl_sbin_sign apply fastforce
   using bin_sign_lem bl_sbin_sign apply force
   done
 
 lemma of_bl_drop':
   "lend = length bl - LENGTH('a::len) \<Longrightarrow>
     of_bl (drop lend bl) = (of_bl bl :: 'a word)"
   by transfer (simp flip: trunc_bl2bin)
 
 lemma test_bit_of_bl:
   "bit (of_bl bl::'a::len word) n = (rev bl ! n \<and> n < LENGTH('a) \<and> n < length bl)"
   by transfer (simp add: bin_nth_of_bl ac_simps)
 
 lemma no_of_bl: "(numeral bin ::'a::len word) = of_bl (bin_to_bl (LENGTH('a)) (numeral bin))"
   by transfer simp
 
 lemma uint_bl: "to_bl w = bin_to_bl (size w) (uint w)"
   by transfer simp
 
 lemma to_bl_bin: "bl_to_bin (to_bl w) = uint w"
   by (simp add: uint_bl word_size)
 
 lemma to_bl_of_bin: "to_bl (word_of_int bin::'a::len word) = bin_to_bl (LENGTH('a)) bin"
   by (auto simp: uint_bl word_ubin.eq_norm word_size)
 
 lemma to_bl_numeral [simp]:
   "to_bl (numeral bin::'a::len word) =
     bin_to_bl (LENGTH('a)) (numeral bin)"
   unfolding word_numeral_alt by (rule to_bl_of_bin)
 
 lemma to_bl_neg_numeral [simp]:
   "to_bl (- numeral bin::'a::len word) =
     bin_to_bl (LENGTH('a)) (- numeral bin)"
   unfolding word_neg_numeral_alt by (rule to_bl_of_bin)
 
 lemma to_bl_to_bin [simp] : "bl_to_bin (to_bl w) = uint w"
   by (simp add: uint_bl word_size)
 
 lemma uint_bl_bin: "bl_to_bin (bin_to_bl (LENGTH('a)) (uint x)) = uint x"
   for x :: "'a::len word"
   by (rule trans [OF bin_bl_bin word_ubin.norm_Rep])
 
 lemma ucast_bl: "ucast w = of_bl (to_bl w)"
   by transfer simp
 
 lemma ucast_down_bl:
   \<open>(ucast :: 'a::len word \<Rightarrow> 'b::len word) (of_bl bl) = of_bl bl\<close>
     if \<open>is_down (ucast :: 'a::len word \<Rightarrow> 'b::len word)\<close>
   using that by transfer simp
 
 lemma of_bl_append_same: "of_bl (X @ to_bl w) = w"
   by transfer (simp add: bl_to_bin_app_cat)
 
 lemma ucast_of_bl_up:
   \<open>ucast (of_bl bl :: 'a::len word) = of_bl bl\<close>
   if \<open>size bl \<le> size (of_bl bl :: 'a::len word)\<close>
   using that
   apply transfer
   apply (rule bit_eqI)
   apply (auto simp add: bit_take_bit_iff)
   apply (subst (asm) trunc_bl2bin_len [symmetric])
   apply (auto simp only: bit_take_bit_iff)
   done
 
 lemma word_rev_tf:
   "to_bl (of_bl bl::'a::len word) =
     rev (takefill False (LENGTH('a)) (rev bl))"
   by transfer (simp add: bl_bin_bl_rtf)
 
 lemma word_rep_drop:
   "to_bl (of_bl bl::'a::len word) =
     replicate (LENGTH('a) - length bl) False @
     drop (length bl - LENGTH('a)) bl"
   by (simp add: word_rev_tf takefill_alt rev_take)
 
 lemma to_bl_ucast:
   "to_bl (ucast (w::'b::len word) ::'a::len word) =
     replicate (LENGTH('a) - LENGTH('b)) False @
     drop (LENGTH('b) - LENGTH('a)) (to_bl w)"
   apply (unfold ucast_bl)
   apply (rule trans)
    apply (rule word_rep_drop)
   apply simp
   done
 
 lemma ucast_up_app:
   \<open>to_bl (ucast w :: 'b::len word) = replicate n False @ (to_bl w)\<close>
     if \<open>source_size (ucast :: 'a word \<Rightarrow> 'b word) + n = target_size (ucast :: 'a word \<Rightarrow> 'b word)\<close>
     for w :: \<open>'a::len word\<close>
   using that
   by (auto simp add : source_size target_size to_bl_ucast)
 
 lemma ucast_down_drop [OF refl]:
   "uc = ucast \<Longrightarrow> source_size uc = target_size uc + n \<Longrightarrow>
     to_bl (uc w) = drop n (to_bl w)"
   by (auto simp add : source_size target_size to_bl_ucast)
 
 lemma scast_down_drop [OF refl]:
   "sc = scast \<Longrightarrow> source_size sc = target_size sc + n \<Longrightarrow>
     to_bl (sc w) = drop n (to_bl w)"
   apply (subgoal_tac "sc = ucast")
    apply safe
    apply simp
    apply (erule ucast_down_drop)
   apply (rule down_cast_same [symmetric])
   apply (simp add : source_size target_size is_down)
   done
 
 lemma word_0_bl [simp]: "of_bl [] = 0"
   by transfer simp
 
 lemma word_1_bl: "of_bl [True] = 1"
   by transfer (simp add: bl_to_bin_def)
 
 lemma of_bl_0 [simp]: "of_bl (replicate n False) = 0"
   by transfer (simp add: bl_to_bin_rep_False)
 
 lemma to_bl_0 [simp]: "to_bl (0::'a::len word) = replicate (LENGTH('a)) False"
   by (simp add: uint_bl word_size bin_to_bl_zero)
 
 \<comment> \<open>links with \<open>rbl\<close> operations\<close>
 lemma word_succ_rbl: "to_bl w = bl \<Longrightarrow> to_bl (word_succ w) = rev (rbl_succ (rev bl))"
   by transfer (simp add: rbl_succ)
 
 lemma word_pred_rbl: "to_bl w = bl \<Longrightarrow> to_bl (word_pred w) = rev (rbl_pred (rev bl))"
   by transfer (simp add: rbl_pred)
 
 lemma word_add_rbl:
   "to_bl v = vbl \<Longrightarrow> to_bl w = wbl \<Longrightarrow>
     to_bl (v + w) = rev (rbl_add (rev vbl) (rev wbl))"
   apply transfer
   apply (drule sym)
   apply (drule sym)
   apply (simp add: rbl_add)
   done
 
 lemma word_mult_rbl:
   "to_bl v = vbl \<Longrightarrow> to_bl w = wbl \<Longrightarrow>
     to_bl (v * w) = rev (rbl_mult (rev vbl) (rev wbl))"
   apply transfer
   apply (drule sym)
   apply (drule sym)
   apply (simp add: rbl_mult)
   done
 
 lemma rtb_rbl_ariths:
   "rev (to_bl w) = ys \<Longrightarrow> rev (to_bl (word_succ w)) = rbl_succ ys"
   "rev (to_bl w) = ys \<Longrightarrow> rev (to_bl (word_pred w)) = rbl_pred ys"
   "rev (to_bl v) = ys \<Longrightarrow> rev (to_bl w) = xs \<Longrightarrow> rev (to_bl (v * w)) = rbl_mult ys xs"
   "rev (to_bl v) = ys \<Longrightarrow> rev (to_bl w) = xs \<Longrightarrow> rev (to_bl (v + w)) = rbl_add ys xs"
   by (auto simp: rev_swap [symmetric] word_succ_rbl word_pred_rbl word_mult_rbl word_add_rbl)
 
 lemma of_bl_length_less:
   \<open>(of_bl x :: 'a::len word) < 2 ^ k\<close>
     if \<open>length x = k\<close> \<open>k < LENGTH('a)\<close>
 proof -
   from that have \<open>length x < LENGTH('a)\<close>
     by simp
   then have \<open>(of_bl x :: 'a::len word) < 2 ^ length x\<close>
     apply (simp add: of_bl_eq)
     apply transfer
     apply (simp add: take_bit_horner_sum_bit_eq)
     apply (subst length_rev [symmetric])
     apply (simp only: horner_sum_of_bool_2_less)
     done
   with that show ?thesis
     by simp
 qed
 
 lemma word_eq_rbl_eq: "x = y \<longleftrightarrow> rev (to_bl x) = rev (to_bl y)"
   by simp
 
 lemma bl_word_not: "to_bl (NOT w) = map Not (to_bl w)"
   by transfer (simp add: bl_not_bin)
 
 lemma bl_word_xor: "to_bl (v XOR w) = map2 (\<noteq>) (to_bl v) (to_bl w)"
   by transfer (simp flip: bl_xor_bin)
 
 lemma bl_word_or: "to_bl (v OR w) = map2 (\<or>) (to_bl v) (to_bl w)"
   by transfer (simp flip: bl_or_bin)
 
 lemma bl_word_and: "to_bl (v AND w) = map2 (\<and>) (to_bl v) (to_bl w)"
   by transfer (simp flip: bl_and_bin)
 
 lemma bin_nth_uint': "bit (uint w) n \<longleftrightarrow> rev (bin_to_bl (size w) (uint w)) ! n \<and> n < size w"
   apply (unfold word_size)
   apply (safe elim!: bin_nth_uint_imp)
    apply (frule bin_nth_uint_imp)
    apply (fast dest!: bin_nth_bl)+
   done
 
 lemmas bin_nth_uint = bin_nth_uint' [unfolded word_size]
 
 lemma test_bit_bl: "bit w n \<longleftrightarrow> rev (to_bl w) ! n \<and> n < size w"
   by transfer (auto simp add: bin_nth_bl)
 
 lemma to_bl_nth: "n < size w \<Longrightarrow> to_bl w ! n = bit w (size w - Suc n)"
   by (simp add: word_size rev_nth test_bit_bl)
 
 lemma map_bit_interval_eq:
   \<open>map (bit w) [0..<n] = takefill False n (rev (to_bl w))\<close> for w :: \<open>'a::len word\<close>
 proof (rule nth_equalityI)
   show \<open>length (map (bit w) [0..<n]) =
     length (takefill False n (rev (to_bl w)))\<close>
     by simp
   fix m
   assume \<open>m < length (map (bit w) [0..<n])\<close>
   then have \<open>m < n\<close>
     by simp
   then have \<open>bit w m \<longleftrightarrow> takefill False n (rev (to_bl w)) ! m\<close>
     by (auto simp add: nth_takefill not_less rev_nth to_bl_nth word_size dest: bit_imp_le_length)
   with \<open>m < n \<close>show \<open>map (bit w) [0..<n] ! m \<longleftrightarrow> takefill False n (rev (to_bl w)) ! m\<close>
     by simp
 qed
 
 lemma to_bl_unfold:
   \<open>to_bl w = rev (map (bit w) [0..<LENGTH('a)])\<close> for w :: \<open>'a::len word\<close>
   by (simp add: map_bit_interval_eq takefill_bintrunc to_bl_def flip: bin_to_bl_def)
 
 lemma nth_rev_to_bl:
   \<open>rev (to_bl w) ! n \<longleftrightarrow> bit w n\<close>
   if \<open>n < LENGTH('a)\<close> for w :: \<open>'a::len word\<close>
   using that by (simp add: to_bl_unfold)
 
 lemma nth_to_bl:
   \<open>to_bl w ! n \<longleftrightarrow> bit w (LENGTH('a) - Suc n)\<close>
   if \<open>n < LENGTH('a)\<close> for w :: \<open>'a::len word\<close>
   using that by (simp add: to_bl_unfold rev_nth)
 
 lemma of_bl_rep_False: "of_bl (replicate n False @ bs) = of_bl bs"
   by (auto simp: of_bl_def bl_to_bin_rep_F)
 
 lemma [code abstract]:
   \<open>Word.the_int (of_bl bs :: 'a word) = horner_sum of_bool 2 (take LENGTH('a::len) (rev bs))\<close>
   apply (simp add: of_bl_eq flip: take_bit_horner_sum_bit_eq)
   apply transfer
   apply simp
   done
 
 lemma [code]:
   \<open>to_bl w = map (bit w) (rev [0..<LENGTH('a::len)])\<close>
   for w :: \<open>'a::len word\<close>
   by (fact to_bl_eq_rev)
 
 lemma word_reverse_eq_of_bl_rev_to_bl:
   \<open>word_reverse w = of_bl (rev (to_bl w))\<close>
   by (rule bit_word_eqI)
     (auto simp add: bit_word_reverse_iff bit_of_bl_iff nth_to_bl)
 
 lemmas word_reverse_no_def [simp] =
   word_reverse_eq_of_bl_rev_to_bl [of "numeral w"] for w
 
 lemma to_bl_word_rev: "to_bl (word_reverse w) = rev (to_bl w)"
   by (rule nth_equalityI) (simp_all add: nth_rev_to_bl word_reverse_def word_rep_drop flip: of_bl_eq)
 
 lemma to_bl_n1 [simp]: "to_bl (-1::'a::len word) = replicate (LENGTH('a)) True"
   apply (rule word_bl.Abs_inverse')
    apply simp
   apply (rule word_eqI)
   apply (clarsimp simp add: word_size)
   apply (auto simp add: word_bl.Abs_inverse test_bit_bl word_size)
   done
 
 lemma rbl_word_or: "rev (to_bl (x OR y)) = map2 (\<or>) (rev (to_bl x)) (rev (to_bl y))"
   by (simp add: zip_rev bl_word_or rev_map)
 
 lemma rbl_word_and: "rev (to_bl (x AND y)) = map2 (\<and>) (rev (to_bl x)) (rev (to_bl y))"
   by (simp add: zip_rev bl_word_and rev_map)
 
 lemma rbl_word_xor: "rev (to_bl (x XOR y)) = map2 (\<noteq>) (rev (to_bl x)) (rev (to_bl y))"
   by (simp add: zip_rev bl_word_xor rev_map)
 
 lemma rbl_word_not: "rev (to_bl (NOT x)) = map Not (rev (to_bl x))"
   by (simp add: bl_word_not rev_map)
 
 lemma bshiftr1_numeral [simp]:
   \<open>bshiftr1 b (numeral w :: 'a word) = of_bl (b # butlast (bin_to_bl LENGTH('a::len) (numeral w)))\<close>
-  by (simp add: bshiftr1_eq)
+  by (rule bit_word_eqI) (auto simp add: bit_simps rev_nth nth_append nth_butlast nth_bin_to_bl simp flip: bit_Suc)
 
 lemma bshiftr1_bl: "to_bl (bshiftr1 b w) = b # butlast (to_bl w)"
   unfolding bshiftr1_eq by (rule word_bl.Abs_inverse) simp
 
 lemma shiftl1_of_bl: "shiftl1 (of_bl bl) = of_bl (bl @ [False])"
   by transfer (simp add: bl_to_bin_append)
 
 lemma shiftl1_bl: "shiftl1 w = of_bl (to_bl w @ [False])"
   for w :: "'a::len word"
 proof -
   have "shiftl1 w = shiftl1 (of_bl (to_bl w))"
     by simp
   also have "\<dots> = of_bl (to_bl w @ [False])"
     by (rule shiftl1_of_bl)
   finally show ?thesis .
 qed
 
 lemma bl_shiftl1: "to_bl (shiftl1 w) = tl (to_bl w) @ [False]"
   for w :: "'a::len word"
   by (simp add: shiftl1_bl word_rep_drop drop_Suc drop_Cons') (fast intro!: Suc_leI)
 
 \<comment> \<open>Generalized version of \<open>bl_shiftl1\<close>. Maybe this one should replace it?\<close>
 lemma bl_shiftl1': "to_bl (shiftl1 w) = tl (to_bl w @ [False])"
   by (simp add: shiftl1_bl word_rep_drop drop_Suc del: drop_append)
 
 lemma shiftr1_bl:
   \<open>shiftr1 w = of_bl (butlast (to_bl w))\<close>
 proof (rule bit_word_eqI)
   fix n
   assume \<open>n < LENGTH('a)\<close>
   show \<open>bit (shiftr1 w) n \<longleftrightarrow> bit (of_bl (butlast (to_bl w)) :: 'a word) n\<close>
   proof (cases \<open>n = LENGTH('a) - 1\<close>)
     case True
     then show ?thesis
       by (simp add: bit_shiftr1_iff bit_of_bl_iff)
   next
     case False
     with \<open>n < LENGTH('a)\<close>
     have \<open>n < LENGTH('a) - 1\<close>
       by simp
     with \<open>n < LENGTH('a)\<close> show ?thesis
       by (simp add: bit_shiftr1_iff bit_of_bl_iff rev_nth nth_butlast
         word_size to_bl_nth)
   qed
 qed
 
 lemma bl_shiftr1: "to_bl (shiftr1 w) = False # butlast (to_bl w)"
   for w :: "'a::len word"
   by (simp add: shiftr1_bl word_rep_drop len_gt_0 [THEN Suc_leI])
 
 \<comment> \<open>Generalized version of \<open>bl_shiftr1\<close>. Maybe this one should replace it?\<close>
 lemma bl_shiftr1': "to_bl (shiftr1 w) = butlast (False # to_bl w)"
   apply (rule word_bl.Abs_inverse')
    apply (simp del: butlast.simps)
   apply (simp add: shiftr1_bl of_bl_def)
   done
 
 lemma bl_sshiftr1: "to_bl (sshiftr1 w) = hd (to_bl w) # butlast (to_bl w)"
   for w :: "'a::len word"
 proof (rule nth_equalityI)
   fix n
   assume \<open>n < length (to_bl (sshiftr1 w))\<close>
   then have \<open>n < LENGTH('a)\<close>
     by simp
   then show \<open>to_bl (sshiftr1 w) ! n \<longleftrightarrow> (hd (to_bl w) # butlast (to_bl w)) ! n\<close>
     apply (cases n)
      apply (simp_all add: to_bl_nth word_size hd_conv_nth bit_sshiftr1_iff nth_butlast Suc_diff_Suc nth_to_bl)
     done
 qed simp
 
 lemma drop_shiftr: "drop n (to_bl (w >> n)) = take (size w - n) (to_bl w)"
   for w :: "'a::len word"
   apply (unfold shiftr_def)
   apply (induct n)
    prefer 2
    apply (simp add: drop_Suc bl_shiftr1 butlast_drop [symmetric])
    apply (rule butlast_take [THEN trans])
     apply (auto simp: word_size)
   done
 
 lemma drop_sshiftr: "drop n (to_bl (w >>> n)) = take (size w - n) (to_bl w)"
   for w :: "'a::len word"
    apply (simp_all add: word_size sshiftr_eq)
   apply (rule nth_equalityI)
    apply (simp_all add: word_size nth_to_bl bit_signed_drop_bit_iff)
   done
 
 lemma take_shiftr: "n \<le> size w \<Longrightarrow> take n (to_bl (w >> n)) = replicate n False"
   apply (unfold shiftr_def)
   apply (induct n)
    prefer 2
    apply (simp add: bl_shiftr1' length_0_conv [symmetric] word_size)
    apply (rule take_butlast [THEN trans])
     apply (auto simp: word_size)
   done
 
 lemma take_sshiftr':
   "n \<le> size w \<Longrightarrow> hd (to_bl (w >>> n)) = hd (to_bl w) \<and>
     take n (to_bl (w >>> n)) = replicate n (hd (to_bl w))"
   for w :: "'a::len word"
   apply (auto simp add: sshiftr_eq hd_bl_sign_sint bin_sign_def not_le word_size sint_signed_drop_bit_eq)
   apply (rule nth_equalityI)
     apply (auto simp add: nth_to_bl bit_signed_drop_bit_iff bit_last_iff)
   apply (rule nth_equalityI)
    apply (auto simp add: nth_to_bl bit_signed_drop_bit_iff bit_last_iff)
   done
 
 lemmas hd_sshiftr = take_sshiftr' [THEN conjunct1]
 lemmas take_sshiftr = take_sshiftr' [THEN conjunct2]
 
 lemma atd_lem: "take n xs = t \<Longrightarrow> drop n xs = d \<Longrightarrow> xs = t @ d"
   by (auto intro: append_take_drop_id [symmetric])
 
 lemmas bl_shiftr = atd_lem [OF take_shiftr drop_shiftr]
 lemmas bl_sshiftr = atd_lem [OF take_sshiftr drop_sshiftr]
 
 lemma shiftl_of_bl: "of_bl bl << n = of_bl (bl @ replicate n False)"
   by (induct n) (auto simp: shiftl_def shiftl1_of_bl replicate_app_Cons_same)
 
 lemma shiftl_bl: "w << n = of_bl (to_bl w @ replicate n False)"
   for w :: "'a::len word"
 proof -
   have "w << n = of_bl (to_bl w) << n"
     by simp
   also have "\<dots> = of_bl (to_bl w @ replicate n False)"
     by (rule shiftl_of_bl)
   finally show ?thesis .
 qed
 
 lemma bl_shiftl: "to_bl (w << n) = drop n (to_bl w) @ replicate (min (size w) n) False"
   by (simp add: shiftl_bl word_rep_drop word_size)
 
 lemma shiftr1_bl_of:
   "length bl \<le> LENGTH('a) \<Longrightarrow>
     shiftr1 (of_bl bl::'a::len word) = of_bl (butlast bl)"
-  by transfer (simp add: butlast_rest_bl2bin trunc_bl2bin)
+  apply (cases bl rule: rev_cases)
+  apply simp_all
+  apply (rule bit_word_eqI)
+  apply (auto simp add: bit_simps simp flip: bit_Suc)
+  done
 
 lemma shiftr_bl_of:
   "length bl \<le> LENGTH('a) \<Longrightarrow>
     (of_bl bl::'a::len word) >> n = of_bl (take (length bl - n) bl)"
-  apply (unfold shiftr_def)
-  apply (induct n)
-   apply clarsimp
-  apply clarsimp
-  apply (subst shiftr1_bl_of)
-   apply simp
-  apply (simp add: butlast_take)
-  done
+  by (rule bit_word_eqI) (auto simp add: bit_simps rev_nth)
 
 lemma shiftr_bl: "x >> n \<equiv> of_bl (take (LENGTH('a) - n) (to_bl x))"
   for x :: "'a::len word"
   using shiftr_bl_of [where 'a='a, of "to_bl x"] by simp
 
 lemma aligned_bl_add_size [OF refl]:
   "size x - n = m \<Longrightarrow> n \<le> size x \<Longrightarrow> drop m (to_bl x) = replicate n False \<Longrightarrow>
     take m (to_bl y) = replicate m False \<Longrightarrow>
     to_bl (x + y) = take m (to_bl x) @ drop m (to_bl y)" for x :: \<open>'a::len word\<close>
   apply (subgoal_tac "x AND y = 0")
    prefer 2
    apply (rule word_bl.Rep_eqD)
    apply (simp add: bl_word_and)
    apply (rule align_lem_and [THEN trans])
        apply (simp_all add: word_size)[5]
    apply simp
   apply (subst word_plus_and_or [symmetric])
   apply (simp add : bl_word_or)
   apply (rule align_lem_or)
      apply (simp_all add: word_size)
   done
 
 lemma mask_bl: "mask n = of_bl (replicate n True)"
   by (auto simp add: bit_simps intro!: word_eqI)
 
 lemma bl_and_mask':
   "to_bl (w AND mask n :: 'a::len word) =
     replicate (LENGTH('a) - n) False @
     drop (LENGTH('a) - n) (to_bl w)"
   apply (rule nth_equalityI)
    apply simp
   apply (clarsimp simp add: to_bl_nth word_size bit_simps)
   apply (auto simp add: word_size test_bit_bl nth_append rev_nth)
   done
 
 lemma slice1_eq_of_bl:
   \<open>(slice1 n w :: 'b::len word) = of_bl (takefill False n (to_bl w))\<close>
   for w :: \<open>'a::len word\<close>
 proof (rule bit_word_eqI)
   fix m
   assume \<open>m < LENGTH('b)\<close>
   show \<open>bit (slice1 n w :: 'b::len word) m \<longleftrightarrow> bit (of_bl (takefill False n (to_bl w)) :: 'b word) m\<close>
     by (cases \<open>m \<ge> n\<close>; cases \<open>LENGTH('a) \<ge> n\<close>)
       (auto simp add: bit_slice1_iff bit_of_bl_iff not_less rev_nth not_le nth_takefill nth_to_bl algebra_simps)
 qed
 
 lemma slice1_no_bin [simp]:
   "slice1 n (numeral w :: 'b word) = of_bl (takefill False n (bin_to_bl (LENGTH('b::len)) (numeral w)))"
   by (simp add: slice1_eq_of_bl) (* TODO: neg_numeral *)
 
 lemma slice_no_bin [simp]:
   "slice n (numeral w :: 'b word) = of_bl (takefill False (LENGTH('b::len) - n)
     (bin_to_bl (LENGTH('b::len)) (numeral w)))"
   by (simp add: slice_def) (* TODO: neg_numeral *)
 
 lemma slice_take': "slice n w = of_bl (take (size w - n) (to_bl w))"
   by (simp add: slice_def word_size slice1_eq_of_bl takefill_alt)
 
 lemmas slice_take = slice_take' [unfolded word_size]
 
 \<comment> \<open>shiftr to a word of the same size is just slice,
     slice is just shiftr then ucast\<close>
 lemmas shiftr_slice = trans [OF shiftr_bl [THEN meta_eq_to_obj_eq] slice_take [symmetric]]
 
 lemma slice1_down_alt':
   "sl = slice1 n w \<Longrightarrow> fs = size sl \<Longrightarrow> fs + k = n \<Longrightarrow>
     to_bl sl = takefill False fs (drop k (to_bl w))"
   apply (simp add: slice1_eq_of_bl)
   apply transfer
   apply (simp add: bl_bin_bl_rep_drop)
   using drop_takefill
   apply force
   done
 
 lemma slice1_up_alt':
   "sl = slice1 n w \<Longrightarrow> fs = size sl \<Longrightarrow> fs = n + k \<Longrightarrow>
     to_bl sl = takefill False fs (replicate k False @ (to_bl w))"
   apply (simp add: slice1_eq_of_bl)
   apply transfer
   apply (simp add: bl_bin_bl_rep_drop flip: takefill_append)
   apply (metis diff_add_inverse)
   done
 
 lemmas sd1 = slice1_down_alt' [OF refl refl, unfolded word_size]
 lemmas su1 = slice1_up_alt' [OF refl refl, unfolded word_size]
 lemmas slice1_down_alt = le_add_diff_inverse [THEN sd1]
 lemmas slice1_up_alts =
   le_add_diff_inverse [symmetric, THEN su1]
   le_add_diff_inverse2 [symmetric, THEN su1]
 
 lemma slice1_tf_tf':
   "to_bl (slice1 n w :: 'a::len word) =
     rev (takefill False (LENGTH('a)) (rev (takefill False n (to_bl w))))"
   unfolding slice1_eq_of_bl by (rule word_rev_tf)
 
 lemmas slice1_tf_tf = slice1_tf_tf' [THEN word_bl.Rep_inverse', symmetric]
 
 lemma revcast_eq_of_bl:
   \<open>(revcast w :: 'b::len word) = of_bl (takefill False (LENGTH('b)) (to_bl w))\<close>
   for w :: \<open>'a::len word\<close>
   by (simp add: revcast_def slice1_eq_of_bl)
 
 lemmas revcast_no_def [simp] = revcast_eq_of_bl [where w="numeral w", unfolded word_size] for w
 
 lemma to_bl_revcast:
   "to_bl (revcast w :: 'a::len word) = takefill False (LENGTH('a)) (to_bl w)"
   apply (rule nth_equalityI)
   apply simp
   apply (cases \<open>LENGTH('a) \<le> LENGTH('b)\<close>)
    apply (auto simp add: nth_to_bl nth_takefill bit_revcast_iff)
   done
 
 lemma word_cat_bl: "word_cat a b = of_bl (to_bl a @ to_bl b)"
   apply (rule bit_word_eqI)
   apply (simp add: bit_word_cat_iff bit_of_bl_iff nth_append not_less nth_rev_to_bl)
   apply (meson bit_word.rep_eq less_diff_conv2 nth_rev_to_bl)
   done
 
 lemma of_bl_append:
   "(of_bl (xs @ ys) :: 'a::len word) = of_bl xs * 2^(length ys) + of_bl ys"
   apply transfer
   apply (simp add: bl_to_bin_app_cat bin_cat_num)
   done
 
 lemma of_bl_False [simp]: "of_bl (False#xs) = of_bl xs"
   by (rule word_eqI) (auto simp: test_bit_of_bl nth_append)
 
 lemma of_bl_True [simp]: "(of_bl (True # xs) :: 'a::len word) = 2^length xs + of_bl xs"
   by (subst of_bl_append [where xs="[True]", simplified]) (simp add: word_1_bl)
 
 lemma of_bl_Cons: "of_bl (x#xs) = of_bool x * 2^length xs + of_bl xs"
   by (cases x) simp_all
 
 lemma word_split_bl':
   "std = size c - size b \<Longrightarrow> (word_split c = (a, b)) \<Longrightarrow>
     (a = of_bl (take std (to_bl c)) \<and> b = of_bl (drop std (to_bl c)))"
   apply (simp add: word_split_def)
   apply transfer
   apply (cases \<open>LENGTH('b) \<le> LENGTH('a)\<close>)
    apply (auto simp add: drop_bit_take_bit drop_bin2bl bin_to_bl_drop_bit [symmetric, of \<open>LENGTH('a)\<close> \<open>LENGTH('a) - LENGTH('b)\<close> \<open>LENGTH('b)\<close>] min_absorb2)
   done
 
 lemma word_split_bl: "std = size c - size b \<Longrightarrow>
     (a = of_bl (take std (to_bl c)) \<and> b = of_bl (drop std (to_bl c))) \<longleftrightarrow>
     word_split c = (a, b)"
   apply (rule iffI)
    defer
    apply (erule (1) word_split_bl')
   apply (case_tac "word_split c")
   apply (auto simp add: word_size)
   apply (frule word_split_bl' [rotated])
    apply (auto simp add: word_size)
   done
 
 lemma word_split_bl_eq:
   "(word_split c :: ('c::len word \<times> 'd::len word)) =
     (of_bl (take (LENGTH('a::len) - LENGTH('d::len)) (to_bl c)),
      of_bl (drop (LENGTH('a) - LENGTH('d)) (to_bl c)))"
   for c :: "'a::len word"
   apply (rule word_split_bl [THEN iffD1])
    apply (unfold word_size)
    apply (rule refl conjI)+
   done
 
 lemma word_rcat_bl:
   \<open>word_rcat wl = of_bl (concat (map to_bl wl))\<close>
 proof -
   define ws where \<open>ws = rev wl\<close>
   moreover have \<open>word_rcat (rev ws) = of_bl (concat (map to_bl (rev ws)))\<close>
     apply (simp add: word_rcat_def of_bl_eq rev_concat rev_map comp_def rev_to_bl_eq flip: horner_sum_of_bool_2_concat)
     apply transfer
     apply simp
     done
   ultimately show ?thesis
     by simp
 qed
 
 lemma size_rcat_lem': "size (concat (map to_bl wl)) = length wl * size (hd wl)"
   by (induct wl) (auto simp: word_size)
 
 lemmas size_rcat_lem = size_rcat_lem' [unfolded word_size]
 
 lemma nth_rcat_lem:
   "n < length (wl::'a word list) * LENGTH('a::len) \<Longrightarrow>
     rev (concat (map to_bl wl)) ! n =
     rev (to_bl (rev wl ! (n div LENGTH('a)))) ! (n mod LENGTH('a))"
   apply (induct wl)
    apply clarsimp
   apply (clarsimp simp add : nth_append size_rcat_lem)
   apply (simp flip: mult_Suc minus_div_mult_eq_mod add: less_Suc_eq_le not_less)
   apply (metis (no_types, lifting) diff_is_0_eq div_le_mono len_not_eq_0 less_Suc_eq less_mult_imp_div_less nonzero_mult_div_cancel_right not_le nth_Cons_0)
   done
 
 lemma foldl_eq_foldr: "foldl (+) x xs = foldr (+) (x # xs) 0"
   for x :: "'a::comm_monoid_add"
   by (induct xs arbitrary: x) (auto simp: add.assoc)
 
 lemmas word_cat_bl_no_bin [simp] =
   word_cat_bl [where a="numeral a" and b="numeral b", unfolded to_bl_numeral]
   for a b (* FIXME: negative numerals, 0 and 1 *)
 
 lemmas word_split_bl_no_bin [simp] =
   word_split_bl_eq [where c="numeral c", unfolded to_bl_numeral] for c
 
 lemmas word_rot_defs = word_roti_eq_word_rotr_word_rotl word_rotr_eq word_rotl_eq
 
 lemma to_bl_rotl: "to_bl (word_rotl n w) = rotate n (to_bl w)"
   by (simp add: word_rotl_eq to_bl_use_of_bl)
 
 lemmas blrs0 = rotate_eqs [THEN to_bl_rotl [THEN trans]]
 
 lemmas word_rotl_eqs =
   blrs0 [simplified word_bl_Rep' word_bl.Rep_inject to_bl_rotl [symmetric]]
 
 lemma to_bl_rotr: "to_bl (word_rotr n w) = rotater n (to_bl w)"
   by (simp add: word_rotr_eq to_bl_use_of_bl)
 
 lemmas brrs0 = rotater_eqs [THEN to_bl_rotr [THEN trans]]
 
 lemmas word_rotr_eqs =
   brrs0 [simplified word_bl_Rep' word_bl.Rep_inject to_bl_rotr [symmetric]]
 
 declare word_rotr_eqs (1) [simp]
 declare word_rotl_eqs (1) [simp]
 
 lemmas abl_cong = arg_cong [where f = "of_bl"]
 
 locale word_rotate
 begin
 
 lemmas word_rot_defs' = to_bl_rotl to_bl_rotr
 
 lemmas blwl_syms [symmetric] = bl_word_not bl_word_and bl_word_or bl_word_xor
 
 lemmas lbl_lbl = trans [OF word_bl_Rep' word_bl_Rep' [symmetric]]
 
 lemmas ths_map2 [OF lbl_lbl] = rotate_map2 rotater_map2
 
 lemmas ths_map [where xs = "to_bl v"] = rotate_map rotater_map for v
 
 lemmas th1s [simplified word_rot_defs' [symmetric]] = ths_map2 ths_map
 
 end
 
 lemmas bl_word_rotl_dt = trans [OF to_bl_rotl rotate_drop_take,
   simplified word_bl_Rep']
 
 lemmas bl_word_rotr_dt = trans [OF to_bl_rotr rotater_drop_take,
   simplified word_bl_Rep']
 
 lemma bl_word_roti_dt':
   "n = nat ((- i) mod int (size (w :: 'a::len word))) \<Longrightarrow>
     to_bl (word_roti i w) = drop n (to_bl w) @ take n (to_bl w)"
   apply (unfold word_roti_eq_word_rotr_word_rotl)
   apply (simp add: bl_word_rotl_dt bl_word_rotr_dt word_size)
   apply safe
    apply (simp add: zmod_zminus1_eq_if)
    apply safe
     apply (simp add: nat_mult_distrib)
    apply (simp add: nat_diff_distrib [OF pos_mod_sign pos_mod_conj
                                       [THEN conjunct2, THEN order_less_imp_le]]
                     nat_mod_distrib)
   apply (simp add: nat_mod_distrib)
   done
 
 lemmas bl_word_roti_dt = bl_word_roti_dt' [unfolded word_size]
 
 lemmas word_rotl_dt = bl_word_rotl_dt [THEN word_bl.Rep_inverse' [symmetric]]
 lemmas word_rotr_dt = bl_word_rotr_dt [THEN word_bl.Rep_inverse' [symmetric]]
 lemmas word_roti_dt = bl_word_roti_dt [THEN word_bl.Rep_inverse' [symmetric]]
 
 lemmas word_rotr_dt_no_bin' [simp] =
   word_rotr_dt [where w="numeral w", unfolded to_bl_numeral] for w
   (* FIXME: negative numerals, 0 and 1 *)
 
 lemmas word_rotl_dt_no_bin' [simp] =
   word_rotl_dt [where w="numeral w", unfolded to_bl_numeral] for w
   (* FIXME: negative numerals, 0 and 1 *)
 
 lemma max_word_bl: "to_bl (- 1::'a::len word) = replicate LENGTH('a) True"
   by (fact to_bl_n1)
 
 lemma to_bl_mask:
   "to_bl (mask n :: 'a::len word) =
   replicate (LENGTH('a) - n) False @
     replicate (min (LENGTH('a)) n) True"
   by (simp add: mask_bl word_rep_drop min_def)
 
 lemma map_replicate_True:
   "n = length xs \<Longrightarrow>
     map (\<lambda>(x,y). x \<and> y) (zip xs (replicate n True)) = xs"
   by (induct xs arbitrary: n) auto
 
 lemma map_replicate_False:
   "n = length xs \<Longrightarrow> map (\<lambda>(x,y). x \<and> y)
     (zip xs (replicate n False)) = replicate n False"
   by (induct xs arbitrary: n) auto
 
 lemma bl_and_mask:
   fixes w :: "'a::len word"
     and n :: nat
   defines "n' \<equiv> LENGTH('a) - n"
   shows "to_bl (w AND mask n) = replicate n' False @ drop n' (to_bl w)"
 proof -
   note [simp] = map_replicate_True map_replicate_False
   have "to_bl (w AND mask n) = map2 (\<and>) (to_bl w) (to_bl (mask n::'a::len word))"
     by (simp add: bl_word_and)
   also have "to_bl w = take n' (to_bl w) @ drop n' (to_bl w)"
     by simp
   also have "map2 (\<and>) \<dots> (to_bl (mask n::'a::len word)) =
       replicate n' False @ drop n' (to_bl w)"
     unfolding to_bl_mask n'_def by (subst zip_append) auto
   finally show ?thesis .
 qed
 
 lemma drop_rev_takefill:
   "length xs \<le> n \<Longrightarrow>
     drop (n - length xs) (rev (takefill False n (rev xs))) = xs"
   by (simp add: takefill_alt rev_take)
 
 declare bin_to_bl_def [simp]
 
 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_and_1_bl:
   fixes x::"'a::len word"
   shows "(x AND 1) = of_bl [bit x 0]"
   by (simp add: mod_2_eq_odd and_one_eq)
 
 lemma word_1_and_bl:
   fixes x::"'a::len word"
   shows "(1 AND x) = of_bl [bit x 0]"
   by (simp add: mod_2_eq_odd one_and_eq)
 
 lemma of_bl_drop:
   "of_bl (drop n xs) = (of_bl xs AND mask (length xs - n))"
   apply (rule bit_word_eqI)
   apply (auto simp: rev_nth bit_simps cong: rev_conj_cong)
   done
 
 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 eq_zero_set_bl:
   "(w = 0) = (True \<notin> set (to_bl w))"
   apply (auto simp add: to_bl_unfold)
   apply (rule bit_word_eqI)
   apply auto
   done
 
 lemma of_drop_to_bl:
   "of_bl (drop n (to_bl x)) = (x AND mask (size x - n))"
   by (simp add: of_bl_drop word_size_bl)
 
 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 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 word_msb_alt: "msb w \<longleftrightarrow> hd (to_bl w)"
   for w :: "'a::len word"
   apply (simp add: msb_word_eq)
   apply (subst hd_conv_nth)
    apply simp
   apply (subst nth_to_bl)
    apply simp
   apply simp
   done
 
 lemma word_lsb_last:
   \<open>lsb w \<longleftrightarrow> last (to_bl w)\<close>
   for w :: \<open>'a::len word\<close>
   using nth_to_bl [of \<open>LENGTH('a) - Suc 0\<close> w]
   by (simp add: lsb_odd last_conv_nth)
 
 lemma is_aligned_to_bl:
   "is_aligned (w :: 'a :: len word) n = (True \<notin> set (drop (size w - n) (to_bl w)))"
   by (simp add: is_aligned_mask eq_zero_set_bl bl_and_mask word_size)
 
 lemma is_aligned_replicate:
   fixes w::"'a::len word"
   assumes aligned: "is_aligned w n"
   and          nv: "n \<le> LENGTH('a)"
   shows   "to_bl w = (take (LENGTH('a) - n) (to_bl w)) @ replicate n False"
 proof -
   from nv have rl: "\<And>q. q < 2 ^ (LENGTH('a) - n) \<Longrightarrow>
       to_bl (2 ^ n * (of_nat q :: 'a word)) =
       drop n (to_bl (of_nat q :: 'a word)) @ replicate n False"
     by (metis bl_shiftl le_antisym min_def shiftl_t2n wsst_TYs(3))
   show ?thesis using aligned
     by (auto simp: rl elim: is_alignedE)
 qed
 
 lemma is_aligned_drop:
   fixes w::"'a::len word"
   assumes "is_aligned w n" "n \<le> LENGTH('a)"
   shows "drop (LENGTH('a) - n) (to_bl w) = replicate n False"
 proof -
   have "to_bl w = take (LENGTH('a) - n) (to_bl w) @ replicate n False"
     by (rule is_aligned_replicate) fact+
   then have "drop (LENGTH('a) - n) (to_bl w) = drop (LENGTH('a) - n) \<dots>" by simp
   also have "\<dots> = replicate n False" by simp
   finally show ?thesis .
 qed
 
 lemma less_is_drop_replicate:
   fixes x::"'a::len word"
   assumes lt: "x < 2 ^ n"
   shows   "to_bl x = replicate (LENGTH('a) - n) False @ drop (LENGTH('a) - n) (to_bl x)"
   by (metis assms bl_and_mask' less_mask_eq)
 
 lemma is_aligned_add_conv:
   fixes off::"'a::len word"
   assumes aligned: "is_aligned w n"
   and        offv: "off < 2 ^ n"
   shows    "to_bl (w + off) =
    (take (LENGTH('a) - n) (to_bl w)) @ (drop (LENGTH('a) - n) (to_bl off))"
 proof cases
   assume nv: "n \<le> LENGTH('a)"
   show ?thesis
   proof (subst aligned_bl_add_size, simp_all only: word_size)
     show "drop (LENGTH('a) - n) (to_bl w) = replicate n False"
       by (subst is_aligned_replicate [OF aligned nv]) (simp add: word_size)
 
     from offv show "take (LENGTH('a) - n) (to_bl off) =
                     replicate (LENGTH('a) - n) False"
       by (subst less_is_drop_replicate, assumption) simp
   qed fact
 next
   assume "\<not> n \<le> LENGTH('a)"
   with offv show ?thesis by (simp add: power_overflow)
 qed
 
 lemma is_aligned_replicateI:
   "to_bl p = addr @ replicate n False \<Longrightarrow> is_aligned (p::'a::len word) n"
   apply (simp add: is_aligned_to_bl word_size)
   apply (subgoal_tac "length addr = LENGTH('a) - n")
    apply (simp add: replicate_not_True)
   apply (drule arg_cong [where f=length])
   apply simp
   done
 
 lemma to_bl_2p:
   "n < LENGTH('a) \<Longrightarrow>
    to_bl ((2::'a::len word) ^ n) =
    replicate (LENGTH('a) - Suc n) False @ True # replicate n False"
   apply (subst shiftl_1 [symmetric])
   apply (subst bl_shiftl)
   apply (simp add: to_bl_1 min_def word_size)
   done
 
 lemma xor_2p_to_bl:
   fixes x::"'a::len word"
   shows "to_bl (x XOR 2^n) =
   (if n < LENGTH('a)
    then take (LENGTH('a)-Suc n) (to_bl x) @ (\<not>rev (to_bl x)!n) # drop (LENGTH('a)-n) (to_bl x)
    else to_bl x)"
   apply (auto simp add: to_bl_eq_rev take_map drop_map take_rev drop_rev bit_simps)
   apply (rule nth_equalityI)
    apply (auto simp add: bit_simps rev_nth nth_append Suc_diff_Suc)
   done
 
 lemma is_aligned_replicateD:
   "\<lbrakk> is_aligned (w::'a::len word) n; n \<le> LENGTH('a) \<rbrakk>
      \<Longrightarrow> \<exists>xs. to_bl w = xs @ replicate n False
                \<and> length xs = size w - n"
   apply (subst is_aligned_replicate, assumption+)
   apply (rule exI, rule conjI, rule refl)
   apply (simp add: word_size)
   done
 
 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 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 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) AND NOT(mask n) = a"
   apply (simp flip: push_bit_eq_mult subtract_mask(1) take_bit_eq_mask)
   apply (subst disjunctive_add)
    apply (auto simp add: bit_simps not_le not_less)
    apply (meson is_aligned_imp_not_bit is_aligned_weaken less_diff_conv2)
   apply (erule is_alignedE')
   apply (simp add: take_bit_push_bit)
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps)
   done
 
 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 (simp flip: push_bit_eq_mult take_bit_eq_mask add: shiftr_eq_drop_bit)
   apply (subst disjunctive_add)
    apply (auto simp add: bit_simps not_le not_less unsigned_or_eq unsigned_drop_bit_eq
      unsigned_push_bit_eq bin_to_bl_or simp flip: bin_to_bl_def)
    apply (meson is_aligned_imp_not_bit is_aligned_weaken less_diff_conv2)
   apply (erule is_alignedE')
   apply (rule nth_equalityI)
    apply (auto simp add: nth_bin_to_bl bit_simps rev_nth simp flip: bin_to_bl_def)
   done
 
 (* FIXME: move to Word distribution *)
 lemma bin_nth_minus_Bit0[simp]:
   "0 < n \<Longrightarrow> bit (numeral (num.Bit0 w) :: int) n = bit (numeral w :: int) (n - 1)"
   by (cases n; simp)
 
 lemma bin_nth_minus_Bit1[simp]:
   "0 < n \<Longrightarrow> bit (numeral (num.Bit1 w) :: int) n = bit (numeral w :: int) (n - 1)"
   by (cases n; simp)
 
 (* 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 map_bits_rev_to_bl:
   "map (bit x) [0..<size x] = rev (to_bl x)"
   by (auto simp: list_eq_iff_nth_eq test_bit_bl word_size)
 
 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 of_bl_max:
   "(of_bl xs :: 'a::len word) \<le> mask (length xs)"
 proof -
   define ys where \<open>ys = rev xs\<close>
   have \<open>take_bit (length ys) (horner_sum of_bool 2 ys :: 'a word) = horner_sum of_bool 2 ys\<close>
     by transfer (simp add: take_bit_horner_sum_bit_eq min_def)
   then have \<open>(of_bl (rev ys) :: 'a word) \<le> mask (length ys)\<close>
     by (simp only: of_bl_rev_eq less_eq_mask_iff_take_bit_eq_self)
   with ys_def show ?thesis
     by simp
 qed
 
 text\<open>Some auxiliaries for sign-shifting by the entire word length or more\<close>
 
 lemma sshiftr_clamp_pos:
   assumes
     "LENGTH('a) \<le> n"
     "0 \<le> sint x"
   shows "(x::'a::len word) >>> n = 0"
   apply (rule word_sint.Rep_eqD)
   apply (unfold sshiftr_div_2n Word.sint_0)
   apply (rule div_pos_pos_trivial)
   subgoal using assms(2) .
   apply (rule order.strict_trans[where b="2 ^ (LENGTH('a) - 1)"])
   using sint_lt assms(1) by auto
 
 lemma sshiftr_clamp_neg:
   assumes
     "LENGTH('a) \<le> n"
     "sint x < 0"
   shows "(x::'a::len word) >>> n = -1"
 proof -
   have *: "- (2 ^ n) < sint x"
     apply (rule order.strict_trans2[where b="- (2 ^ (LENGTH('a) - 1))"])
     using assms(1) sint_ge by auto
   show ?thesis
     apply (rule word_sint.Rep_eqD)
     apply (unfold sshiftr_div_2n Word.sint_n1)
     apply (subst div_minus_minus[symmetric])
     apply (rule div_pos_neg_trivial)
     subgoal using assms(2) by linarith
     using * by simp
 qed
 
 lemma sshiftr_clamp:
   assumes "LENGTH('a) \<le> n"
   shows "(x::'a::len word) >>> n = x >>> LENGTH('a)"
   apply (cases "0 \<le> sint x")
   subgoal
     apply (subst sshiftr_clamp_pos[OF assms])
     defer apply (subst sshiftr_clamp_pos)
     by auto
   apply (subst sshiftr_clamp_neg[OF assms])
   defer apply (subst sshiftr_clamp_neg)
   by auto
 
 text\<open>
 Like @{thm shiftr1_bl_of}, but the precondition is stronger because we need to pick the msb out of
 the list.
 \<close>
 lemma sshiftr1_bl_of:
   "length bl = LENGTH('a) \<Longrightarrow>
     sshiftr1 (of_bl bl::'a::len word) = of_bl (hd bl # butlast bl)"
   apply (rule word_bl.Rep_eqD)
   apply (subst bl_sshiftr1[of "of_bl bl :: 'a word"])
   by (simp add: word_bl.Abs_inverse)
 
 text\<open>
 Like @{thm sshiftr1_bl_of}, with a weaker precondition.
 We still get a direct equation for @{term \<open>sshiftr1 (of_bl bl)\<close>}, it's just uglier.
 \<close>
 lemma sshiftr1_bl_of':
   "LENGTH('a) \<le> length bl \<Longrightarrow>
     sshiftr1 (of_bl bl::'a::len word) =
     of_bl (hd (drop (length bl - LENGTH('a)) bl) # butlast (drop (length bl - LENGTH('a)) bl))"
   apply (subst of_bl_drop'[symmetric, of "length bl - LENGTH('a)"])
   using sshiftr1_bl_of[of "drop (length bl - LENGTH('a)) bl"]
   by auto
 
 text\<open>
 Like @{thm shiftr_bl_of}.
 \<close>
 lemma sshiftr_bl_of:
   assumes "length bl = LENGTH('a)"
   shows "(of_bl bl::'a::len word) >>> n = of_bl (replicate n (hd bl) @ take (length bl - n) bl)"
 proof -
   {
     fix n
     assume "n \<le> LENGTH('a)"
     hence "(of_bl bl::'a::len word) >>> n = of_bl (replicate n (hd bl) @ take (length bl - n) bl)"
     proof (induction n)
       case (Suc n)
       hence "n < length bl" by (simp add: assms)
       hence ne: "\<not>take (length bl - n) bl = []" by auto
       have left: "hd (replicate n (hd bl) @ take (length bl - n) bl) = (hd bl)"
         by (cases "0 < n") auto
       have right: "butlast (take (length bl - n) bl) = take (length bl - Suc n) bl"
         by (subst butlast_take) auto
       have "(of_bl bl::'a::len word) >>> Suc n = sshiftr1 ((of_bl bl::'a::len word) >>> n)"
         unfolding sshiftr_eq_funpow_sshiftr1 by simp
       also have "\<dots> = of_bl (replicate (Suc n) (hd bl) @ take (length bl - Suc n) bl)"
         apply (subst Suc.IH[OF Suc_leD[OF Suc.prems]])
         apply (subst sshiftr1_bl_of)
         subgoal using assms Suc.prems by simp
         apply (rule arg_cong[where f=of_bl])
         apply (subst butlast_append)
         unfolding left right using ne by simp
       finally show ?case .
     qed (transfer, simp)
   }
   note pos = this
   {
     assume n: "LENGTH('a) \<le> n"
     have "(of_bl bl::'a::len word) >>> n = (of_bl bl::'a::len word) >>> LENGTH('a)"
       by (rule sshiftr_clamp[OF n])
     also have "\<dots> = of_bl (replicate LENGTH('a) (hd bl) @ take (length bl - LENGTH('a)) bl)"
       apply (rule pos) ..
     also have "\<dots> = of_bl (replicate n (hd bl) @ take (length bl - n) bl)"
     proof -
       have "(of_bl (replicate LENGTH('a) (hd bl)) :: 'a word) = of_bl (replicate n (hd bl))"
         apply (subst of_bl_drop'[symmetric, of "n - LENGTH('a)" "replicate n (hd bl)"])
         unfolding length_replicate by (auto simp: n)
       thus ?thesis by (simp add: assms n)
     qed
     finally have "(of_bl bl::'a::len word) >>> n
       = of_bl (replicate n (hd bl) @ take (length bl - n) bl)" .
   }
   thus ?thesis using pos by fastforce
 qed
 
 text\<open>Like @{thm shiftr_bl}\<close>
 lemma sshiftr_bl: "x >>> n \<equiv> of_bl (replicate n (msb x) @ take (LENGTH('a) - n) (to_bl x))"
   for x :: "'a::len word"
   unfolding word_msb_alt
   by (smt (z3) length_to_bl_eq sshiftr_bl_of word_bl.Rep_inverse)
 
 end
diff --git a/thys/Word_Lib/Traditional_Infix_Syntax.thy b/thys/Word_Lib/Traditional_Infix_Syntax.thy
--- a/thys/Word_Lib/Traditional_Infix_Syntax.thy
+++ b/thys/Word_Lib/Traditional_Infix_Syntax.thy
@@ -1,840 +1,820 @@
 (*
  * Copyright Data61, CSIRO (ABN 41 687 119 230)
  *
  * SPDX-License-Identifier: BSD-2-Clause
  *)
 
 (* Author: Jeremy Dawson, NICTA *)
 
 section \<open>Operation variants with traditional syntax\<close>
 
 theory Traditional_Infix_Syntax
   imports "HOL-Library.Word" More_Word Signed_Words Syntax_Bundles
 begin
 
 class semiring_bit_syntax = semiring_bit_shifts
 begin
 
 definition shiftl :: \<open>'a \<Rightarrow> nat \<Rightarrow> 'a\<close>  (infixl "<<" 55)
   where shiftl_eq_push_bit: \<open>a << n = push_bit n a\<close>
 
 definition shiftr :: \<open>'a \<Rightarrow> nat \<Rightarrow> 'a\<close>  (infixl ">>" 55)
   where shiftr_eq_drop_bit: \<open>a >> n = drop_bit n a\<close>
 
 end
 
 instance word :: (len) semiring_bit_syntax ..
 
 context
   includes lifting_syntax
 begin
 
 lemma shiftl_word_transfer [transfer_rule]:
   \<open>(pcr_word ===> (=) ===> pcr_word) (\<lambda>k n. push_bit n k) shiftl\<close>
   by (unfold shiftl_eq_push_bit) transfer_prover
 
 lemma shiftr_word_transfer [transfer_rule]:
   \<open>(pcr_word ===> (=) ===> pcr_word) (\<lambda>k n. (drop_bit n \<circ> take_bit LENGTH('a)) k) (shiftr :: 'a::len word \<Rightarrow> _)\<close>
   by (unfold shiftr_eq_drop_bit) transfer_prover
 
 end
 
 lemma shiftl_word_eq:
   \<open>w << n = push_bit n w\<close> for w :: \<open>'a::len word\<close>
   by (fact shiftl_eq_push_bit)
 
 lemma shiftr_word_eq:
   \<open>w >> n = drop_bit n w\<close> for w :: \<open>'a::len word\<close>
   by (fact shiftr_eq_drop_bit)
 
-lemma shiftl1_code [code]:
-  \<open>shiftl1 w = push_bit 1 w\<close>
-  by transfer (simp add: ac_simps)
-
 lemma uint_shiftr_eq:
   \<open>uint (w >> n) = uint w div 2 ^ n\<close>
   by transfer (simp flip: drop_bit_eq_div add: drop_bit_take_bit min_def le_less less_diff_conv)
 
-lemma shiftr1_code [code]:
-  \<open>shiftr1 w = drop_bit 1 w\<close>
-  by transfer (simp add: drop_bit_Suc)
+lemma bit_shiftl_word_iff [bit_simps]:
+  \<open>bit (w << m) n \<longleftrightarrow> m \<le> n \<and> n < LENGTH('a) \<and> bit w (n - m)\<close>
+  for w :: \<open>'a::len word\<close>
+  by (simp add: shiftl_word_eq bit_push_bit_iff not_le)
 
 lemma shiftl_def:
-  \<open>w << n = (shiftl1 ^^ n) w\<close>
+  \<open>w << n = ((*) 2 ^^ n) w\<close> for w :: \<open>'a::len word\<close>
 proof -
   have \<open>push_bit n = (((*) 2 ^^ n) :: int \<Rightarrow> int)\<close> for n
     by (induction n) (simp_all add: fun_eq_iff funpow_swap1, simp add: ac_simps)
   then show ?thesis
     by transfer simp
 qed
 
 lemma shiftr_def:
-  \<open>w >> n = (shiftr1 ^^ n) w\<close>
+  \<open>w >> n = ((\<lambda>w. w div 2) ^^ n) w\<close> for w :: \<open>'a::len word\<close>
 proof -
-  have \<open>shiftr1 ^^ n = (drop_bit n :: 'a word \<Rightarrow> 'a word)\<close>
-    apply (induction n)
-    apply simp
-    apply (simp only: shiftr1_eq_div_2 [abs_def] drop_bit_eq_div [abs_def] funpow_Suc_right)
-    apply (use div_exp_eq [of _ 1, where ?'a = \<open>'a word\<close>] in simp)
-    done
+  have \<open>(\<lambda>w. w div 2) ^^ n = (drop_bit n :: 'a word \<Rightarrow> 'a word)\<close>
+    by (induction n) (simp_all add: drop_bit_half drop_bit_Suc)
   then show ?thesis
     by (simp add: shiftr_eq_drop_bit)
 qed
 
-lemma bit_shiftl_word_iff [bit_simps]:
-  \<open>bit (w << m) n \<longleftrightarrow> m \<le> n \<and> n < LENGTH('a) \<and> bit w (n - m)\<close>
-  for w :: \<open>'a::len word\<close>
-  by (simp add: shiftl_word_eq bit_push_bit_iff not_le)
-
 lemma bit_shiftr_word_iff [bit_simps]:
   \<open>bit (w >> m) n \<longleftrightarrow> bit w (m + n)\<close>
   for w :: \<open>'a::len word\<close>
   by (simp add: shiftr_word_eq bit_drop_bit_eq)
 
 lift_definition sshiftr :: \<open>'a::len word \<Rightarrow> nat \<Rightarrow> 'a word\<close>  (infixl \<open>>>>\<close> 55)
   is \<open>\<lambda>k n. take_bit LENGTH('a) (drop_bit n (signed_take_bit (LENGTH('a) - Suc 0) k))\<close>
   by (simp flip: signed_take_bit_decr_length_iff)
 
 lemma sshiftr_eq [code]:
   \<open>w >>> n = signed_drop_bit n w\<close>
   by transfer simp
 
 lemma sshiftr_eq_funpow_sshiftr1:
-  \<open>w >>> n = (sshiftr1 ^^ n) w\<close>
+  \<open>w >>> n = (signed_drop_bit (Suc 0) ^^ n) w\<close>
   apply (rule sym)
-  apply (simp add: sshiftr1_eq_signed_drop_bit_Suc_0 sshiftr_eq)
+  apply (simp add: sshiftr_eq)
   apply (induction n)
    apply simp_all
   done
 
 lemma uint_sshiftr_eq:
   \<open>uint (w >>> n) = take_bit LENGTH('a) (sint w div 2 ^  n)\<close>
   for w :: \<open>'a::len word\<close>
   by transfer (simp flip: drop_bit_eq_div)
 
-lemma sshift1_code [code]:
-  \<open>sshiftr1 w = signed_drop_bit 1 w\<close>
-  by transfer (simp add: drop_bit_Suc)
-
 lemma sshiftr_0 [simp]: "0 >>> n = 0"
   by transfer simp
 
 lemma sshiftr_n1 [simp]: "-1 >>> n = -1"
   by transfer simp
 
 lemma bit_sshiftr_word_iff [bit_simps]:
   \<open>bit (w >>> m) n \<longleftrightarrow> bit w (if LENGTH('a) - m \<le> n \<and> n < LENGTH('a) then LENGTH('a) - 1 else (m + n))\<close>
   for w :: \<open>'a::len word\<close>
   apply transfer
   apply (auto simp add: bit_take_bit_iff bit_drop_bit_eq bit_signed_take_bit_iff min_def not_le simp flip: bit_Suc)
   using le_less_Suc_eq apply fastforce
   using le_less_Suc_eq apply fastforce
   done
 
 lemma nth_sshiftr :
   "bit (w >>> m) n =
     (n < size w \<and> (if n + m \<ge> size w then bit w (size w - 1) else bit w (n + m)))"
   apply transfer
   apply (auto simp add: bit_take_bit_iff bit_drop_bit_eq bit_signed_take_bit_iff min_def not_le ac_simps)
   using le_less_Suc_eq apply fastforce
   using le_less_Suc_eq apply fastforce
   done
 
 lemma sshiftr_numeral [simp]:
   \<open>(numeral k >>> numeral n :: 'a::len word) =
     word_of_int (drop_bit (numeral n) (signed_take_bit (LENGTH('a) - 1) (numeral k)))\<close>
   apply (rule bit_word_eqI)
    apply (simp add: word_size nth_sshiftr ac_simps bit_simps)
   done
 
 setup \<open>
   Context.theory_map (fold SMT_Word.add_word_shift' [
     (\<^term>\<open>shiftl :: 'a::len word \<Rightarrow> _\<close>, "bvshl"),
     (\<^term>\<open>shiftr :: 'a::len word \<Rightarrow> _\<close>, "bvlshr"),
     (\<^term>\<open>sshiftr :: 'a::len word \<Rightarrow> _\<close>, "bvashr")
   ])
 \<close>
 
 lemma revcast_down_us [OF refl]:
   "rc = revcast \<Longrightarrow> source_size rc = target_size rc + n \<Longrightarrow> rc w = ucast (w >>> n)"
   for w :: "'a::len word"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_ucast_iff bit_sshiftr_word_iff ac_simps)
   done
 
 lemma revcast_down_ss [OF refl]:
   "rc = revcast \<Longrightarrow> source_size rc = target_size rc + n \<Longrightarrow> rc w = scast (w >>> n)"
   for w :: "'a::len word"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_word_scast_iff bit_sshiftr_word_iff ac_simps)
   done
 
 lemma sshiftr_div_2n: "sint (w >>> n) = sint w div 2 ^ n"
   using sint_signed_drop_bit_eq [of n w]
   by (simp add: drop_bit_eq_div sshiftr_eq)
 
 lemma mask_eq:
   \<open>mask n = (1 << n) - (1 :: 'a::len word)\<close>
   by transfer (simp add: mask_eq_exp_minus_1 push_bit_of_1)
 
 lemma shiftl_0 [simp]: "(0::'a::len word) << n = 0"
   by transfer simp
 
 lemma shiftr_0 [simp]: "(0::'a::len word) >> n = 0"
   by transfer simp
 
 lemma nth_shiftl': "bit (w << m) n \<longleftrightarrow> n < size w \<and> n >= m \<and> bit w (n - m)"
   for w :: "'a::len word"
   by transfer (auto simp add: bit_push_bit_iff)
 
 lemmas nth_shiftl = nth_shiftl' [unfolded word_size]
 
 lemma nth_shiftr: "bit (w >> m) n = bit w (n + m)"
   for w :: "'a::len word"
-  apply (unfold shiftr_def)
-  apply (induct "m" arbitrary: n)
-   apply (auto simp add: nth_shiftr1)
-  done
+  by (simp add: bit_simps ac_simps)
 
 lemma shiftr_div_2n: "uint (shiftr w n) = uint w div 2 ^ n"
   by (fact uint_shiftr_eq)
 
 lemma shiftl_rev: "shiftl w n = word_reverse (shiftr (word_reverse w) n)"
-  by (induct n) (auto simp add: shiftl_def shiftr_def shiftl1_rev)
+  by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma rev_shiftl: "word_reverse w << n = word_reverse (w >> n)"
   by (simp add: shiftl_rev)
 
 lemma shiftr_rev: "w >> n = word_reverse (word_reverse w << n)"
   by (simp add: rev_shiftl)
 
 lemma rev_shiftr: "word_reverse w >> n = word_reverse (w << n)"
   by (simp add: shiftr_rev)
 
 lemma shiftl_numeral [simp]:
   \<open>numeral k << numeral l = (push_bit (numeral l) (numeral k) :: 'a::len word)\<close>
   by (fact shiftl_word_eq)
 
 lemma shiftl_zero_size: "size x \<le> n \<Longrightarrow> x << n = 0"
   for x :: "'a::len word"
   apply transfer
   apply (simp add: take_bit_push_bit)
   done
 
 lemma shiftl_t2n: "shiftl w n = 2 ^ n * w"
   for w :: "'a::len word"
-  by (induct n) (auto simp: shiftl_def shiftl1_2t)
+  by (simp add: shiftl_eq_push_bit push_bit_eq_mult)
 
 lemma shiftr_numeral [simp]:
   \<open>(numeral k >> numeral n :: 'a::len word) = drop_bit (numeral n) (numeral k)\<close>
   by (fact shiftr_word_eq)
 
 lemma shiftr_numeral_Suc [simp]:
   \<open>(numeral k >> Suc 0 :: 'a::len word) = drop_bit (Suc 0) (numeral k)\<close>
   by (fact shiftr_word_eq)
 
 lemma slice_shiftr: "slice n w = ucast (w >> n)"
   apply (rule bit_word_eqI)
   apply (cases \<open>n \<le> LENGTH('b)\<close>)
    apply (auto simp add: bit_slice_iff bit_ucast_iff bit_shiftr_word_iff ac_simps
     dest: bit_imp_le_length)
   done
 
 lemma revcast_down_uu [OF refl]:
   "rc = revcast \<Longrightarrow> source_size rc = target_size rc + n \<Longrightarrow> rc w = ucast (w >> n)"
   for w :: "'a::len word"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_ucast_iff bit_shiftr_word_iff ac_simps)
   done
 
 lemma revcast_down_su [OF refl]:
   "rc = revcast \<Longrightarrow> source_size rc = target_size rc + n \<Longrightarrow> rc w = scast (w >> n)"
   for w :: "'a::len word"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_word_scast_iff bit_shiftr_word_iff ac_simps)
   done
 
 lemma cast_down_rev [OF refl]:
   "uc = ucast \<Longrightarrow> source_size uc = target_size uc + n \<Longrightarrow> uc w = revcast (w << n)"
   for w :: "'a::len word"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_word_ucast_iff bit_shiftl_word_iff)
   done
 
 lemma revcast_up [OF refl]:
   "rc = revcast \<Longrightarrow> source_size rc + n = target_size rc \<Longrightarrow>
     rc w = (ucast w :: 'a::len word) << n"
   apply (simp add: source_size_def target_size_def)
   apply (rule bit_word_eqI)
   apply (simp add: bit_revcast_iff bit_word_ucast_iff bit_shiftl_word_iff)
   apply auto
   apply (metis add.commute add_diff_cancel_right)
   apply (metis diff_add_inverse2 diff_diff_add)
   done
 
 lemmas rc1 = revcast_up [THEN
   revcast_rev_ucast [symmetric, THEN trans, THEN word_rev_gal, symmetric]]
 lemmas rc2 = revcast_down_uu [THEN
   revcast_rev_ucast [symmetric, THEN trans, THEN word_rev_gal, symmetric]]
 
 lemmas ucast_up =
   rc1 [simplified rev_shiftr [symmetric] revcast_ucast [symmetric]]
 lemmas ucast_down =
   rc2 [simplified rev_shiftr revcast_ucast [symmetric]]
 
 \<comment> \<open>problem posed by TPHOLs referee:
       criterion for overflow of addition of signed integers\<close>
 
 lemma sofl_test:
   \<open>sint x + sint y = sint (x + y) \<longleftrightarrow>
     (x + y XOR x) AND (x + y XOR y) >> (size x - 1) = 0\<close>
   for x y :: \<open>'a::len word\<close>
 proof -
   obtain n where n: \<open>LENGTH('a) = Suc n\<close>
     by (cases \<open>LENGTH('a)\<close>) simp_all
   have *: \<open>sint x + sint y + 2 ^ Suc n > signed_take_bit n (sint x + sint y) \<Longrightarrow> sint x + sint y \<ge> - (2 ^ n)\<close>
     \<open>signed_take_bit n (sint x + sint y) > sint x + sint y - 2 ^ Suc n \<Longrightarrow> 2 ^ n > sint x + sint y\<close>
     using signed_take_bit_int_greater_eq [of \<open>sint x + sint y\<close> n] signed_take_bit_int_less_eq [of n \<open>sint x + sint y\<close>]
     by (auto intro: ccontr)
   have \<open>sint x + sint y = sint (x + y) \<longleftrightarrow>
     (sint (x + y) < 0 \<longleftrightarrow> sint x < 0) \<or>
     (sint (x + y) < 0 \<longleftrightarrow> sint y < 0)\<close>
     using sint_less [of x] sint_greater_eq [of x] sint_less [of y] sint_greater_eq [of y]
     signed_take_bit_int_eq_self [of \<open>LENGTH('a) - 1\<close> \<open>sint x + sint y\<close>]
     apply (auto simp add: not_less)
        apply (unfold sint_word_ariths)
        apply (subst signed_take_bit_int_eq_self)
          prefer 4
          apply (subst signed_take_bit_int_eq_self)
            prefer 7
            apply (subst signed_take_bit_int_eq_self)
              prefer 10
              apply (subst signed_take_bit_int_eq_self)
                apply (auto simp add: signed_take_bit_int_eq_self signed_take_bit_eq_take_bit_minus take_bit_Suc_from_most n not_less intro!: *)
        apply (smt (z3) take_bit_nonnegative)
       apply (smt (z3) take_bit_int_less_exp)
      apply (smt (z3) take_bit_nonnegative)
     apply (smt (z3) take_bit_int_less_exp)
     done
   then show ?thesis
     apply (simp only: One_nat_def word_size shiftr_word_eq drop_bit_eq_zero_iff_not_bit_last bit_and_iff bit_xor_iff)
     apply (simp add: bit_last_iff)
     done
 qed
 
 lemma shiftr_zero_size: "size x \<le> n \<Longrightarrow> x >> n = 0"
   for x :: "'a :: len word"
   by (rule word_eqI) (auto simp add: nth_shiftr dest: test_bit_size)
 
 lemma shiftr_x_0 [iff]: "x >> 0 = x"
   for x :: "'a::len word"
   by transfer simp
 
 lemma shiftl_x_0 [simp]: "x << 0 = x"
   for x :: "'a::len word"
   by (simp add: shiftl_t2n)
 
 lemma shiftl_1 [simp]: "(1::'a::len word) << n = 2^n"
   by (simp add: shiftl_t2n)
 
 lemma shiftr_1[simp]: "(1::'a::len word) >> n = (if n = 0 then 1 else 0)"
   by (induct n) (auto simp: shiftr_def)
 
 lemma shiftl0:
   "x << 0 = (x :: 'a :: len word)"
   by (fact shiftl_x_0)
 
 lemma word_ops_nth:
   fixes x y :: \<open>'a::len word\<close>
   shows
   word_or_nth:  "bit (x OR y) n = (bit x n \<or> bit y n)" and
   word_and_nth: "bit (x AND y) n = (bit x n \<and> bit y n)" and
   word_xor_nth: "bit (x XOR y) n = (bit x n \<noteq> bit y n)"
   by (simp_all add: bit_simps)
 
 lemma and_not_mask:
   "w AND NOT (mask n) = (w >> n) << n"
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma and_mask:
   "w AND mask n = (w << (size w - n)) >> (size w - n)"
   for w :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps word_size)
 
 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 (metis uint_shiftr_eq word_of_int_uint)
   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)
+  apply transfer
+  apply (simp add: take_bit_drop_bit)
+  apply (simp add: drop_bit_eq_div zdiv_mono1)
   done
 
 lemma shiftr_mask_le:
   "n <= m \<Longrightarrow> mask n >> m = (0 :: 'a::len word)"
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma shiftr_mask [simp]:
   \<open>mask m >> m = (0::'a::len word)\<close>
   by (rule shiftr_mask_le) simp
 
 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 xtrans(3))
     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 bit_simps)
   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 transfer
   apply (auto simp add: fun_eq_iff bit_simps)
   apply (metis add_diff_inverse_nat)
   done
 
 lemma mask_shiftl_decompose:
   "mask m << n = mask (m + n) AND NOT (mask n :: 'a::len word)"
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 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 bit_simps)
   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 bit_simps)
   done
 
 lemma shiftr_shiftl1:
   fixes a::"'a::len word"
   shows "c \<le> b \<Longrightarrow> a >> b << c = (a >> (b - c)) AND (NOT (mask c))"
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 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 bit_simps)
   done
 
 lemmas multi_shift_simps =
   shiftl_shiftl shiftr_shiftr
   shiftl_shiftr1 shiftl_shiftr2
   shiftr_shiftl1 shiftr_shiftl2
 
 lemma shiftr_mask2:
   "n \<le> LENGTH('a) \<Longrightarrow> (mask n >> m :: ('a :: len) word) = mask (n - m)"
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 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 mask_shift:
   "(x AND NOT (mask y)) >> y = x >> y"
   for x :: \<open>'a::len word\<close>
   apply (rule bit_eqI)
   apply (simp add: bit_and_iff bit_not_iff bit_shiftr_word_iff bit_mask_iff not_le)
   using bit_imp_le_length apply auto
   done
 
 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_eq_unatI)
   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 transfer (simp add: take_bit_push_bit)
 
 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_shiftr_lt:
   fixes w :: "'a::len word"
   shows "unat (w >> n) < (2 ^ (LENGTH('a) - n))"
   apply (subst shiftr_div_2n')
   apply transfer
   apply (simp flip: drop_bit_eq_div add: drop_bit_nat_eq drop_bit_take_bit)
   done
 
 lemma shiftr_less_t2n':
   "\<lbrakk> x AND 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] flip: take_bit_eq_mask)
   apply transfer
   apply (simp add: take_bit_drop_bit ac_simps)
   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 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] flip: take_bit_eq_mask)
   apply transfer
   apply (simp add: take_bit_push_bit)
   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 scast_bit_test [simp]:
     "scast ((1 :: 'a::len signed word) << n) = (1 :: 'a word) << n"
   by (clarsimp simp: word_eq_iff)
 
 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 shiftr_not_mask_0:
   "n+m \<ge> LENGTH('a :: len) \<Longrightarrow> ((w::'a::len word) >> n) AND NOT (mask m) = 0"
   by (rule bit_word_eqI) (auto simp add: bit_simps word_size dest: bit_imp_le_length)
 
 lemma shiftl_mask_is_0[simp]:
   "(x << n) AND mask n = 0"
   for x :: \<open>'a::len word\<close>
   by (simp flip: take_bit_eq_mask add: shiftl_eq_push_bit take_bit_push_bit)
 
 lemma rshift_sub_mask_eq:
   "(a >> (size a - b)) AND mask b = a >> (size a - b)"
   for a :: \<open>'a::len word\<close>
   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) AND mask (size a - c)"
   for a :: \<open>'a::len word\<close>
   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 AND mask m) >> n = (w >> n) AND mask (m-n)"
   for w :: \<open>'a::len word\<close>
   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 AND mask m) << n = (w << n) AND mask (m+n)"
   for w :: \<open>'a::len word\<close>
   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 word_and_1_shiftl:
   "x AND (1 << n) = (if bit x n then (1 << n) else 0)" for x :: "'a :: len word"
   apply (rule bit_word_eqI; transfer)
   apply (auto simp add: bit_simps not_le ac_simps)
   done
 
 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 AND (mask n << m) = ((x >> m) AND mask n) << m"
   for x :: \<open>'a::len word\<close>
   apply (rule bit_word_eqI; transfer)
   apply (auto simp add: bit_simps not_le ac_simps)
   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 of_bool_nth:
   "of_bool (bit x v) = (x >> v) AND 1"
   for x :: \<open>'a::len word\<close>
   by (simp add: bit_iff_odd_drop_bit shiftr_word_eq word_and_1)
 
 lemma shiftr_mask_eq:
   "(x >> n) AND mask (size x - n) = x >> n" for x :: "'a :: len word"
   apply (simp flip: take_bit_eq_mask)
   apply transfer
   apply (simp add: take_bit_drop_bit)
   done
 
 lemma shiftr_mask_eq':
   "m = (size x - n) \<Longrightarrow> (x >> n) AND mask m = x >> n" for x :: "'a :: len word"
   by (simp add: shiftr_mask_eq)
 
 lemma and_eq_0_is_nth:
   fixes x :: "'a :: len word"
   shows "y = 1 << n \<Longrightarrow> ((x AND y) = 0) = (\<not> (bit x n))"
   by (simp add: and_exp_eq_0_iff_not_bit)
 
 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 mask_shift_and_negate[simp]:"(w AND mask n << m) AND NOT (mask n << m) = 0"
   for w :: \<open>'a::len word\<close>
   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)
 
 (* 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 AND NOT (mask n << m) OR ((y AND mask n) << m)) AND NOT (mask n << m) = x AND NOT (mask n << m)"
   for x :: \<open>'a::len word\<close>
   by (induct n arbitrary: m) (auto simp: word_ao_dist)
 
 lemma bitfield_op_twice'':
   "\<lbrakk>NOT a = b << c; \<exists>x. b = mask x\<rbrakk> \<Longrightarrow> (x AND a OR (y AND b << c)) AND a = x AND a"
   for a b :: \<open>'a::len word\<close>
   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 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_unfold: "x div 2 = x >> 1"
+  by (simp add: drop_bit_eq_div shiftr_eq_drop_bit)
 
 lemma shiftr1_is_div_2: "(x::('a::len) word) >> 1 = x div 2"
-  by transfer (simp add: drop_bit_Suc)
+  by (simp add: drop_bit_eq_div shiftr_eq_drop_bit)
 
 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 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 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 shiftr1_irrelevant_lsb: "bit (x::('a::len) word) 0 \<or> x >> 1 = (x + 1) >> 1"
   apply (cases \<open>LENGTH('a)\<close>; transfer)
    apply (simp_all add: take_bit_drop_bit)
   apply (simp add: drop_bit_take_bit drop_bit_Suc)
   done
 
 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> (bit (x::('a::len) word) 0) \<Longrightarrow> x >> 1 = (x + 1) >> 1"
   by (metis shiftr1_irrelevant_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) OR (((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) OR
    (((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
 
 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
@@ -1,1696 +1,1689 @@
 (*
  * 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
     Type_Syntax
     Signed_Division_Word
     Signed_Words
     More_Word
     Most_significant_bit
     Enumeration_Word
     Aligned
 begin
 
 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)
     apply (metis \<open>x \<le> 2 ^ LENGTH('b) - 1\<close> and_mask_eq_iff_le_mask mask_eq_decr_exp take_bit_eq_mask)
     done
 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 complement_nth_w2p:
   shows "n' < LENGTH('a) \<Longrightarrow> bit (NOT (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 AND 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) AND 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 less_mult_imp_div_less)
 
 lemma le_or_mask:
   "w \<le> w' \<Longrightarrow> w OR mask x \<le> w' OR mask x"
   for w w' :: \<open>'a::len word\<close>
   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')
+  apply (simp add: shiftr_eq_drop_bit)
+  apply (metis le_cases le_shiftr shiftr_word_eq verit_la_disequality)
   done
 
 lemma word_add_no_overflow:"(x::'a::len word) < - 1 \<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]
 
 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) AND NOT (mask n) = 0"
   by (simp add: and_not_mask shiftr_eq_0)
 
 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> bit 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> bit (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_diff_power_eq)
   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 (meson nat_mult_power_less_eq zero_less_numeral)
     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)
   apply transfer
   apply (auto simp add: is_aligned_iff_udvd)
   apply (metis bintrunc_bintrunc_ge int_ops(1) nat_int_comparison(1) nat_less_le take_bit_eq_0_iff take_bit_nat_eq_self_iff take_bit_of_nat)
   done
 
 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:
   "(- 1 :: 'a::len word) = mask LENGTH('a)"
   by (fact minus_1_eq_mask)
 
 lemmas mask_len_max = max_word_mask[symmetric]
 
 lemma mask_out_first_mask_some:
   "\<lbrakk> x AND NOT (mask n) = y; n \<le> m \<rbrakk> \<Longrightarrow> x AND NOT (mask m) = y AND NOT (mask m)"
   for x y :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps word_size)
 
 lemma mask_lower_twice:
   "n \<le> m \<Longrightarrow> (x AND NOT (mask n)) AND NOT (mask m) = x AND NOT (mask m)"
   for x :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps word_size)
 
 lemma mask_lower_twice2:
   "(a AND NOT (mask n)) AND NOT (mask m) = a AND NOT (mask (max n m))"
   for a :: \<open>'a::len word\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma ucast_and_neg_mask:
   "ucast (x AND NOT (mask n)) = ucast x AND NOT (mask n)"
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps dest: bit_imp_le_length)
   done
 
 lemma ucast_and_mask:
   "ucast (x AND mask n) = ucast x AND mask n"
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps dest: bit_imp_le_length)
   done
 
 lemma ucast_mask_drop:
   "LENGTH('a :: len) \<le> n \<Longrightarrow> (ucast (x AND mask n) :: 'a word) = ucast x"
   apply (rule bit_word_eqI)
   apply (auto simp add: bit_simps dest: bit_imp_le_length)
   done
 
 (* negating a mask which has been shifted to the very left *)
 lemma NOT_mask_shifted_lenword:
   "NOT (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 transfer simp
 
 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 ucast_or_distrib:
   fixes x :: "'a::len word"
   fixes y :: "'a::len word"
   shows "(ucast (x OR y) :: ('b::len) word) = ucast x OR 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 AND w' \<noteq> 0 \<Longrightarrow> w \<noteq> 0 \<and> w' \<noteq> 0"
   by auto
 
 lemma word_exists_nth:
   "(w::'a::len word) \<noteq> 0 \<Longrightarrow> \<exists>i. bit w i"
   by (simp add: bit_eq_iff)
 
 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:
   \<open>is_aligned w n\<close> if \<open>UCAST('a::len \<rightarrow> 'b::len) w = 0\<close> \<open>n \<le> LENGTH('b)\<close>
 proof (rule is_aligned_bitI)
   fix q
   assume \<open>q < n\<close>
   moreover have \<open>bit (UCAST('a::len \<rightarrow> 'b::len) w) q = bit 0 q\<close>
     using that by simp
   with \<open>q < n\<close> \<open>n \<le> LENGTH('b)\<close> show \<open>\<not> bit w q\<close>
     by (simp add: bit_simps)
 qed
 
 lemma unat_ucast_eq_unat_and_mask:
   "unat (UCAST('b::len \<rightarrow> 'a::len) w) = unat (w AND mask LENGTH('a))"
   apply (simp flip: take_bit_eq_mask)
   apply transfer
   apply (simp add: ac_simps)
   done
 
 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 (rule bit_word_eqI)
   fix q
   assume \<open>q < LENGTH('a)\<close>
   from eq have \<open>push_bit n x = push_bit n y\<close>
     by (simp add: push_bit_eq_mult)
   moreover from le have \<open>take_bit m x = x\<close> \<open>take_bit m y = y\<close>
     by (simp_all add: less_eq_mask_iff_take_bit_eq_self)
   ultimately have \<open>push_bit n (take_bit m x) = push_bit n (take_bit m y)\<close>
     by simp_all
   with \<open>q < LENGTH('a)\<close> ws show \<open>bit x q \<longleftrightarrow> bit y q\<close>
     apply (simp add: push_bit_take_bit)
     unfolding bit_eq_iff
     apply (simp add: bit_simps not_le)
     apply (metis (full_types) \<open>take_bit m x = x\<close> \<open>take_bit m y = y\<close> add.commute add_diff_cancel_right' add_less_cancel_right bit_take_bit_iff le_add2 less_le_trans)
     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])
 
 (* 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)
   apply (meson less_irrefl not_le zero_le_numeral zero_le_power)
   done
 
 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>concat_bit n b a \<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: "concat_bit n b a = concat_bit m d c"
   if "n = m" "a = c" "take_bit m b = take_bit m d"
   using that(3) unfolding that(1,2) by (simp add: bin_cat_eq_push_bit_add_take_bit)
 
 lemma bin_cat_eqD1: "concat_bit n b a = concat_bit n d c \<Longrightarrow> a = c"
   by (metis drop_bit_bin_cat_eq)
 
 lemma bin_cat_eqD2: "concat_bit n b a = concat_bit n d c \<Longrightarrow> take_bit n b = take_bit n d"
   by (metis take_bit_bin_cat_eq)
 
 lemma bin_cat_inj: "(concat_bit n b a) = concat_bit n d c \<longleftrightarrow> a = c \<and> take_bit n b = take_bit 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 (concat_bit LENGTH('b) (uint b) (uint a))::'c::len word) =
   word_of_int (concat_bit LENGTH('b) (uint d) (uint c)) \<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 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_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 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 AND b = 0"
   by (metis and_zero_eq is_aligned_mask le_mask_imp_and_mask word_bw_lcs(1))
 
 lemma word_and_or_mask_aligned:
   "\<lbrakk> is_aligned a n; b \<le> mask n \<rbrakk> \<Longrightarrow> a + b = a OR 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 OR 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"
   apply transfer
   apply (auto simp add: min_def)
   apply (metis bintrunc_bintrunc_ge bintrunc_n_0 nat_less_le not_le take_bit_eq_0_iff)
   done
 
 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"
   apply (simp add: less_eq_mask_iff_take_bit_eq_self)
   apply transfer
   apply (simp add: ac_simps)
   done
 
 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:
   \<open>p' = p \<and> off' = off\<close>
   if *: \<open>p + (UCAST('a::len \<rightarrow> 'b::len) off << n) = p' + (ucast off' << n)\<close>
     and \<open>is_aligned p n'\<close> \<open>is_aligned p' n'\<close> \<open>n' = n + LENGTH('a)\<close> \<open>n' < LENGTH('b)\<close>
 proof -
   from \<open>n' = n + LENGTH('a)\<close>
   have [simp]: \<open>n' - n = LENGTH('a)\<close> \<open>n + LENGTH('a) = n'\<close>
     by simp_all
   from \<open>is_aligned p n'\<close> obtain q
     where p: \<open>p = push_bit n' (word_of_nat q)\<close> \<open>q < 2 ^ (LENGTH('b) - n')\<close>
     by (rule is_alignedE')
   from \<open>is_aligned p' n'\<close> obtain q'
     where p': \<open>p' = push_bit n' (word_of_nat q')\<close> \<open>q' < 2 ^ (LENGTH('b) - n')\<close>
     by (rule is_alignedE')
   define m :: nat where \<open>m = unat off\<close>
   then have off: \<open>off = word_of_nat m\<close>
     by simp
   define m' :: nat where \<open>m' = unat off'\<close>
   then have off': \<open>off' = word_of_nat m'\<close>
     by simp
   have \<open>push_bit n' q + take_bit n' (push_bit n m) < 2 ^ LENGTH('b)\<close>
     by (metis id_apply is_aligned_no_wrap''' of_nat_eq_id of_nat_push_bit p(1) p(2) take_bit_nat_eq_self_iff take_bit_nat_less_exp take_bit_push_bit that(2) that(5) unsigned_of_nat)
   moreover have \<open>push_bit n' q' + take_bit n' (push_bit n m') < 2 ^ LENGTH('b)\<close>
     by (metis \<open>n' - n = LENGTH('a)\<close> id_apply is_aligned_no_wrap''' m'_def of_nat_eq_id of_nat_push_bit off' p'(1) p'(2) take_bit_nat_eq_self_iff take_bit_push_bit that(3) that(5) unsigned_of_nat)
   ultimately have \<open>push_bit n' q + take_bit n' (push_bit n m) = push_bit n' q' + take_bit n' (push_bit n m')\<close>
     using * by (simp add: p p' off off' shiftl_eq_push_bit push_bit_of_nat push_bit_take_bit word_of_nat_inj flip: of_nat_add)
   then have \<open>int (push_bit n' q + take_bit n' (push_bit n m))
     = int (push_bit n' q' + take_bit n' (push_bit n m'))\<close>
     by simp
   then have \<open>concat_bit n' (int (push_bit n m)) (int q)
     = concat_bit n' (int (push_bit n m')) (int q')\<close>
     by (simp add: of_nat_push_bit of_nat_take_bit bin_cat_eq_push_bit_add_take_bit)
   then show ?thesis
     by (simp add: bin_cat_inj p p' off off' take_bit_of_nat take_bit_push_bit word_of_nat_eq_iff)
       (simp add: push_bit_eq_mult)
 qed
 
 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 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 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) AND NOT(mask n) = (x AND NOT(mask n)) + y * m\<close>
   if \<open>m AND (2 ^ n - 1) = 0\<close>
   for x y m :: \<open>'a::len word\<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: of_nat_diff 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 AND mask n = 0 \<Longrightarrow> x + y AND NOT(mask n) = (x AND NOT(mask n)) + y"
   for x y :: \<open>'a::len word\<close>
   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 AND mask n = 0; y AND 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_iff_dvd_nat)
   done
 
 lemma sub_right_shift:
   "\<lbrakk> x AND mask n = 0; y AND 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 AND mask n = mask n \<Longrightarrow> (x AND y) AND mask n = x AND mask n"
   by (simp add: ac_simps)
 
 lemma and_and_mask_simple_not:
   "y AND mask n = 0 \<Longrightarrow> (x AND y) AND mask n = 0"
   by (simp add: ac_simps)
 
 lemma word_and_le':
   "b \<le> c \<Longrightarrow> (a :: 'a :: len word) AND b \<le> c"
   by (metis word_and_le1 order_trans)
 
 lemma word_and_less':
   "b < c \<Longrightarrow> (a :: 'a :: len word) AND b < c"
   by transfer simp
 
 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 unsigned_uminus1 [simp]:
   \<open>(unsigned (-1::'b::len word)::'c::len word) = mask LENGTH('b)\<close>
   by (rule bit_word_eqI) (auto simp add: bit_simps)
 
 lemma ucast_ucast_mask_eq:
   "\<lbrakk> UCAST('a::len \<rightarrow> 'b::len) x = y; x AND mask LENGTH('b) = x \<rbrakk> \<Longrightarrow> x = ucast y"
   by (drule sym) (simp flip: take_bit_eq_mask add: unsigned_ucast_eq)
 
 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 AND mask n = 0; m \<le> n \<rbrakk> \<Longrightarrow> x AND mask m = 0"
   for x :: \<open>'a::len word\<close>
   by (metis mask_twice2 word_and_notzeroD)
 
 lemma mask_len_id [simp]:
   "(x :: 'a :: len word) AND 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) AND 1 = x \<rbrakk> \<Longrightarrow> x = 0 \<or> x = 1"
   by (metis word_and_1)
 
 lemma shiftr_and_eq_shiftl:
   "(w >> n) AND x = y \<Longrightarrow> w AND (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 add_mask_lower_bits':
   "\<lbrakk> len = LENGTH('a); is_aligned (x :: 'a :: len word) n;
      \<forall>n' \<ge> n. n' < len \<longrightarrow> \<not> bit p n' \<rbrakk>
    \<Longrightarrow> x + p AND NOT(mask n) = x"
   using add_mask_lower_bits by auto
 
 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 AND NOT(mask sz)) + 2 ^ sz - 1"
   for x :: \<open>'a::len word\<close>
   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) AND (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) AND mask m) = unat (x AND mask m)"
   by (metis ucast_and_mask unat_ucast_up_simp)
 
 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"
   apply transfer
   apply (simp add: take_bit_drop_bit)
   apply (simp add: drop_bit_take_bit)
   apply (rule order_trans)
    defer
    apply assumption
   apply (simp add: nat_le_iff of_nat_diff)
   done
 
 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 AND msk = mask n \<rbrakk>
    \<Longrightarrow> (x mod m) AND msk = x mod m"
   for x :: \<open>'a::len word\<close>
   by (simp add: word_mod_2p_is_mask word_bw_assocs)
 
 lemma mask_eq_ucast_eq:
   "\<lbrakk> x AND 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 AND NOT(mask n :: 'a::len word)"
   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 AND NOT(mask sz')) - (ptr AND NOT(mask sz)) \<le> 2 ^ sz - 2 ^ sz'"
   (is "_ \<Longrightarrow> ?lhs \<le> ?rhs")
   for ptr :: \<open>'a::len word\<close>
 proof -
   assume lt: "sz' \<le> sz"
   hence "?lhs = ptr AND (mask sz AND NOT(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_out_eq_0:
   "\<lbrakk> idx < 2 ^ sz; sz < LENGTH('a) \<rbrakk> \<Longrightarrow> (of_nat idx :: 'a :: len word) AND NOT(mask sz) = 0"
   by (simp add: of_nat_power less_mask_eq mask_eq_0_eq_x)
 
 lemma is_aligned_neg_mask_eq':
   "is_aligned ptr sz = (ptr AND NOT(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) AND NOT(mask sz)) + unat (ptr AND 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) 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 AND mask n) = unat d \<and> unat (p + d AND NOT(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) AND NOT(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) AND mask high_bits = x >> low_bits"
   for x :: \<open>'a::len word\<close>
   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 AND mask low_bits = 0) = (x = 0)"
   for x :: \<open>'a::len word\<close>
   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) AND mask n = q AND 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 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) AND mask sz) + unat z < 2 ^ sz; sz < LENGTH('a) \<rbrakk>
    \<Longrightarrow> x \<le> x + z"
   apply (subgoal_tac "(x AND NOT(mask sz)) + (x AND mask sz) \<le> (x AND NOT(mask sz)) + ((x AND 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 of_nat_power is_aligned_no_wrap' by force
 
 lemma mul_not_mask_eq_neg_shiftl:
   "NOT(mask n :: 'a::len word) = -1 << n"
   by (simp add: NOT_mask shiftl_t2n)
 
 lemma shiftr_mul_not_mask_eq_and_not_mask:
   "(x >> n) * NOT(mask n) = - (x AND NOT(mask n))"
   for x :: \<open>'a::len word\<close>
   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) AND NOT(mask n) = p + (x AND NOT(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) AND NOT(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) AND mask (m::nat) = (mask (min m n) :: 'a::len word)"
   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 AND mask m = (if n < m then 2 ^ n else (0 :: 'a::len word))"
   by (rule word_eqI) (auto simp add: bit_simps)
 
 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 (- 1 :: '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 AND mask a >> b) :: 'a :: len word) = p AND 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 AND mask a >> b) :: 'a :: len word) = unat (p AND mask a >> b)"
   by (metis linear ucast_ucast_mask_shift unat_ucast_up_simp)
 
 lemma mask_overlap_zero:
   "a \<le> b \<Longrightarrow> (p AND mask a) AND NOT(mask b) = 0"
   for p :: \<open>'a::len word\<close>
   by (metis NOT_mask_AND_mask mask_lower_twice2 max_def)
 
 lemma mask_shifl_overlap_zero:
   "a + c \<le> b \<Longrightarrow> (p AND mask a << c) AND NOT(mask b) = 0"
   for p :: \<open>'a::len word\<close>
   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 AND NOT(mask a)) AND mask b = 0"
   for p :: \<open>'a::len word\<close>
   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 AND NOT(mask a)) + ((p AND mask a) AND NOT(mask b)) + (p AND mask b) = p"
   for p :: \<open>'a::len word\<close>
   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 AND mask a >> b << b) = (p AND mask a) AND NOT(mask b)"
   for p :: \<open>'a::len word\<close>
   by (simp add: and_not_mask)
 
 lemma mask_shift_sum:
   "\<lbrakk> a \<ge> b; unat n = unat (p AND mask b) \<rbrakk>
    \<Longrightarrow> (p AND NOT(mask a)) + (p AND 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 transfer simp
 
 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 AND 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_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 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 AND mask (size w - n)"
   for w :: \<open>'a::len word\<close>
   by (cases "n \<le> size w"; clarsimp simp: word_and_le2 and_mask shiftl_zero_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 AND mask LENGTH('b) = y AND mask LENGTH('b))"
   by transfer (simp flip: take_bit_eq_mask add: ac_simps)
 
 context
   fixes w :: "'a::len word"
 begin
 
 private lemma sbintrunc_uint_ucast:
   assumes "Suc n = LENGTH('b::len)"
   shows "signed_take_bit n (uint (ucast w :: 'b word)) = signed_take_bit n (uint w)"
   by (rule bit_eqI) (use assms in \<open>simp add: bit_simps\<close>)
 
 private lemma test_bit_sbintrunc:
   assumes "i < LENGTH('a)"
   shows "bit (word_of_int (signed_take_bit n (uint w)) :: 'a word) i
            = (if n < i then bit w n else bit w i)"
   using assms by (simp add: bit_simps)
 
 private lemma test_bit_sbintrunc_ucast:
   assumes len_a: "i < LENGTH('a)"
   shows "bit (word_of_int (signed_take_bit (LENGTH('b) - 1) (uint (ucast w :: 'b word))) :: 'a word) i
           = (if LENGTH('b::len) \<le> i then bit w (LENGTH('b) - 1) else bit w i)"
   using len_a by (auto simp add: sbintrunc_uint_ucast bit_simps)
 
 lemma scast_ucast_high_bits:
   \<open>scast (ucast w :: 'b::len word) = w
      \<longleftrightarrow> (\<forall> i \<in> {LENGTH('b) ..< size w}. bit w i = bit 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> NOT(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 AND mask LENGTH('b))"
   apply (simp flip: take_bit_eq_mask)
   apply transfer
   apply simp
   done
 
 lemma ucast_NOT:
   "ucast (NOT x) = NOT(ucast x) AND 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) (NOT x) = NOT(UCAST('a \<rightarrow> 'b) x)"
   by word_eqI
 
 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 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 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_exp_eq 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_wi scast_down_wi
   ucast_of_nat scast_of_nat
   uint_up_ucast sint_up_scast
   up_scast_surj up_ucast_surj
 
 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: signed_divide_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]
 
 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)+
 
 end