diff --git a/src/HOL/Word/Bits_Int.thy b/src/HOL/Word/Bits_Int.thy --- a/src/HOL/Word/Bits_Int.thy +++ b/src/HOL/Word/Bits_Int.thy @@ -1,2678 +1,2685 @@ (* Title: HOL/Word/Bits_Int.thy Author: Jeremy Dawson and Gerwin Klein, NICTA Definitions and basic theorems for bit-wise logical operations for integers expressed using Pls, Min, BIT, and converting them to and from lists of bools. *) section \Bitwise Operations on integers\ theory Bits_Int imports Bits Misc_Auxiliary begin subsection \Implicit bit representation of \<^typ>\int\\ definition Bit :: "int \ bool \ int" (infixl "BIT" 90) where "k BIT b = (if b then 1 else 0) + k + k" lemma Bit_B0: "k BIT False = k + k" by (simp add: Bit_def) lemma Bit_B1: "k BIT True = k + k + 1" by (simp add: Bit_def) lemma Bit_B0_2t: "k BIT False = 2 * k" by (rule trans, rule Bit_B0) simp lemma Bit_B1_2t: "k BIT True = 2 * k + 1" by (rule trans, rule Bit_B1) simp lemma uminus_Bit_eq: "- k BIT b = (- k - of_bool b) BIT b" by (cases b) (simp_all add: Bit_def) lemma power_BIT: "2 ^ Suc n - 1 = (2 ^ n - 1) BIT True" by (simp add: Bit_B1) abbreviation (input) bin_last :: "int \ bool" where "bin_last \ odd" lemma bin_last_def: "bin_last w \ w mod 2 = 1" by (fact odd_iff_mod_2_eq_one) abbreviation (input) bin_rest :: "int \ int" where "bin_rest w \ w div 2" lemma bin_rl_simp [simp]: "bin_rest w BIT bin_last w = w" by (simp add: Bit_def) lemma bin_rest_BIT [simp]: "bin_rest (x BIT b) = x" by (simp add: Bit_def) lemma even_BIT [simp]: "even (x BIT b) \ \ b" by (simp add: Bit_def) lemma bin_last_BIT [simp]: "bin_last (x BIT b) = b" by simp lemma BIT_eq_iff [iff]: "u BIT b = v BIT c \ u = v \ b = c" by (auto simp: Bit_def) arith+ lemma BIT_bin_simps [simp]: "numeral k BIT False = numeral (Num.Bit0 k)" "numeral k BIT True = numeral (Num.Bit1 k)" "(- numeral k) BIT False = - numeral (Num.Bit0 k)" "(- numeral k) BIT True = - numeral (Num.BitM k)" by (simp_all only: Bit_B0 Bit_B1 numeral.simps numeral_BitM) lemma BIT_special_simps [simp]: shows "0 BIT False = 0" and "0 BIT True = 1" and "1 BIT False = 2" and "1 BIT True = 3" and "(- 1) BIT False = - 2" and "(- 1) BIT True = - 1" by (simp_all add: Bit_def) lemma Bit_eq_0_iff: "w BIT b = 0 \ w = 0 \ \ b" by (auto simp: Bit_def) arith lemma Bit_eq_m1_iff: "w BIT b = -1 \ w = -1 \ b" by (auto simp: Bit_def) arith lemma BitM_inc: "Num.BitM (Num.inc w) = Num.Bit1 w" by (induct w) simp_all lemma expand_BIT: "numeral (Num.Bit0 w) = numeral w BIT False" "numeral (Num.Bit1 w) = numeral w BIT True" "- numeral (Num.Bit0 w) = (- numeral w) BIT False" "- numeral (Num.Bit1 w) = (- numeral (w + Num.One)) BIT True" by (simp_all add: add_One BitM_inc) lemma bin_last_numeral_simps [simp]: "\ bin_last 0" "bin_last 1" "bin_last (- 1)" "bin_last Numeral1" "\ bin_last (numeral (Num.Bit0 w))" "bin_last (numeral (Num.Bit1 w))" "\ bin_last (- numeral (Num.Bit0 w))" "bin_last (- numeral (Num.Bit1 w))" by simp_all lemma bin_rest_numeral_simps [simp]: "bin_rest 0 = 0" "bin_rest 1 = 0" "bin_rest (- 1) = - 1" "bin_rest Numeral1 = 0" "bin_rest (numeral (Num.Bit0 w)) = numeral w" "bin_rest (numeral (Num.Bit1 w)) = numeral w" "bin_rest (- numeral (Num.Bit0 w)) = - numeral w" "bin_rest (- numeral (Num.Bit1 w)) = - numeral (w + Num.One)" by simp_all lemma less_Bits: "v BIT b < w BIT c \ v < w \ v \ w \ \ b \ c" by (auto simp: Bit_def) lemma le_Bits: "v BIT b \ w BIT c \ v < w \ v \ w \ (\ b \ c)" by (auto simp: Bit_def) lemma pred_BIT_simps [simp]: "x BIT False - 1 = (x - 1) BIT True" "x BIT True - 1 = x BIT False" by (simp_all add: Bit_B0_2t Bit_B1_2t) lemma succ_BIT_simps [simp]: "x BIT False + 1 = x BIT True" "x BIT True + 1 = (x + 1) BIT False" by (simp_all add: Bit_B0_2t Bit_B1_2t) lemma add_BIT_simps [simp]: "x BIT False + y BIT False = (x + y) BIT False" "x BIT False + y BIT True = (x + y) BIT True" "x BIT True + y BIT False = (x + y) BIT True" "x BIT True + y BIT True = (x + y + 1) BIT False" by (simp_all add: Bit_B0_2t Bit_B1_2t) lemma mult_BIT_simps [simp]: "x BIT False * y = (x * y) BIT False" "x * y BIT False = (x * y) BIT False" "x BIT True * y = (x * y) BIT False + y" by (simp_all add: Bit_B0_2t Bit_B1_2t algebra_simps) lemma B_mod_2': "X = 2 \ (w BIT True) mod X = 1 \ (w BIT False) mod X = 0" by (simp add: Bit_B0 Bit_B1) lemma bin_ex_rl: "\w b. w BIT b = bin" by (metis bin_rl_simp) lemma bin_exhaust: "(\x b. bin = x BIT b \ Q) \ Q" by (metis bin_ex_rl) lemma bin_abs_lem: "bin = (w BIT b) \ bin \ -1 \ bin \ 0 \ nat \w\ < nat \bin\" apply clarsimp apply (unfold Bit_def) apply (cases b) apply (clarsimp, arith) apply (clarsimp, arith) done lemma bin_induct: assumes PPls: "P 0" and PMin: "P (- 1)" and PBit: "\bin bit. P bin \ P (bin BIT bit)" shows "P bin" apply (rule_tac P=P and a=bin and f1="nat \ abs" in wf_measure [THEN wf_induct]) apply (simp add: measure_def inv_image_def) apply (case_tac x rule: bin_exhaust) apply (frule bin_abs_lem) apply (auto simp add : PPls PMin PBit) done lemma Bit_div2: "(w BIT b) div 2 = w" by (fact bin_rest_BIT) lemma bin_rl_eqI: "\bin_rest x = bin_rest y; bin_last x = bin_last y\ \ x = y" by (metis (mono_tags) BIT_eq_iff bin_ex_rl bin_last_BIT bin_rest_BIT) lemma twice_conv_BIT: "2 * x = x BIT False" by (simp add: Bit_def) lemma BIT_lt0 [simp]: "x BIT b < 0 \ x < 0" by(cases b)(auto simp add: Bit_def) lemma BIT_ge0 [simp]: "x BIT b \ 0 \ x \ 0" by(cases b)(auto simp add: Bit_def) lemma [simp]: shows bin_rest_lt0: "bin_rest i < 0 \ i < 0" and bin_rest_ge_0: "bin_rest i \ 0 \ i \ 0" by auto lemma bin_rest_gt_0 [simp]: "bin_rest x > 0 \ x > 1" by auto subsection \Explicit bit representation of \<^typ>\int\\ primrec bl_to_bin_aux :: "bool list \ int \ int" where Nil: "bl_to_bin_aux [] w = w" | Cons: "bl_to_bin_aux (b # bs) w = bl_to_bin_aux bs (w BIT b)" definition bl_to_bin :: "bool list \ int" where "bl_to_bin bs = bl_to_bin_aux bs 0" primrec bin_to_bl_aux :: "nat \ int \ bool list \ 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 (bin_rest w) ((bin_last w) # bl)" definition bin_to_bl :: "nat \ int \ 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 \ 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 \ 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 \ 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_Bit_minus_simp [simp]: "0 < n \ bin_to_bl_aux n (w BIT b) bl = bin_to_bl_aux (n - 1) w (b # bl)" by (cases n) auto lemma bin_to_bl_aux_Bit0_minus_simp [simp]: "0 < n \ 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 \ 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 \ length bs = length cs \ 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) lemma bl_to_bin_BIT: "bl_to_bin bs BIT b = bl_to_bin (bs @ [b])" by (simp add: bl_to_bin_append) subsection \Bit projection\ abbreviation (input) bin_nth :: \int \ nat \ bool\ where \bin_nth \ bit\ lemma bin_nth_eq_iff: "bin_nth x = bin_nth y \ x = y" by (simp add: bit_eq_iff fun_eq_iff) lemma bin_eqI: "x = y" if "\n. bin_nth x n \ bin_nth y n" using that bin_nth_eq_iff [of x y] by (simp add: fun_eq_iff) lemma bin_eq_iff: "x = y \ (\n. bin_nth x n = bin_nth y n)" by (fact bit_eq_iff) lemma bin_nth_zero [simp]: "\ bin_nth 0 n" by simp lemma bin_nth_1 [simp]: "bin_nth 1 n \ n = 0" by (cases n) (simp_all add: bit_Suc) lemma bin_nth_minus1 [simp]: "bin_nth (- 1) n" by (induction n) (simp_all add: bit_Suc) lemma bin_nth_0_BIT: "bin_nth (w BIT b) 0 \ b" by simp lemma bin_nth_Suc_BIT: "bin_nth (w BIT b) (Suc n) = bin_nth w n" by (simp add: bit_Suc) lemma bin_nth_minus [simp]: "0 < n \ bin_nth (w BIT b) n = bin_nth w (n - 1)" by (cases n) (simp_all add: bit_Suc) lemma bin_nth_numeral: "bin_rest x = y \ bin_nth x (numeral n) = bin_nth 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(2)] bin_nth_numeral [OF bin_rest_numeral_simps(5)] bin_nth_numeral [OF bin_rest_numeral_simps(6)] bin_nth_numeral [OF bin_rest_numeral_simps(7)] 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: "bin_nth (2 ^ n) m = (m = n)" \ \for use when simplifying with \bin_nth_Bit\\ by (auto simp add: bit_exp_iff) lemma nth_rest_power_bin: "bin_nth ((bin_rest ^^ k) w) n = bin_nth 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: "bin_nth (numeral (num.Bit0 x)) n \ n > 0 \ bin_nth (numeral x) (n - 1)" "bin_nth (numeral (num.Bit1 x)) n \ (n > 0 \ bin_nth (numeral x) (n - 1))" by (cases n; simp)+ subsection \Truncating\ definition bin_sign :: "int \ int" where "bin_sign k = (if k \ 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" "bin_sign (w BIT b) = bin_sign w" by (simp_all add: bin_sign_def Bit_def) lemma bin_sign_rest [simp]: "bin_sign (bin_rest w) = bin_sign w" by (cases w rule: bin_exhaust) auto abbreviation (input) bintrunc :: "nat \ int \ int" where \bintrunc \ take_bit\ primrec sbintrunc :: "nat \ int \ int" where Z : "sbintrunc 0 bin = (if bin_last bin then -1 else 0)" | Suc : "sbintrunc (Suc n) bin = sbintrunc n (bin_rest bin) BIT (bin_last bin)" lemma bintrunc_mod2p: "bintrunc n w = w mod 2 ^ n" by (fact take_bit_eq_mod) lemma sbintrunc_mod2p: "sbintrunc n w = (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n" proof (induction n arbitrary: w) case 0 then show ?case by (auto simp add: odd_iff_mod_2_eq_one) next case (Suc n) moreover have "((bin_rest w + 2 ^ n) mod (2 * 2 ^ n) - 2 ^ n) BIT bin_last w = (w + 2 * 2 ^ n) mod (4 * 2 ^ n) - 2 * 2 ^ n" proof (cases w rule: parity_cases) case even then show ?thesis by (simp add: Bit_B0_2t mult_mod_right) next case odd then have "2 * (w div 2) = w - 1" using minus_mod_eq_mult_div [of w 2] by simp moreover have "(2 * 2 ^ n + w - 1) mod (2 * 2 * 2 ^ n) + 1 = (2 * 2 ^ n + w) mod (2 * 2 * 2 ^ n)" using odd emep1 [of "2 * 2 ^ n + w - 1" "2 * 2 * 2 ^ n"] by simp ultimately show ?thesis using odd by (simp add: Bit_B1_2t mult_mod_right) (simp add: algebra_simps) qed ultimately show ?case by simp qed lemma sign_bintr: "bin_sign (bintrunc n w) = 0" by (simp add: bintrunc_mod2p bin_sign_def) lemma bintrunc_n_0 [simp]: "bintrunc n 0 = 0" by (simp add: bintrunc_mod2p) lemma sbintrunc_n_0 [simp]: "sbintrunc n 0 = 0" by (simp add: sbintrunc_mod2p) lemma sbintrunc_n_minus1 [simp]: "sbintrunc n (- 1) = -1" by (induct n) auto lemma bintrunc_Suc_numeral: "bintrunc (Suc n) 1 = 1" "bintrunc (Suc n) (- 1) = bintrunc n (- 1) BIT True" "bintrunc (Suc n) (numeral (Num.Bit0 w)) = bintrunc n (numeral w) BIT False" "bintrunc (Suc n) (numeral (Num.Bit1 w)) = bintrunc n (numeral w) BIT True" "bintrunc (Suc n) (- numeral (Num.Bit0 w)) = bintrunc n (- numeral w) BIT False" "bintrunc (Suc n) (- numeral (Num.Bit1 w)) = bintrunc n (- numeral (w + Num.One)) BIT True" by (simp_all add: take_bit_Suc Bit_def) lemma sbintrunc_0_numeral [simp]: "sbintrunc 0 1 = -1" "sbintrunc 0 (numeral (Num.Bit0 w)) = 0" "sbintrunc 0 (numeral (Num.Bit1 w)) = -1" "sbintrunc 0 (- numeral (Num.Bit0 w)) = 0" "sbintrunc 0 (- numeral (Num.Bit1 w)) = -1" by simp_all lemma sbintrunc_Suc_numeral: "sbintrunc (Suc n) 1 = 1" "sbintrunc (Suc n) (numeral (Num.Bit0 w)) = sbintrunc n (numeral w) BIT False" "sbintrunc (Suc n) (numeral (Num.Bit1 w)) = sbintrunc n (numeral w) BIT True" "sbintrunc (Suc n) (- numeral (Num.Bit0 w)) = sbintrunc n (- numeral w) BIT False" "sbintrunc (Suc n) (- numeral (Num.Bit1 w)) = sbintrunc n (- numeral (w + Num.One)) BIT True" by simp_all lemma bin_sign_lem: "(bin_sign (sbintrunc n bin) = -1) = bin_nth bin n" by (induct n arbitrary: bin) (simp_all add: bit_Suc) lemma nth_bintr: "bin_nth (bintrunc m w) n \ n < m \ bin_nth w n" by (fact bit_take_bit_iff) lemma nth_sbintr: "bin_nth (sbintrunc m w) n = (if n < m then bin_nth w n else bin_nth w m)" apply (induct n arbitrary: w m) apply (case_tac m) apply simp_all apply (case_tac m) apply (simp_all add: bit_Suc) done lemma bin_nth_Bit: "bin_nth (w BIT b) n \ n = 0 \ b \ (\m. n = Suc m \ bin_nth w m)" by (cases n) auto lemma bin_nth_Bit0: "bin_nth (numeral (Num.Bit0 w)) n \ (\m. n = Suc m \ bin_nth (numeral w) m)" using bin_nth_Bit [where w="numeral w" and b="False"] by simp lemma bin_nth_Bit1: "bin_nth (numeral (Num.Bit1 w)) n \ n = 0 \ (\m. n = Suc m \ bin_nth (numeral w) m)" using bin_nth_Bit [where w="numeral w" and b="True"] by simp lemma bintrunc_bintrunc_l: "n \ m \ bintrunc m (bintrunc n w) = bintrunc n w" by (simp add: min.absorb2) lemma sbintrunc_sbintrunc_l: "n \ m \ sbintrunc m (sbintrunc n w) = sbintrunc n w" by (rule bin_eqI) (auto simp: nth_sbintr) lemma bintrunc_bintrunc_ge: "n \ m \ bintrunc n (bintrunc m w) = bintrunc n w" by (rule bin_eqI) (auto simp: nth_bintr) lemma bintrunc_bintrunc_min [simp]: "bintrunc m (bintrunc n w) = bintrunc (min m n) w" by (rule bin_eqI) (auto simp: nth_bintr) lemma sbintrunc_sbintrunc_min [simp]: "sbintrunc m (sbintrunc n w) = sbintrunc (min m n) w" by (rule bin_eqI) (auto simp: nth_sbintr min.absorb1 min.absorb2) lemmas sbintrunc_Suc_Pls = sbintrunc.Suc [where bin="0", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Suc_Min = sbintrunc.Suc [where bin="-1", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Suc_BIT [simp] = sbintrunc.Suc [where bin="w BIT b", simplified bin_last_BIT bin_rest_BIT] for w b lemmas sbintrunc_Sucs = sbintrunc_Suc_Pls sbintrunc_Suc_Min sbintrunc_Suc_BIT sbintrunc_Suc_numeral lemmas sbintrunc_Pls = sbintrunc.Z [where bin="0", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Min = sbintrunc.Z [where bin="-1", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_0_BIT_B0 [simp] = sbintrunc.Z [where bin="w BIT False", simplified bin_last_numeral_simps bin_rest_numeral_simps] for w lemmas sbintrunc_0_BIT_B1 [simp] = sbintrunc.Z [where bin="w BIT True", simplified bin_last_BIT bin_rest_numeral_simps] for w lemmas sbintrunc_0_simps = sbintrunc_Pls sbintrunc_Min sbintrunc_0_BIT_B0 sbintrunc_0_BIT_B1 lemmas sbintrunc_simps = sbintrunc_0_simps sbintrunc_Sucs lemma bintrunc_minus: "0 < n \ bintrunc (Suc (n - 1)) w = bintrunc n w" by auto lemma sbintrunc_minus: "0 < n \ sbintrunc (Suc (n - 1)) w = sbintrunc n w" by auto lemmas sbintrunc_minus_simps = sbintrunc_Sucs [THEN [2] sbintrunc_minus [symmetric, THEN trans]] -lemmas thobini1 = arg_cong [where f = "\w. w BIT b"] for b - -lemmas sbintrunc_BIT_I = trans [OF sbintrunc_Suc_BIT thobini1] - -lemmas sbintrunc_Suc_Is = - sbintrunc_Sucs(1-3) [THEN thobini1 [THEN [2] trans]] - -lemmas sbintrunc_Suc_minus_Is = - sbintrunc_minus_simps(1-3) [THEN thobini1 [THEN [2] trans]] +lemma sbintrunc_BIT_I: + \0 < n \ + sbintrunc (n - 1) 0 = y \ + sbintrunc n 0 = 2 * y\ + by simp + +lemma sbintrunc_Suc_Is: + \sbintrunc n (- 1) = y \ + sbintrunc (Suc n) (- 1) = 1 + 2 * y\ + by (auto simp add: Bit_def) + +lemma sbintrunc_Suc_minus_Is: + \0 < n \ + sbintrunc (n - 1) w = y \ + sbintrunc n (w BIT b) = y BIT b\ + by (cases n) simp_all lemma sbintrunc_Suc_lem: "sbintrunc (Suc n) x = y \ m = Suc n \ sbintrunc m x = y" by auto lemmas sbintrunc_Suc_Ialts = sbintrunc_Suc_Is [THEN sbintrunc_Suc_lem] lemma sbintrunc_bintrunc_lt: "m > n \ sbintrunc n (bintrunc m w) = sbintrunc n w" by (rule bin_eqI) (auto simp: nth_sbintr nth_bintr) lemma bintrunc_sbintrunc_le: "m \ Suc n \ bintrunc m (sbintrunc n w) = bintrunc m w" apply (rule bin_eqI) using le_Suc_eq less_Suc_eq_le apply (auto simp: nth_sbintr nth_bintr) done 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 \ bintrunc n (sbintrunc (n - 1) w) = bintrunc n w" by (cases n) simp_all lemma sbintrunc_bintrunc' [simp]: "0 < n \ sbintrunc (n - 1) (bintrunc n w) = sbintrunc (n - 1) w" by (cases n) simp_all lemma bin_sbin_eq_iff: "bintrunc (Suc n) x = bintrunc (Suc n) y \ sbintrunc n x = sbintrunc 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 \ bintrunc n x = bintrunc n y \ sbintrunc (n - 1) x = sbintrunc (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: "bintrunc (numeral k) x = bintrunc (pred_numeral k) (bin_rest x) BIT bin_last x" by (simp add: numeral_eq_Suc take_bit_Suc Bit_def mod_2_eq_odd) lemma sbintrunc_numeral: "sbintrunc (numeral k) x = sbintrunc (pred_numeral k) (bin_rest x) BIT bin_last x" by (simp add: numeral_eq_Suc) lemma bintrunc_numeral_simps [simp]: "bintrunc (numeral k) (numeral (Num.Bit0 w)) = bintrunc (pred_numeral k) (numeral w) BIT False" "bintrunc (numeral k) (numeral (Num.Bit1 w)) = bintrunc (pred_numeral k) (numeral w) BIT True" "bintrunc (numeral k) (- numeral (Num.Bit0 w)) = bintrunc (pred_numeral k) (- numeral w) BIT False" "bintrunc (numeral k) (- numeral (Num.Bit1 w)) = bintrunc (pred_numeral k) (- numeral (w + Num.One)) BIT True" "bintrunc (numeral k) 1 = 1" by (simp_all add: bintrunc_numeral) lemma sbintrunc_numeral_simps [simp]: "sbintrunc (numeral k) (numeral (Num.Bit0 w)) = sbintrunc (pred_numeral k) (numeral w) BIT False" "sbintrunc (numeral k) (numeral (Num.Bit1 w)) = sbintrunc (pred_numeral k) (numeral w) BIT True" "sbintrunc (numeral k) (- numeral (Num.Bit0 w)) = sbintrunc (pred_numeral k) (- numeral w) BIT False" "sbintrunc (numeral k) (- numeral (Num.Bit1 w)) = sbintrunc (pred_numeral k) (- numeral (w + Num.One)) BIT True" "sbintrunc (numeral k) 1 = 1" by (simp_all add: sbintrunc_numeral) lemma no_bintr_alt1: "bintrunc n = (\w. w mod 2 ^ n :: int)" by (rule ext) (rule bintrunc_mod2p) lemma range_bintrunc: "range (bintrunc n) = {i. 0 \ i \ i < 2 ^ n}" apply (unfold no_bintr_alt1) apply (auto simp add: image_iff) apply (rule exI) apply (rule sym) using int_mod_lem [symmetric, of "2 ^ n"] apply auto done lemma no_sbintr_alt2: "sbintrunc n = (\w. (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n :: int)" by (rule ext) (simp add : sbintrunc_mod2p) lemma range_sbintrunc: "range (sbintrunc n) = {i. - (2 ^ n) \ i \ i < 2 ^ n}" apply (unfold no_sbintr_alt2) apply (auto simp add: image_iff eq_diff_eq) apply (rule exI) apply (auto intro: int_mod_lem [THEN iffD1, symmetric]) done lemma sb_inc_lem: "a + 2^k < 0 \ a + 2^k + 2^(Suc k) \ (a + 2^k) mod 2^(Suc k)" for a :: int using int_mod_ge' [where n = "2 ^ (Suc k)" and b = "a + 2 ^ k"] by simp lemma sb_inc_lem': "a < - (2^k) \ a + 2^k + 2^(Suc k) \ (a + 2^k) mod 2^(Suc k)" for a :: int by (rule sb_inc_lem) simp lemma sbintrunc_inc: "x < - (2^n) \ x + 2^(Suc n) \ sbintrunc n x" unfolding no_sbintr_alt2 by (drule sb_inc_lem') simp lemma sb_dec_lem: "0 \ - (2 ^ k) + a \ (a + 2 ^ k) mod (2 * 2 ^ k) \ - (2 ^ k) + a" for a :: int using int_mod_le'[where n = "2 ^ (Suc k)" and b = "a + 2 ^ k"] by simp lemma sb_dec_lem': "2 ^ k \ a \ (a + 2 ^ k) mod (2 * 2 ^ k) \ - (2 ^ k) + a" for a :: int by (rule sb_dec_lem) simp lemma sbintrunc_dec: "x \ (2 ^ n) \ x - 2 ^ (Suc n) >= sbintrunc n x" unfolding no_sbintr_alt2 by (drule sb_dec_lem') simp lemma bintr_ge0: "0 \ bintrunc n w" by (simp add: bintrunc_mod2p) lemma bintr_lt2p: "bintrunc n w < 2 ^ n" by (simp add: bintrunc_mod2p) lemma bintr_Min: "bintrunc n (- 1) = 2 ^ n - 1" by (simp add: bintrunc_mod2p m1mod2k) lemma sbintr_ge: "- (2 ^ n) \ sbintrunc n w" by (simp add: sbintrunc_mod2p) lemma sbintr_lt: "sbintrunc n w < 2 ^ n" by (simp add: sbintrunc_mod2p) lemma sign_Pls_ge_0: "bin_sign bin = 0 \ bin \ 0" for bin :: int by (simp add: bin_sign_def) lemma sign_Min_lt_0: "bin_sign bin = -1 \ bin < 0" for bin :: int by (simp add: bin_sign_def) lemma bin_rest_trunc: "bin_rest (bintrunc n bin) = bintrunc (n - 1) (bin_rest bin)" by (simp add: take_bit_rec [of n bin]) lemma bin_rest_power_trunc: "(bin_rest ^^ k) (bintrunc n bin) = bintrunc (n - k) ((bin_rest ^^ k) bin)" by (induct k) (auto simp: bin_rest_trunc) lemma bin_rest_trunc_i: "bintrunc n (bin_rest bin) = bin_rest (bintrunc (Suc n) bin)" by (auto simp add: take_bit_Suc) lemma bin_rest_strunc: "bin_rest (sbintrunc (Suc n) bin) = sbintrunc n (bin_rest bin)" by (induct n arbitrary: bin) auto lemma bintrunc_rest [simp]: "bintrunc n (bin_rest (bintrunc n bin)) = bin_rest (bintrunc n bin)" by (induct n arbitrary: bin) (simp_all add: take_bit_Suc) lemma sbintrunc_rest [simp]: "sbintrunc n (bin_rest (sbintrunc n bin)) = bin_rest (sbintrunc n bin)" apply (induct n arbitrary: bin) apply simp apply (case_tac bin rule: bin_exhaust) apply (auto simp: bintrunc_bintrunc_l split: bool.splits) done lemma bintrunc_rest': "bintrunc n \ bin_rest \ bintrunc n = bin_rest \ bintrunc n" by (rule ext) auto lemma sbintrunc_rest': "sbintrunc n \ bin_rest \ sbintrunc n = bin_rest \ sbintrunc n" by (rule ext) auto lemma rco_lem: "f \ g \ f = g \ f \ f \ (g \ f) ^^ n = g ^^ n \ 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 \Splitting and concatenation\ definition bin_split :: \nat \ int \ int \ int\ where [simp]: \bin_split n k = (drop_bit n k, take_bit n k)\ lemma [code]: "bin_split (Suc n) w = (let (w1, w2) = bin_split n (bin_rest w) in (w1, w2 BIT bin_last w))" "bin_split 0 w = (w, 0)" by (simp_all add: Bit_def drop_bit_Suc take_bit_Suc mod_2_eq_odd) primrec bin_cat :: "int \ nat \ int \ int" where Z: "bin_cat w 0 v = w" | Suc: "bin_cat w (Suc n) v = bin_cat w n (bin_rest v) BIT bin_last v" lemma bin_cat_eq_push_bit_add_take_bit: \bin_cat k n l = push_bit n k + take_bit n l\ by (induction n arbitrary: k l) (simp_all add: Bit_def take_bit_Suc push_bit_double mod_2_eq_odd) lemma bin_sign_cat: "bin_sign (bin_cat x n y) = bin_sign x" by (induct n arbitrary: y) auto lemma bin_cat_Suc_Bit: "bin_cat w (Suc n) (v BIT b) = bin_cat w n v BIT b" by auto lemma bin_cat_assoc: "bin_cat (bin_cat x m y) n z = bin_cat x (m + n) (bin_cat y n z)" by (induct n arbitrary: z) auto lemma bin_cat_assoc_sym: "bin_cat x m (bin_cat y n z) = bin_cat (bin_cat x (m - n) y) (min m n) z" apply (induct n arbitrary: z m) apply clarsimp apply (case_tac m, auto) done definition bin_rcat :: "nat \ int list \ int" where "bin_rcat n = foldl (\u v. bin_cat u n v) 0" fun bin_rsplit_aux :: "nat \ nat \ int \ int list \ int list" where "bin_rsplit_aux n m c bs = (if m = 0 \ 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 \ nat \ int \ int list" where "bin_rsplit n w = bin_rsplit_aux n (fst w) (snd w) []" fun bin_rsplitl_aux :: "nat \ nat \ int \ int list \ int list" where "bin_rsplitl_aux n m c bs = (if m = 0 \ 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 \ nat \ int \ 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: "bin_nth (bin_cat x k y) n = (if n < k then bin_nth y n else bin_nth x (n - k))" apply (induct k arbitrary: n y) apply simp apply (case_tac n) apply (simp_all add: bit_Suc) done lemma bin_nth_drop_bit_iff: \bin_nth (drop_bit n c) k \ bin_nth c (n + k)\ by (simp add: bit_drop_bit_eq) lemma bin_nth_take_bit_iff: \bin_nth (take_bit n c) k \ k < n \ bin_nth c k\ by (fact bit_take_bit_iff) lemma bin_nth_split: "bin_split n c = (a, b) \ (\k. bin_nth a k = bin_nth c (n + k)) \ (\k. bin_nth b k = (k < n \ bin_nth c k))" by (auto simp add: bin_nth_drop_bit_iff bin_nth_take_bit_iff) lemma bin_cat_zero [simp]: "bin_cat 0 n w = bintrunc n w" by (simp add: bin_cat_eq_push_bit_add_take_bit) lemma bintr_cat1: "bintrunc (k + n) (bin_cat a n b) = bin_cat (bintrunc k a) n b" by (metis bin_cat_assoc bin_cat_zero) lemma bintr_cat: "bintrunc m (bin_cat a n b) = bin_cat (bintrunc (m - n) a) n (bintrunc (min m n) b)" by (rule bin_eqI) (auto simp: bin_nth_cat nth_bintr) lemma bintr_cat_same [simp]: "bintrunc n (bin_cat a n b) = bintrunc n b" by (auto simp add : bintr_cat) lemma cat_bintr [simp]: "bin_cat a n (bintrunc n b) = bin_cat a n b" by (simp add: bin_cat_eq_push_bit_add_take_bit) lemma split_bintrunc: "bin_split n c = (a, b) \ b = bintrunc n c" by simp lemma bin_cat_split: "bin_split n w = (u, v) \ w = bin_cat u n v" by (auto simp add: bin_cat_eq_push_bit_add_take_bit bits_ident) lemma drop_bit_bin_cat_eq: \drop_bit n (bin_cat v n w) = v\ by (induct n arbitrary: w) (simp_all add: Bit_def drop_bit_Suc) lemma take_bit_bin_cat_eq: \take_bit n (bin_cat v n w) = take_bit n w\ by (induct n arbitrary: w) (simp_all add: Bit_def take_bit_Suc mod_2_eq_odd) lemma bin_split_cat: "bin_split n (bin_cat v n w) = (v, bintrunc 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, bintrunc n (- 1))" by simp lemma bin_split_trunc: "bin_split (min m n) c = (a, b) \ bin_split n (bintrunc m c) = (bintrunc (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) \ bin_split n (bintrunc m c) = (bintrunc (m - n) a, bintrunc 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 Bit_def mod_2_eq_odd split: prod.split_asm) done lemma bin_cat_num: "bin_cat a n b = a * 2 ^ n + bintrunc 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] \ \these safe to \[simp add]\ as require calculating \m - n\\ 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 \ bin_split (Suc (n - 1)) w = bin_split n w" by auto lemma bin_split_pred_simp [simp]: "(0::nat) < numeral bin \ bin_split (numeral bin) w = (let (w1, w2) = bin_split (numeral bin - 1) (bin_rest w) in (w1, w2 BIT bin_last w))" by (simp add: Bit_def 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 \ 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 \ rev sw = bin_rsplit n (nw, w) \ \v\set sw. bintrunc 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 \ m < n \ \w k nw. rev sw = bin_rsplit n (nw, w) \ k < size sw \ bin_nth (sw ! k) m = bin_nth 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 clarify 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 \ nw \ n \ bin_rsplit n (nw, w) = [bintrunc n w]" by (auto simp: bin_rsplit_def rsplit_aux_simp2ls split: prod.split dest!: split_bintrunc) lemma bin_rsplit_l [rule_format]: "\bin. bin_rsplitl n (m, bin) = bin_rsplit n (m, bintrunc 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 \x < n\) apply (simp_all add: not_less min_def) done lemma bin_rsplit_rcat [rule_format]: "n > 0 \ bin_rsplit n (n * size ws, bin_rcat n ws) = map (bintrunc n) ws" apply (unfold bin_rsplit_def bin_rcat_def) 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] : "\ws m. n \ 0 \ ws = bin_rsplit_aux n nw w bs \ length ws \ m \ nw + length bs * n \ m * n" proof - have *: R if d: "i \ j \ m < j'" and R1: "i * k \ j * k \ R" and R2: "Suc m * k' \ j' * k' \ 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 \ sc - n + (n + lb * n) \ m * n \ sc + lb * n \ m * n" for sc m n lb :: nat apply safe apply arith apply (case_tac "sc \ 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 \ 0 \ ws = bin_rsplit n (nw, w) \ length ws \ m \ nw \ m * n" by (auto simp: bin_rsplit_def bin_rsplit_aux_len_le) lemma bin_rsplit_aux_len: "n \ 0 \ 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 \ n") apply (auto simp add: div_add_self2) done lemma bin_rsplit_len: "n \ 0 \ 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 \ 0 \ length bs = length cs \ 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 \length bs = length cs\ show ?thesis by simp next case False from "1.hyps" [of \bin_split n w\ \drop_bit n w\ \take_bit n w\] \m \ 0\ \n \ 0\ have hyp: "\v bs. length bs = Suc (length cs) \ 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 \length bs = length cs\ \n \ 0\ 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 \ 0 \ 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 \Logical operations\ primrec bin_sc :: "nat \ bool \ int \ int" where Z: "bin_sc 0 b w = bin_rest w BIT b" | Suc: "bin_sc (Suc n) b w = bin_sc n b (bin_rest w) BIT bin_last w" lemma bin_nth_sc [simp]: "bin_nth (bin_sc n b w) n \ b" by (induct n arbitrary: w) auto lemma bin_sc_sc_same [simp]: "bin_sc n c (bin_sc n b w) = bin_sc n c w" by (induct n arbitrary: w) auto lemma bin_sc_sc_diff: "m \ n \ 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: "bin_nth (bin_sc n b w) m = (if m = n then b else bin_nth 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_nth [simp]: "bin_sc n (bin_nth w n) w = w" by (induct n arbitrary: w) (simp_all add: bit_Suc) lemma bin_sign_sc [simp]: "bin_sign (bin_sc n b w) = bin_sign w" by (induct n arbitrary: w) auto lemma bin_sc_bintr [simp]: "bintrunc m (bin_sc n x (bintrunc m (w))) = bintrunc m (bin_sc n x w)" apply (induct n arbitrary: w m) apply (case_tac [!] w rule: bin_exhaust) apply (case_tac [!] m, auto simp add: take_bit_Suc mod_2_eq_odd) done lemma bin_clr_le: "bin_sc n False w \ w" apply (induct n arbitrary: w) apply (case_tac [!] w rule: bin_exhaust) apply (auto simp: le_Bits) done lemma bin_set_ge: "bin_sc n True w \ w" apply (induct n arbitrary: w) apply (case_tac [!] w rule: bin_exhaust) apply (auto simp: le_Bits) done lemma bintr_bin_clr_le: "bintrunc n (bin_sc m False w) \ bintrunc n w" apply (induct n arbitrary: w m) apply simp apply (case_tac w rule: bin_exhaust) apply (case_tac m) apply (auto simp: le_Bits take_bit_Suc mod_2_eq_odd) done lemma bintr_bin_set_ge: "bintrunc n (bin_sc m True w) \ bintrunc n w" apply (induct n arbitrary: w m) apply simp apply (case_tac w rule: bin_exhaust) apply (case_tac m) apply (auto simp: le_Bits take_bit_Suc mod_2_eq_odd) done 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 \ 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 = bin_sc (pred_numeral k) b (bin_rest w) BIT bin_last w" by (simp add: numeral_eq_Suc) instantiation int :: bit_operations begin definition [iff]: "i !! n \ bin_nth i n" definition "lsb i = i !! 0" for i :: int definition "set_bit i n b = bin_sc n b i" definition "shiftl x n = x * 2 ^ n" for x :: int definition "shiftr x n = x div 2 ^ n" for x :: int definition "msb x \ x < 0" for x :: int instance .. end lemma shiftl_eq_push_bit: \k << n = push_bit n k\ for k :: int by (simp add: shiftl_int_def push_bit_eq_mult) lemma shiftr_eq_drop_bit: \k >> n = drop_bit n k\ for k :: int by (simp add: shiftr_int_def drop_bit_eq_div) subsubsection \Basic simplification rules\ lemmas int_not_def = not_int_def lemma int_not_BIT [simp]: "NOT (w BIT b) = (NOT w) BIT (\ b)" by (simp add: not_int_def Bit_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_and_Bits [simp]: "(x BIT b) AND (y BIT c) = (x AND y) BIT (b \ c)" using and_int_rec [of \x BIT b\ \y BIT c\] by (auto simp add: Bit_B0_2t Bit_B1_2t) 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_or_Bits [simp]: "(x BIT b) OR (y BIT c) = (x OR y) BIT (b \ c)" using or_int_rec [of \x BIT b\ \y BIT c\] by (auto simp add: Bit_B0_2t Bit_B1_2t) lemma int_xor_zero [simp]: "0 XOR x = x" for x :: int by (fact bit.xor_zero_left) lemma int_xor_Bits [simp]: "(x BIT b) XOR (y BIT c) = (x XOR y) BIT ((b \ c) \ \ (b \ c))" using xor_int_rec [of \x BIT b\ \y BIT c\] by (auto simp add: Bit_B0_2t Bit_B1_2t) subsubsection \Binary destructors\ lemma bin_rest_NOT [simp]: "bin_rest (NOT x) = NOT (bin_rest x)" by (fact not_int_div_2) lemma bin_last_NOT [simp]: "bin_last (NOT x) \ \ bin_last x" by simp lemma bin_rest_AND [simp]: "bin_rest (x AND y) = bin_rest x AND bin_rest y" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_last_AND [simp]: "bin_last (x AND y) \ bin_last x \ bin_last y" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_rest_OR [simp]: "bin_rest (x OR y) = bin_rest x OR bin_rest y" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_last_OR [simp]: "bin_last (x OR y) \ bin_last x \ bin_last y" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_rest_XOR [simp]: "bin_rest (x XOR y) = bin_rest x XOR bin_rest y" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_last_XOR [simp]: "bin_last (x XOR y) \ (bin_last x \ bin_last y) \ \ (bin_last x \ bin_last y)" by (cases x rule: bin_exhaust, cases y rule: bin_exhaust) simp lemma bin_nth_ops: "\x y. bin_nth (x AND y) n \ bin_nth x n \ bin_nth y n" "\x y. bin_nth (x OR y) n \ bin_nth x n \ bin_nth y n" "\x y. bin_nth (x XOR y) n \ bin_nth x n \ bin_nth y n" "\x. bin_nth (NOT x) n \ \ bin_nth x n" by (simp_all add: bit_and_iff bit_or_iff bit_xor_iff bit_not_iff) subsubsection \Derived properties\ 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 \Commutativity of the above.\ 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 \Basic properties of logical (bit-wise) operations\ lemma bbw_ao_absorb: "x AND (y OR x) = x \ 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 \ (y AND x) OR x = x" "(y OR x) AND x = x \ x OR (x AND y) = x" "(x OR y) AND x = x \ (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) \ 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 \Simplification with numerals\ text \Cases for \0\ and \-1\ are already covered by other simp rules.\ lemma bin_rest_neg_numeral_BitM [simp]: "bin_rest (- numeral (Num.BitM w)) = - numeral w" by simp lemma bin_last_neg_numeral_BitM [simp]: "bin_last (- numeral (Num.BitM w))" by simp (* FIXME: The rule sets below are very large (24 rules for each operator). Is there a simpler way to do this? *) lemma int_and_numerals [simp]: "numeral (Num.Bit0 x) AND numeral (Num.Bit0 y) = (numeral x AND numeral y) BIT False" "numeral (Num.Bit0 x) AND numeral (Num.Bit1 y) = (numeral x AND numeral y) BIT False" "numeral (Num.Bit1 x) AND numeral (Num.Bit0 y) = (numeral x AND numeral y) BIT False" "numeral (Num.Bit1 x) AND numeral (Num.Bit1 y) = (numeral x AND numeral y) BIT True" "numeral (Num.Bit0 x) AND - numeral (Num.Bit0 y) = (numeral x AND - numeral y) BIT False" "numeral (Num.Bit0 x) AND - numeral (Num.Bit1 y) = (numeral x AND - numeral (y + Num.One)) BIT False" "numeral (Num.Bit1 x) AND - numeral (Num.Bit0 y) = (numeral x AND - numeral y) BIT False" "numeral (Num.Bit1 x) AND - numeral (Num.Bit1 y) = (numeral x AND - numeral (y + Num.One)) BIT True" "- numeral (Num.Bit0 x) AND numeral (Num.Bit0 y) = (- numeral x AND numeral y) BIT False" "- numeral (Num.Bit0 x) AND numeral (Num.Bit1 y) = (- numeral x AND numeral y) BIT False" "- numeral (Num.Bit1 x) AND numeral (Num.Bit0 y) = (- numeral (x + Num.One) AND numeral y) BIT False" "- numeral (Num.Bit1 x) AND numeral (Num.Bit1 y) = (- numeral (x + Num.One) AND numeral y) BIT True" "- numeral (Num.Bit0 x) AND - numeral (Num.Bit0 y) = (- numeral x AND - numeral y) BIT False" "- numeral (Num.Bit0 x) AND - numeral (Num.Bit1 y) = (- numeral x AND - numeral (y + Num.One)) BIT False" "- numeral (Num.Bit1 x) AND - numeral (Num.Bit0 y) = (- numeral (x + Num.One) AND - numeral y) BIT False" "- numeral (Num.Bit1 x) AND - numeral (Num.Bit1 y) = (- numeral (x + Num.One) AND - numeral (y + Num.One)) BIT True" "(1::int) AND numeral (Num.Bit0 y) = 0" "(1::int) AND numeral (Num.Bit1 y) = 1" "(1::int) AND - numeral (Num.Bit0 y) = 0" "(1::int) AND - numeral (Num.Bit1 y) = 1" "numeral (Num.Bit0 x) AND (1::int) = 0" "numeral (Num.Bit1 x) AND (1::int) = 1" "- numeral (Num.Bit0 x) AND (1::int) = 0" "- numeral (Num.Bit1 x) AND (1::int) = 1" by (rule bin_rl_eqI; simp)+ lemma int_or_numerals [simp]: "numeral (Num.Bit0 x) OR numeral (Num.Bit0 y) = (numeral x OR numeral y) BIT False" "numeral (Num.Bit0 x) OR numeral (Num.Bit1 y) = (numeral x OR numeral y) BIT True" "numeral (Num.Bit1 x) OR numeral (Num.Bit0 y) = (numeral x OR numeral y) BIT True" "numeral (Num.Bit1 x) OR numeral (Num.Bit1 y) = (numeral x OR numeral y) BIT True" "numeral (Num.Bit0 x) OR - numeral (Num.Bit0 y) = (numeral x OR - numeral y) BIT False" "numeral (Num.Bit0 x) OR - numeral (Num.Bit1 y) = (numeral x OR - numeral (y + Num.One)) BIT True" "numeral (Num.Bit1 x) OR - numeral (Num.Bit0 y) = (numeral x OR - numeral y) BIT True" "numeral (Num.Bit1 x) OR - numeral (Num.Bit1 y) = (numeral x OR - numeral (y + Num.One)) BIT True" "- numeral (Num.Bit0 x) OR numeral (Num.Bit0 y) = (- numeral x OR numeral y) BIT False" "- numeral (Num.Bit0 x) OR numeral (Num.Bit1 y) = (- numeral x OR numeral y) BIT True" "- numeral (Num.Bit1 x) OR numeral (Num.Bit0 y) = (- numeral (x + Num.One) OR numeral y) BIT True" "- numeral (Num.Bit1 x) OR numeral (Num.Bit1 y) = (- numeral (x + Num.One) OR numeral y) BIT True" "- numeral (Num.Bit0 x) OR - numeral (Num.Bit0 y) = (- numeral x OR - numeral y) BIT False" "- numeral (Num.Bit0 x) OR - numeral (Num.Bit1 y) = (- numeral x OR - numeral (y + Num.One)) BIT True" "- numeral (Num.Bit1 x) OR - numeral (Num.Bit0 y) = (- numeral (x + Num.One) OR - numeral y) BIT True" "- numeral (Num.Bit1 x) OR - numeral (Num.Bit1 y) = (- numeral (x + Num.One) OR - numeral (y + Num.One)) BIT True" "(1::int) OR numeral (Num.Bit0 y) = numeral (Num.Bit1 y)" "(1::int) OR numeral (Num.Bit1 y) = numeral (Num.Bit1 y)" "(1::int) OR - numeral (Num.Bit0 y) = - numeral (Num.BitM y)" "(1::int) OR - numeral (Num.Bit1 y) = - numeral (Num.Bit1 y)" "numeral (Num.Bit0 x) OR (1::int) = numeral (Num.Bit1 x)" "numeral (Num.Bit1 x) OR (1::int) = numeral (Num.Bit1 x)" "- numeral (Num.Bit0 x) OR (1::int) = - numeral (Num.BitM x)" "- numeral (Num.Bit1 x) OR (1::int) = - numeral (Num.Bit1 x)" by (rule bin_rl_eqI; simp)+ lemma int_xor_numerals [simp]: "numeral (Num.Bit0 x) XOR numeral (Num.Bit0 y) = (numeral x XOR numeral y) BIT False" "numeral (Num.Bit0 x) XOR numeral (Num.Bit1 y) = (numeral x XOR numeral y) BIT True" "numeral (Num.Bit1 x) XOR numeral (Num.Bit0 y) = (numeral x XOR numeral y) BIT True" "numeral (Num.Bit1 x) XOR numeral (Num.Bit1 y) = (numeral x XOR numeral y) BIT False" "numeral (Num.Bit0 x) XOR - numeral (Num.Bit0 y) = (numeral x XOR - numeral y) BIT False" "numeral (Num.Bit0 x) XOR - numeral (Num.Bit1 y) = (numeral x XOR - numeral (y + Num.One)) BIT True" "numeral (Num.Bit1 x) XOR - numeral (Num.Bit0 y) = (numeral x XOR - numeral y) BIT True" "numeral (Num.Bit1 x) XOR - numeral (Num.Bit1 y) = (numeral x XOR - numeral (y + Num.One)) BIT False" "- numeral (Num.Bit0 x) XOR numeral (Num.Bit0 y) = (- numeral x XOR numeral y) BIT False" "- numeral (Num.Bit0 x) XOR numeral (Num.Bit1 y) = (- numeral x XOR numeral y) BIT True" "- numeral (Num.Bit1 x) XOR numeral (Num.Bit0 y) = (- numeral (x + Num.One) XOR numeral y) BIT True" "- numeral (Num.Bit1 x) XOR numeral (Num.Bit1 y) = (- numeral (x + Num.One) XOR numeral y) BIT False" "- numeral (Num.Bit0 x) XOR - numeral (Num.Bit0 y) = (- numeral x XOR - numeral y) BIT False" "- numeral (Num.Bit0 x) XOR - numeral (Num.Bit1 y) = (- numeral x XOR - numeral (y + Num.One)) BIT True" "- numeral (Num.Bit1 x) XOR - numeral (Num.Bit0 y) = (- numeral (x + Num.One) XOR - numeral y) BIT True" "- numeral (Num.Bit1 x) XOR - numeral (Num.Bit1 y) = (- numeral (x + Num.One) XOR - numeral (y + Num.One)) BIT False" "(1::int) XOR numeral (Num.Bit0 y) = numeral (Num.Bit1 y)" "(1::int) XOR numeral (Num.Bit1 y) = numeral (Num.Bit0 y)" "(1::int) XOR - numeral (Num.Bit0 y) = - numeral (Num.BitM y)" "(1::int) XOR - numeral (Num.Bit1 y) = - numeral (Num.Bit0 (y + Num.One))" "numeral (Num.Bit0 x) XOR (1::int) = numeral (Num.Bit1 x)" "numeral (Num.Bit1 x) XOR (1::int) = numeral (Num.Bit0 x)" "- numeral (Num.Bit0 x) XOR (1::int) = - numeral (Num.BitM x)" "- numeral (Num.Bit1 x) XOR (1::int) = - numeral (Num.Bit0 (x + Num.One))" by (rule bin_rl_eqI; simp)+ subsubsection \Interactions with arithmetic\ lemma plus_and_or [rule_format]: "\y::int. (x AND y) + (x OR y) = x + y" apply (induct x rule: bin_induct) apply clarsimp apply clarsimp apply clarsimp apply (case_tac y rule: bin_exhaust) apply clarsimp apply (unfold Bit_def) apply clarsimp apply (erule_tac x = "x" in allE) apply simp done lemma le_int_or: "bin_sign y = 0 \ x \ x OR y" for x y :: int apply (induct y arbitrary: x rule: bin_induct) apply clarsimp apply clarsimp apply (case_tac x rule: bin_exhaust) apply (case_tac b) apply (case_tac [!] bit) apply (auto simp: le_Bits) done lemmas int_and_le = xtrans(3) [OF bbw_ao_absorbs (2) [THEN conjunct2, symmetric] le_int_or] text \Interaction between bit-wise and arithmetic: good example of \bin_induction\.\ lemma bin_add_not: "x + NOT x = (-1::int)" apply (induct x rule: bin_induct) apply clarsimp apply clarsimp apply (case_tac bit, auto) done lemma mod_BIT: "bin BIT bit mod 2 ^ Suc n = (bin mod 2 ^ n) BIT bit" for bit proof - have "2 * (bin mod 2 ^ n) + 1 = (2 * bin mod 2 ^ Suc n) + 1" by (simp add: mod_mult_mult1) also have "\ = ((2 * bin mod 2 ^ Suc n) + 1) mod 2 ^ Suc n" by (simp add: ac_simps pos_zmod_mult_2) also have "\ = (2 * bin + 1) mod 2 ^ Suc n" by (simp only: mod_simps) finally show ?thesis by (auto simp add: Bit_def) qed lemma AND_mod: "x AND 2 ^ n - 1 = x mod 2 ^ n" for x :: int proof (induct x arbitrary: n rule: bin_induct) case 1 then show ?case by simp next case 2 then show ?case by (simp, simp add: m1mod2k) next case (3 bin bit) show ?case proof (cases n) case 0 then show ?thesis by simp next case (Suc m) with 3 show ?thesis by (simp only: power_BIT mod_BIT int_and_Bits) simp qed qed subsubsection \Comparison\ lemma AND_lower [simp]: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" shows "0 \ x AND y" using assms proof (induct x arbitrary: y rule: bin_induct) case 1 then show ?case by simp next case 2 then show ?case by (simp only: Min_def) next case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) then have "0 \ bin AND bin'" by (rule 3) with 1 show ?thesis by simp qed qed lemma OR_lower [simp]: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" "0 \ y" shows "0 \ x OR y" using assms proof (induct x arbitrary: y rule: bin_induct) case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) moreover from 1 3 have "0 \ bin'" by (cases bit') (simp_all add: Bit_def) ultimately have "0 \ bin OR bin'" by (rule 3) with 1 show ?thesis by simp qed qed simp_all lemma XOR_lower [simp]: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" "0 \ y" shows "0 \ x XOR y" using assms proof (induct x arbitrary: y rule: bin_induct) case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) moreover from 1 3 have "0 \ bin'" by (cases bit') (simp_all add: Bit_def) ultimately have "0 \ bin XOR bin'" by (rule 3) with 1 show ?thesis by simp qed next case 2 then show ?case by (simp only: Min_def) qed simp lemma AND_upper1 [simp]: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" shows "x AND y \ x" using assms proof (induct x arbitrary: y rule: bin_induct) case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) then have "bin AND bin' \ bin" by (rule 3) with 1 show ?thesis by simp (simp add: Bit_def) qed next case 2 then show ?case by (simp only: Min_def) qed simp lemmas AND_upper1' [simp] = order_trans [OF AND_upper1] \<^marker>\contributor \Stefan Berghofer\\ lemmas AND_upper1'' [simp] = order_le_less_trans [OF AND_upper1] \<^marker>\contributor \Stefan Berghofer\\ lemma AND_upper2 [simp]: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ y" shows "x AND y \ y" using assms proof (induct y arbitrary: x rule: bin_induct) case 1 then show ?case by simp next case 2 then show ?case by (simp only: Min_def) next case (3 bin bit) show ?case proof (cases x rule: bin_exhaust) case (1 bin' bit') from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) then have "bin' AND bin \ bin" by (rule 3) with 1 show ?thesis by simp (simp add: Bit_def) qed qed lemmas AND_upper2' [simp] = order_trans [OF AND_upper2] \<^marker>\contributor \Stefan Berghofer\\ lemmas AND_upper2'' [simp] = order_le_less_trans [OF AND_upper2] \<^marker>\contributor \Stefan Berghofer\\ lemma OR_upper: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" "x < 2 ^ n" "y < 2 ^ n" shows "x OR y < 2 ^ n" using assms proof (induct x arbitrary: y n rule: bin_induct) case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') show ?thesis proof (cases n) case 0 with 3 have "bin BIT bit = 0" by (simp add: Bit_def) then have "bin = 0" and "\ bit" by (auto simp add: Bit_def split: if_splits) arith then show ?thesis using 0 1 \y < 2 ^ n\ by simp next case (Suc m) from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) moreover from 3 Suc have "bin < 2 ^ m" by (cases bit) (simp_all add: Bit_def) moreover from 1 3 Suc have "bin' < 2 ^ m" by (cases bit') (simp_all add: Bit_def) ultimately have "bin OR bin' < 2 ^ m" by (rule 3) with 1 Suc show ?thesis by simp (simp add: Bit_def) qed qed qed simp_all lemma XOR_upper: \<^marker>\contributor \Stefan Berghofer\\ fixes x y :: int assumes "0 \ x" "x < 2 ^ n" "y < 2 ^ n" shows "x XOR y < 2 ^ n" using assms proof (induct x arbitrary: y n rule: bin_induct) case 1 then show ?case by simp next case 2 then show ?case by (simp only: Min_def) next case (3 bin bit) show ?case proof (cases y rule: bin_exhaust) case (1 bin' bit') show ?thesis proof (cases n) case 0 with 3 have "bin BIT bit = 0" by (simp add: Bit_def) then have "bin = 0" and "\ bit" by (auto simp add: Bit_def split: if_splits) arith then show ?thesis using 0 1 \y < 2 ^ n\ by simp next case (Suc m) from 3 have "0 \ bin" by (cases bit) (simp_all add: Bit_def) moreover from 3 Suc have "bin < 2 ^ m" by (cases bit) (simp_all add: Bit_def) moreover from 1 3 Suc have "bin' < 2 ^ m" by (cases bit') (simp_all add: Bit_def) ultimately have "bin XOR bin' < 2 ^ m" by (rule 3) with 1 Suc show ?thesis by simp (simp add: Bit_def) qed qed qed subsubsection \Truncating results of bit-wise operations\ lemma bin_trunc_ao: "bintrunc n x AND bintrunc n y = bintrunc n (x AND y)" "bintrunc n x OR bintrunc n y = bintrunc n (x OR y)" by (auto simp add: bin_eq_iff bin_nth_ops nth_bintr) lemma bin_trunc_xor: "bintrunc n (bintrunc n x XOR bintrunc n y) = bintrunc n (x XOR y)" by (auto simp add: bin_eq_iff bin_nth_ops nth_bintr) lemma bin_trunc_not: "bintrunc n (NOT (bintrunc n x)) = bintrunc n (NOT x)" by (auto simp add: bin_eq_iff bin_nth_ops nth_bintr) text \Want theorems of the form of \bin_trunc_xor\.\ lemma bintr_bintr_i: "x = bintrunc n y \ bintrunc n x = bintrunc 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 \More lemmas\ lemma not_int_cmp_0 [simp]: fixes i :: int shows "0 < NOT i \ i < -1" "0 \ NOT i \ i < 0" "NOT i < 0 \ i \ 0" "NOT i \ 0 \ i \ -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]: \x AND y < 0 \ x < 0 \ y < 0\ for x y :: int by (fact and_negative_int_iff) lemma int_and_ge0 [simp]: \x AND y \ 0 \ x \ 0 \ y \ 0\ 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]: \x OR y < 0 \ x < 0 \ y < 0\ for x y :: int by (fact or_negative_int_iff) lemma int_or_ge0 [simp]: \x OR y \ 0 \ x \ 0 \ y \ 0\ for x y :: int by (fact or_nonnegative_int_iff) lemma int_xor_lt0 [simp]: \x XOR y < 0 \ (x < 0) \ (y < 0)\ for x y :: int by (fact xor_negative_int_iff) lemma int_xor_ge0 [simp]: \x XOR y \ 0 \ (x \ 0 \ y \ 0)\ for x y :: int by (fact xor_nonnegative_int_iff) lemma even_conv_AND: \even i \ i AND 1 = 0\ for i :: int by (simp add: and_one_eq mod2_eq_if) lemma bin_last_conv_AND: "bin_last i \ i AND 1 \ 0" by (simp add: and_one_eq mod2_eq_if) lemma bitval_bin_last: "of_bool (bin_last 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 minus_BIT_0: fixes x y :: int shows "x BIT b - y BIT False = (x - y) BIT b" by(simp add: Bit_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 \Setting and clearing bits\ lemma int_lsb_BIT [simp]: fixes x :: int shows "lsb (x BIT b) \ b" by(simp add: lsb_int_def) lemma bin_last_conv_lsb: "bin_last = lsb" by(clarsimp simp add: lsb_int_def fun_eq_iff) lemma int_lsb_numeral [simp]: "lsb (0 :: int) = False" "lsb (1 :: int) = True" "lsb (Numeral1 :: int) = True" "lsb (- 1 :: int) = True" "lsb (- Numeral1 :: int) = True" "lsb (numeral (num.Bit0 w) :: int) = False" "lsb (numeral (num.Bit1 w) :: int) = True" "lsb (- numeral (num.Bit0 w) :: int) = False" "lsb (- numeral (num.Bit1 w) :: int) = True" by (simp_all add: lsb_int_def) lemma int_set_bit_0 [simp]: fixes x :: int shows "set_bit x 0 b = bin_rest x BIT b" by(auto simp add: set_bit_int_def intro: bin_rl_eqI) lemma int_set_bit_Suc: fixes x :: int shows "set_bit x (Suc n) b = set_bit (bin_rest x) n b BIT bin_last x" by(auto simp add: set_bit_int_def twice_conv_BIT intro: bin_rl_eqI) lemma bin_last_set_bit: "bin_last (set_bit x n b) = (if n > 0 then bin_last x else b)" by(cases n)(simp_all add: int_set_bit_Suc) lemma bin_rest_set_bit: "bin_rest (set_bit x n b) = (if n > 0 then set_bit (bin_rest x) (n - 1) b else bin_rest x)" by(cases n)(simp_all add: int_set_bit_Suc) lemma int_set_bit_numeral: fixes x :: int shows "set_bit x (numeral w) b = set_bit (bin_rest x) (pred_numeral w) b BIT bin_last x" by(simp add: set_bit_int_def) lemmas int_set_bit_numerals [simp] = int_set_bit_numeral[where x="numeral w'"] int_set_bit_numeral[where x="- numeral w'"] int_set_bit_numeral[where x="Numeral1"] int_set_bit_numeral[where x="1"] int_set_bit_numeral[where x="0"] int_set_bit_Suc[where x="numeral w'"] int_set_bit_Suc[where x="- numeral w'"] int_set_bit_Suc[where x="Numeral1"] int_set_bit_Suc[where x="1"] int_set_bit_Suc[where x="0"] for w' lemma int_shiftl_BIT: fixes x :: int shows int_shiftl0 [simp]: "x << 0 = x" and int_shiftl_Suc [simp]: "x << Suc n = (x << n) BIT False" by(auto simp add: shiftl_int_def Bit_def) lemma int_0_shiftl [simp]: "0 << n = (0 :: int)" by(induct n) simp_all lemma bin_last_shiftl: "bin_last (x << n) \ n = 0 \ bin_last x" by(cases n)(simp_all) lemma bin_rest_shiftl: "bin_rest (x << n) = (if n > 0 then x << (n - 1) else bin_rest x)" by(cases n)(simp_all) lemma bin_nth_shiftl [simp]: "bin_nth (x << n) m \ n \ m \ bin_nth x (m - n)" proof(induct n arbitrary: x m) case (Suc n) thus ?case by(cases m) simp_all qed simp lemma int_shiftr_BIT [simp]: fixes x :: int shows int_shiftr0: "x >> 0 = x" and int_shiftr_Suc: "x BIT b >> Suc n = x >> n" proof - show "x >> 0 = x" by (simp add: shiftr_int_def) show "x BIT b >> Suc n = x >> n" by (cases b) (simp_all add: shiftr_int_def Bit_def add.commute pos_zdiv_mult_2) qed lemma bin_last_shiftr: "bin_last (x >> n) \ x !! n" proof(induct n arbitrary: x) case 0 thus ?case by simp next case (Suc n) thus ?case by(cases x rule: bin_exhaust) simp qed lemma bin_rest_shiftr [simp]: "bin_rest (x >> n) = x >> Suc n" proof(induct n arbitrary: x) case 0 thus ?case by(cases x rule: bin_exhaust) auto next case (Suc n) thus ?case by(cases x rule: bin_exhaust) auto qed lemma bin_nth_shiftr [simp]: "bin_nth (x >> n) m = bin_nth x (n + m)" proof(induct n arbitrary: x m) case (Suc n) thus ?case by(cases x rule: bin_exhaust) simp_all qed simp lemma bin_nth_conv_AND: fixes x :: int shows "bin_nth x n \ x AND (1 << n) \ 0" proof(induct n arbitrary: x) case 0 thus ?case by(simp add: int_and_1 bin_last_def) next case (Suc n) thus ?case by(cases x rule: bin_exhaust)(simp_all add: bin_nth_ops Bit_eq_0_iff) qed 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 Bit_def 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 \ 0 \ i \ 0" by(induct n) simp_all lemma shiftl_lt_0 [simp]: fixes i :: int shows "i << n < 0 \ i < 0" by (metis not_le shiftl_ge_0) lemma int_shiftl_test_bit: "(n << i :: int) !! m \ m \ i \ n !! (m - i)" proof(induction i) case (Suc n) thus ?case by(cases m) simp_all qed 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 \ 0 \ i \ 0" proof(induct n arbitrary: i) case (Suc n) thus ?case by(cases i rule: bin_exhaust) simp_all qed simp lemma int_shiftr_lt_0 [simp]: fixes i :: int shows "i >> n < 0 \ 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 only: numeral_One expand_BIT numeral_eq_Suc int_shiftr_Suc BIT_special_simps(2)[symmetric] int_0shiftr add_One uminus_Bit_eq) (simp_all add: add_One) 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 only: One_nat_def[symmetric] numeral_One[symmetric] int_shiftr_numeral pred_numeral_simps int_shiftr0) 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 "bin_nth (x - y) m = bin_nth x m" using sign m x unfolding y proof(induction m arbitrary: x y n) case 0 thus ?case by (simp add: bin_last_def shiftl_int_def) next case (Suc m) from \Suc m < n\ obtain n' where [simp]: "n = Suc n'" by(cases n) auto obtain x' b where [simp]: "x = x' BIT b" by(cases x rule: bin_exhaust) from \bin_sign x = 0\ have "bin_sign x' = 0" by simp moreover from \x < 1 << n\ have "x' < 1 << n'" by(cases b)(simp_all add: Bit_def shiftl_int_def) moreover have "(2 * x' + of_bool b - 2 * 2 ^ n') div 2 = x' + (- (2 ^ n') + of_bool b div 2)" by(simp only: add_diff_eq[symmetric] add.commute div_mult_self2[OF zero_neq_numeral[symmetric]]) ultimately show ?case using Suc.IH[of x' n'] Suc.prems by (clarsimp simp add: Bit_def shiftl_int_def bit_Suc) 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)+ lemma msb_conv_bin_sign: "msb x \ bin_sign x = -1" by(simp add: bin_sign_def not_le msb_int_def) lemma msb_BIT [simp]: "msb (x BIT b) = msb x" by(simp add: msb_int_def) lemma msb_bin_rest [simp]: "msb (bin_rest x) = msb x" by(simp add: msb_int_def) lemma int_msb_and [simp]: "msb ((x :: int) AND y) \ msb x \ msb y" by(simp add: msb_int_def) lemma int_msb_or [simp]: "msb ((x :: int) OR y) \ msb x \ msb y" by(simp add: msb_int_def) lemma int_msb_xor [simp]: "msb ((x :: int) XOR y) \ msb x \ msb y" by(simp add: msb_int_def) lemma int_msb_not [simp]: "msb (NOT (x :: int)) \ \ msb x" by(simp add: msb_int_def not_less) lemma msb_shiftl [simp]: "msb ((x :: int) << n) \ msb x" by(simp add: msb_int_def) lemma msb_shiftr [simp]: "msb ((x :: int) >> r) \ msb x" by(simp add: msb_int_def) lemma msb_bin_sc [simp]: "msb (bin_sc n b x) \ msb x" by(simp add: msb_conv_bin_sign) lemma msb_set_bit [simp]: "msb (set_bit (x :: int) n b) \ msb x" by(simp add: msb_conv_bin_sign set_bit_int_def) lemma msb_0 [simp]: "msb (0 :: int) = False" by(simp add: msb_int_def) lemma msb_1 [simp]: "msb (1 :: int) = False" by(simp add: msb_int_def) lemma msb_numeral [simp]: "msb (numeral n :: int) = False" "msb (- numeral n :: int) = True" by(simp_all add: msb_int_def) subsection \Semantic interpretation of \<^typ>\bool list\ as \<^typ>\int\\ lemma bin_bl_bin': "bl_to_bin (bin_to_bl_aux n w bs) = bl_to_bin_aux bs (bintrunc n w)" by (induct n arbitrary: w bs) (auto simp: bl_to_bin_def take_bit_Suc Bit_def ac_simps mod_2_eq_odd) lemma bin_bl_bin [simp]: "bl_to_bin (bin_to_bl n w) = bintrunc 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 \ m \ bin_to_bl n (bintrunc 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 (bintrunc 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 (bintrunc 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 (induct bs arbitrary: w) auto 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 (sbintrunc n w) = -1)" apply (induct n arbitrary: w bs) apply clarsimp apply (cases w rule: bin_exhaust) apply simp done lemma bl_sbin_sign: "hd (bin_to_bl (Suc n) w) = (bin_sign (sbintrunc n w) = -1)" unfolding bin_to_bl_def by (rule bl_sbin_sign_aux) lemma bin_nth_of_bl_aux: "bin_nth (bl_to_bin_aux bl w) n = (n < size bl \ rev bl ! n \ n \ length bl \ bin_nth w (n - size bl))" apply (induct bl arbitrary: w) apply clarsimp apply clarsimp apply (cut_tac x=n and y="size bl" in linorder_less_linear) apply (erule disjE, simp add: nth_append)+ apply auto done lemma bin_nth_of_bl: "bin_nth (bl_to_bin bl) n = (n < length bl \ rev bl ! n)" by (simp add: bl_to_bin_def bin_nth_of_bl_aux) lemma bin_nth_bl: "n < m \ bin_nth 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 \ (bin_to_bl_aux m w bl) ! n = (if n < m then bin_nth w (m - 1 - n) else bl ! (n - m))" apply (induct m arbitrary: w n bl) apply clarsimp apply clarsimp apply (case_tac w rule: bin_exhaust) apply simp done lemma nth_bin_to_bl: "n < m \ (bin_to_bl m w) ! n = bin_nth w (m - Suc n)" by (simp add: bin_to_bl_def nth_bin_to_bl_aux) lemma bl_to_bin_lt2p_aux: "bl_to_bin_aux bs w < (w + 1) * (2 ^ length bs)" apply (induct bs arbitrary: w) apply clarsimp apply clarsimp apply (drule meta_spec, erule xtrans(8) [rotated], simp add: Bit_def)+ done 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 \ w * (2 ^ length bs)" apply (induct bs arbitrary: w) apply clarsimp apply clarsimp apply (drule meta_spec, erule order_trans [rotated], simp add: Bit_B0_2t Bit_B1_2t algebra_simps)+ apply (simp add: Bit_def) done lemma bl_to_bin_ge0: "bl_to_bin bs \ 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) (bin_rest w)" apply (unfold bin_to_bl_def) apply (cases w rule: bin_exhaust) 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) (bin_rest (bl_to_bin bl))" using butlast_rest_bin [where w="bl_to_bin bl" and n="length bl"] by simp lemma butlast_rest_bl2bin_aux: "bl \ [] \ bl_to_bin_aux (butlast bl) w = bin_rest (bl_to_bin_aux bl w)" by (induct bl arbitrary: w) auto lemma butlast_rest_bl2bin: "bl_to_bin (butlast bl) = bin_rest (bl_to_bin bl)" by (cases bl) (auto simp: bl_to_bin_def butlast_rest_bl2bin_aux) lemma trunc_bl2bin_aux: "bintrunc m (bl_to_bin_aux bl w) = bl_to_bin_aux (drop (length bl - m) bl) (bintrunc (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 Bit_def ac_simps) qed qed lemma trunc_bl2bin: "bintrunc 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]: "bintrunc (length bl) (bl_to_bin bl) = bl_to_bin bl" by (simp add: trunc_bl2bin) lemma bl2bin_drop: "bl_to_bin (drop k bl) = bintrunc (length bl - k) (bl_to_bin bl)" apply (rule trans) prefer 2 apply (rule trunc_bl2bin [symmetric]) apply (cases "k \ length bl") apply auto done lemma take_rest_power_bin: "m \ n \ take m (bin_to_bl n w) = bin_to_bl m ((bin_rest ^^ (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 \ last xs \ bin_last (bl_to_bin_aux xs w)" by (induct xs arbitrary: w) auto lemma last_bin_last: "size xs > 0 \ last xs \ bin_last (bl_to_bin xs)" unfolding bl_to_bin_def by (erule last_bin_last') lemma bin_last_last: "bin_last w \ 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 (induct n arbitrary: m bin bs, clarsimp) apply clarsimp apply (case_tac bin rule: bin_exhaust) apply (case_tac "m \ n", simp) apply (case_tac "m - n", simp) apply simp apply (rule_tac f = "\nat. drop nat bs" in arg_cong) apply simp 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) \ 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 \ 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 \ bin_split n c = (a, b) \ bin_to_bl m a = take m (bin_to_bl k c)" using bin_split_take by simp 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 nth_rev 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_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_bin_bl_rtf takefill_alt rev_take) lemma bl_to_bin_aux_cat: "\nv v. bl_to_bin_aux bs (bin_cat w nv v) = bin_cat w (nv + length bs) (bl_to_bin_aux bs v)" by (induct bs) (simp, simp add: bin_cat_Suc_Bit [symmetric] del: bin_cat.simps) lemma bin_to_bl_aux_cat: "\w bs. bin_to_bl_aux (nv + nw) (bin_cat v nw w) bs = bin_to_bl_aux nv v (bin_to_bl_aux nw w bs)" by (induct nw) auto lemma bl_to_bin_aux_alt: "bl_to_bin_aux bs w = bin_cat w (length bs) (bl_to_bin bs)" 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) (bin_cat v nw w) = 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) = bin_cat (bl_to_bin bsa) (length bs) (bl_to_bin bs)" by (simp only: bl_to_bin_aux_app_cat bl_to_bin_def) lemma bin_to_bl_cat_app: "bin_to_bl (n + nw) (bin_cat w nw wa) = bin_to_bl n w @ bin_to_bl nw wa" by (simp only: bin_to_bl_def bin_to_bl_aux_cat_app) text \\bl_to_bin_app_cat_alt\ and \bl_to_bin_app_cat\ are easily interderivable.\ lemma bl_to_bin_app_cat_alt: "bin_cat (bl_to_bin cs) n w = 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 add: Bit_B0_2t Bit_B1_2t) done primrec rbl_succ :: "bool list \ 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 \ 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 \ bool list \ bool list" where \ \result is length of first arg, second arg may be longer\ Nil: "rbl_add Nil x = Nil" | Cons: "rbl_add (y # ys) x = (let ws = rbl_add ys (tl x) in (y \ hd x) # (if hd x \ y then rbl_succ ws else ws))" primrec rbl_mult :: "bool list \ bool list \ bool list" where \ \result is length of first arg, second arg may be longer\ 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 \ length bla \ 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 \ length bla \ 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 \ length bla \ 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 \ length bla \ 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)) = (\ws. length ws = length ys \ ws = rbl_add ys xs \ (y \ ((x \ P (False # rbl_succ ws)) \ (\ x \ P (True # ws)))) \ (\ y \ P (x # ws)))" by (cases y) (auto simp: Let_def) lemma rbl_mult_split: "P (rbl_mult (y # ys) xs) = (\ws. length ws = Suc (length ys) \ ws = False # rbl_mult ys xs \ (y \ P (rbl_add ws xs)) \ (\ y \ 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))" apply (unfold bin_to_bl_def) apply (induct n arbitrary: bin) apply simp apply clarsimp apply (case_tac bin rule: bin_exhaust) apply (case_tac b) apply (clarsimp simp: bin_to_bl_aux_alt)+ done 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 (induct n arbitrary: bin) apply simp apply clarsimp apply (case_tac bin rule: bin_exhaust) apply (case_tac b) apply (clarsimp simp: bin_to_bl_aux_alt)+ done lemma rbl_add: "\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 \ n \ 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 \ length bl \ 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 \ 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) (x BIT b))" 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 apply (unfold bin_to_bl_def) 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: bin_to_bl_aux_alt Let_def) apply (auto simp: rbbl_Cons rbl_mult_Suc rbl_add) done lemma sclem: "size (concat (map (bin_to_bl n) xs)) = length xs * n" by (induct xs) auto lemma bin_cat_foldl_lem: "foldl (\u. bin_cat u n) x xs = bin_cat x (size xs * n) (foldl (\u. bin_cat u n) y xs)" 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 = "bin_cat y n a" in meta_spec) apply (simp add: bin_cat_assoc_sym min.absorb2) done lemma bin_rcat_bl: "bin_rcat n wl = bl_to_bin (concat (map (bin_to_bl n) wl))" apply (unfold bin_rcat_def) 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: "bin_last (bl_to_bin bs) \ bs \ [] \ last bs" by(cases "bs = []")(auto simp add: bl_to_bin_def last_bin_last'[where w=0]) lemma bin_rest_bl_to_bin: "bin_rest (bl_to_bin bs) = 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 (\x y. x \ y) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v XOR w) (map2 (\x y. x \ y) bs cs)" apply (induct n arbitrary: v w bs cs) apply simp apply (case_tac v rule: bin_exhaust) apply (case_tac w rule: bin_exhaust) apply clarsimp apply (case_tac b) apply auto done lemma bl_or_aux_bin: "map2 (\) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v OR w) (map2 (\) bs cs)" apply (induct n arbitrary: v w bs cs) apply simp apply (case_tac v rule: bin_exhaust) apply (case_tac w rule: bin_exhaust) apply clarsimp done lemma bl_and_aux_bin: "map2 (\) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v AND w) (map2 (\) bs cs)" apply (induct n arbitrary: v w bs cs) apply simp apply (case_tac v rule: bin_exhaust) apply (case_tac w rule: bin_exhaust) apply clarsimp done 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 (\) (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 (\) (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 (\) (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) end