diff -r 17e1085d07b2 -r df789294c77a src/HOL/Word/BinOperations.thy --- a/src/HOL/Word/BinOperations.thy Wed Jun 30 16:41:03 2010 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,638 +0,0 @@ -(* - Author: Jeremy Dawson and Gerwin Klein, NICTA - - definition and basic theorems for bit-wise logical operations - for integers expressed using Pls, Min, BIT, - and converting them to and from lists of bools -*) - -header {* Bitwise Operations on Binary Integers *} - -theory BinOperations -imports Bit_Operations BinGeneral -begin - -subsection {* Logical operations *} - -text "bit-wise logical operations on the int type" - -instantiation int :: bit -begin - -definition - int_not_def [code del]: "bitNOT = bin_rec Int.Min Int.Pls - (\w b s. s BIT (NOT b))" - -definition - int_and_def [code del]: "bitAND = bin_rec (\x. Int.Pls) (\y. y) - (\w b s y. s (bin_rest y) BIT (b AND bin_last y))" - -definition - int_or_def [code del]: "bitOR = bin_rec (\x. x) (\y. Int.Min) - (\w b s y. s (bin_rest y) BIT (b OR bin_last y))" - -definition - int_xor_def [code del]: "bitXOR = bin_rec (\x. x) bitNOT - (\w b s y. s (bin_rest y) BIT (b XOR bin_last y))" - -instance .. - -end - -lemma int_not_simps [simp]: - "NOT Int.Pls = Int.Min" - "NOT Int.Min = Int.Pls" - "NOT (Int.Bit0 w) = Int.Bit1 (NOT w)" - "NOT (Int.Bit1 w) = Int.Bit0 (NOT w)" - "NOT (w BIT b) = (NOT w) BIT (NOT b)" - unfolding int_not_def by (simp_all add: bin_rec_simps) - -declare int_not_simps(1-4) [code] - -lemma int_xor_Pls [simp, code]: - "Int.Pls XOR x = x" - unfolding int_xor_def by (simp add: bin_rec_PM) - -lemma int_xor_Min [simp, code]: - "Int.Min XOR x = NOT x" - unfolding int_xor_def by (simp add: bin_rec_PM) - -lemma int_xor_Bits [simp]: - "(x BIT b) XOR (y BIT c) = (x XOR y) BIT (b XOR c)" - apply (unfold int_xor_def) - apply (rule bin_rec_simps (1) [THEN fun_cong, THEN trans]) - apply (rule ext, simp) - prefer 2 - apply simp - apply (rule ext) - apply (simp add: int_not_simps [symmetric]) - done - -lemma int_xor_Bits2 [simp, code]: - "(Int.Bit0 x) XOR (Int.Bit0 y) = Int.Bit0 (x XOR y)" - "(Int.Bit0 x) XOR (Int.Bit1 y) = Int.Bit1 (x XOR y)" - "(Int.Bit1 x) XOR (Int.Bit0 y) = Int.Bit1 (x XOR y)" - "(Int.Bit1 x) XOR (Int.Bit1 y) = Int.Bit0 (x XOR y)" - unfolding BIT_simps [symmetric] int_xor_Bits by simp_all - -lemma int_xor_x_simps': - "w XOR (Int.Pls BIT 0) = w" - "w XOR (Int.Min BIT 1) = NOT w" - apply (induct w rule: bin_induct) - apply simp_all[4] - apply (unfold int_xor_Bits) - apply clarsimp+ - done - -lemma int_xor_extra_simps [simp, code]: - "w XOR Int.Pls = w" - "w XOR Int.Min = NOT w" - using int_xor_x_simps' by simp_all - -lemma int_or_Pls [simp, code]: - "Int.Pls OR x = x" - by (unfold int_or_def) (simp add: bin_rec_PM) - -lemma int_or_Min [simp, code]: - "Int.Min OR x = Int.Min" - by (unfold int_or_def) (simp add: bin_rec_PM) - -lemma int_or_Bits [simp]: - "(x BIT b) OR (y BIT c) = (x OR y) BIT (b OR c)" - unfolding int_or_def by (simp add: bin_rec_simps) - -lemma int_or_Bits2 [simp, code]: - "(Int.Bit0 x) OR (Int.Bit0 y) = Int.Bit0 (x OR y)" - "(Int.Bit0 x) OR (Int.Bit1 y) = Int.Bit1 (x OR y)" - "(Int.Bit1 x) OR (Int.Bit0 y) = Int.Bit1 (x OR y)" - "(Int.Bit1 x) OR (Int.Bit1 y) = Int.Bit1 (x OR y)" - unfolding BIT_simps [symmetric] int_or_Bits by simp_all - -lemma int_or_x_simps': - "w OR (Int.Pls BIT 0) = w" - "w OR (Int.Min BIT 1) = Int.Min" - apply (induct w rule: bin_induct) - apply simp_all[4] - apply (unfold int_or_Bits) - apply clarsimp+ - done - -lemma int_or_extra_simps [simp, code]: - "w OR Int.Pls = w" - "w OR Int.Min = Int.Min" - using int_or_x_simps' by simp_all - -lemma int_and_Pls [simp, code]: - "Int.Pls AND x = Int.Pls" - unfolding int_and_def by (simp add: bin_rec_PM) - -lemma int_and_Min [simp, code]: - "Int.Min AND x = x" - unfolding int_and_def by (simp add: bin_rec_PM) - -lemma int_and_Bits [simp]: - "(x BIT b) AND (y BIT c) = (x AND y) BIT (b AND c)" - unfolding int_and_def by (simp add: bin_rec_simps) - -lemma int_and_Bits2 [simp, code]: - "(Int.Bit0 x) AND (Int.Bit0 y) = Int.Bit0 (x AND y)" - "(Int.Bit0 x) AND (Int.Bit1 y) = Int.Bit0 (x AND y)" - "(Int.Bit1 x) AND (Int.Bit0 y) = Int.Bit0 (x AND y)" - "(Int.Bit1 x) AND (Int.Bit1 y) = Int.Bit1 (x AND y)" - unfolding BIT_simps [symmetric] int_and_Bits by simp_all - -lemma int_and_x_simps': - "w AND (Int.Pls BIT 0) = Int.Pls" - "w AND (Int.Min BIT 1) = w" - apply (induct w rule: bin_induct) - apply simp_all[4] - apply (unfold int_and_Bits) - apply clarsimp+ - done - -lemma int_and_extra_simps [simp, code]: - "w AND Int.Pls = Int.Pls" - "w AND Int.Min = w" - using int_and_x_simps' by simp_all - -(* commutativity of the above *) -lemma bin_ops_comm: - shows - int_and_comm: "!!y::int. x AND y = y AND x" and - int_or_comm: "!!y::int. x OR y = y OR x" and - int_xor_comm: "!!y::int. x XOR y = y XOR x" - apply (induct x rule: bin_induct) - apply simp_all[6] - apply (case_tac y rule: bin_exhaust, simp add: bit_ops_comm)+ - done - -lemma bin_ops_same [simp]: - "(x::int) AND x = x" - "(x::int) OR x = x" - "(x::int) XOR x = Int.Pls" - by (induct x rule: bin_induct) auto - -lemma int_not_not [simp]: "NOT (NOT (x::int)) = x" - by (induct x rule: bin_induct) auto - -lemmas bin_log_esimps = - int_and_extra_simps int_or_extra_simps int_xor_extra_simps - int_and_Pls int_and_Min int_or_Pls int_or_Min int_xor_Pls int_xor_Min - -(* basic properties of logical (bit-wise) operations *) - -lemma bbw_ao_absorb: - "!!y::int. x AND (y OR x) = x & x OR (y AND x) = x" - apply (induct x rule: bin_induct) - apply auto - apply (case_tac [!] y rule: bin_exhaust) - apply auto - apply (case_tac [!] bit) - apply auto - done - -lemma bbw_ao_absorbs_other: - "x AND (x OR y) = x \ (y AND x) OR x = (x::int)" - "(y OR x) AND x = x \ x OR (x AND y) = (x::int)" - "(x OR y) AND x = x \ (x AND y) OR x = (x::int)" - apply (auto simp: bbw_ao_absorb int_or_comm) - apply (subst int_or_comm) - apply (simp add: bbw_ao_absorb) - apply (subst int_and_comm) - apply (subst int_or_comm) - apply (simp add: bbw_ao_absorb) - apply (subst int_and_comm) - apply (simp add: bbw_ao_absorb) - done - -lemmas bbw_ao_absorbs [simp] = bbw_ao_absorb bbw_ao_absorbs_other - -lemma int_xor_not: - "!!y::int. (NOT x) XOR y = NOT (x XOR y) & - x XOR (NOT y) = NOT (x XOR y)" - apply (induct x rule: bin_induct) - apply auto - apply (case_tac y rule: bin_exhaust, auto, - case_tac b, auto)+ - done - -lemma bbw_assocs': - "!!y z::int. (x AND y) AND z = x AND (y AND z) & - (x OR y) OR z = x OR (y OR z) & - (x XOR y) XOR z = x XOR (y XOR z)" - apply (induct x rule: bin_induct) - apply (auto simp: int_xor_not) - apply (case_tac [!] y rule: bin_exhaust) - apply (case_tac [!] z rule: bin_exhaust) - apply (case_tac [!] bit) - apply (case_tac [!] b) - apply (auto simp del: BIT_simps) - done - -lemma int_and_assoc: - "(x AND y) AND (z::int) = x AND (y AND z)" - by (simp add: bbw_assocs') - -lemma int_or_assoc: - "(x OR y) OR (z::int) = x OR (y OR z)" - by (simp add: bbw_assocs') - -lemma int_xor_assoc: - "(x XOR y) XOR (z::int) = x XOR (y XOR z)" - by (simp add: bbw_assocs') - -lemmas bbw_assocs = int_and_assoc int_or_assoc int_xor_assoc - -lemma bbw_lcs [simp]: - "(y::int) AND (x AND z) = x AND (y AND z)" - "(y::int) OR (x OR z) = x OR (y OR z)" - "(y::int) XOR (x XOR z) = x XOR (y XOR z)" - apply (auto simp: bbw_assocs [symmetric]) - apply (auto simp: bin_ops_comm) - done - -lemma bbw_not_dist: - "!!y::int. NOT (x OR y) = (NOT x) AND (NOT y)" - "!!y::int. NOT (x AND y) = (NOT x) OR (NOT y)" - apply (induct x rule: bin_induct) - apply auto - apply (case_tac [!] y rule: bin_exhaust) - apply (case_tac [!] bit, auto simp del: BIT_simps) - done - -lemma bbw_oa_dist: - "!!y z::int. (x AND y) OR z = - (x OR z) AND (y OR z)" - apply (induct x rule: bin_induct) - apply auto - apply (case_tac y rule: bin_exhaust) - apply (case_tac z rule: bin_exhaust) - apply (case_tac ba, auto simp del: BIT_simps) - done - -lemma bbw_ao_dist: - "!!y z::int. (x OR y) AND z = - (x AND z) OR (y AND z)" - apply (induct x rule: bin_induct) - apply auto - apply (case_tac y rule: bin_exhaust) - apply (case_tac z rule: bin_exhaust) - apply (case_tac ba, auto simp del: BIT_simps) - done - -(* -Why were these declared simp??? -declare bin_ops_comm [simp] bbw_assocs [simp] -*) - -lemma plus_and_or [rule_format]: - "ALL 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 split: bit.split) - done - -lemma le_int_or: - "!!x. bin_sign y = Int.Pls ==> x <= x OR y" - apply (induct y 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: less_eq_int_code) - done - -lemmas int_and_le = - xtr3 [OF bbw_ao_absorbs (2) [THEN conjunct2, symmetric] le_int_or] ; - -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)" - apply (induct n) - apply safe - apply (case_tac [!] x rule: bin_exhaust) - apply (simp_all del: BIT_simps) - apply (case_tac [!] y rule: bin_exhaust) - apply (simp_all del: BIT_simps) - apply (auto dest: not_B1_is_B0 intro: B1_ass_B0) - done - -(* interaction between bit-wise and arithmetic *) -(* good example of bin_induction *) -lemma bin_add_not: "x + NOT x = Int.Min" - apply (induct x rule: bin_induct) - apply clarsimp - apply clarsimp - apply (case_tac bit, auto) - done - -(* truncating results of bit-wise operations *) -lemma bin_trunc_ao: - "!!x y. (bintrunc n x) AND (bintrunc n y) = bintrunc n (x AND y)" - "!!x y. (bintrunc n x) OR (bintrunc n y) = bintrunc n (x OR y)" - apply (induct n) - apply auto - apply (case_tac [!] x rule: bin_exhaust) - apply (case_tac [!] y rule: bin_exhaust) - apply auto - done - -lemma bin_trunc_xor: - "!!x y. bintrunc n (bintrunc n x XOR bintrunc n y) = - bintrunc n (x XOR y)" - apply (induct n) - apply auto - apply (case_tac [!] x rule: bin_exhaust) - apply (case_tac [!] y rule: bin_exhaust) - apply auto - done - -lemma bin_trunc_not: - "!!x. bintrunc n (NOT (bintrunc n x)) = bintrunc n (NOT x)" - apply (induct n) - apply auto - apply (case_tac [!] x rule: bin_exhaust) - apply auto - done - -(* 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] - -subsection {* Setting and clearing bits *} - -primrec - bin_sc :: "nat => bit => 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" - -(** nth bit, set/clear **) - -lemma bin_nth_sc [simp]: - "!!w. bin_nth (bin_sc n b w) n = (b = 1)" - by (induct n) auto - -lemma bin_sc_sc_same [simp]: - "!!w. bin_sc n c (bin_sc n b w) = bin_sc n c w" - by (induct n) auto - -lemma bin_sc_sc_diff: - "!!w m. m ~= n ==> - bin_sc m c (bin_sc n b w) = bin_sc n b (bin_sc m c w)" - apply (induct n) - apply (case_tac [!] m) - apply auto - done - -lemma bin_nth_sc_gen: - "!!w m. bin_nth (bin_sc n b w) m = (if m = n then b = 1 else bin_nth w m)" - by (induct n) (case_tac [!] m, auto) - -lemma bin_sc_nth [simp]: - "!!w. (bin_sc n (If (bin_nth w n) 1 0) w) = w" - by (induct n) auto - -lemma bin_sign_sc [simp]: - "!!w. bin_sign (bin_sc n b w) = bin_sign w" - by (induct n) auto - -lemma bin_sc_bintr [simp]: - "!!w m. bintrunc m (bin_sc n x (bintrunc m (w))) = bintrunc m (bin_sc n x w)" - apply (induct n) - apply (case_tac [!] w rule: bin_exhaust) - apply (case_tac [!] m, auto) - done - -lemma bin_clr_le: - "!!w. bin_sc n 0 w <= w" - apply (induct n) - apply (case_tac [!] w rule: bin_exhaust) - apply (auto simp del: BIT_simps) - apply (unfold Bit_def) - apply (simp_all split: bit.split) - done - -lemma bin_set_ge: - "!!w. bin_sc n 1 w >= w" - apply (induct n) - apply (case_tac [!] w rule: bin_exhaust) - apply (auto simp del: BIT_simps) - apply (unfold Bit_def) - apply (simp_all split: bit.split) - done - -lemma bintr_bin_clr_le: - "!!w m. bintrunc n (bin_sc m 0 w) <= bintrunc n w" - apply (induct n) - apply simp - apply (case_tac w rule: bin_exhaust) - apply (case_tac m) - apply (auto simp del: BIT_simps) - apply (unfold Bit_def) - apply (simp_all split: bit.split) - done - -lemma bintr_bin_set_ge: - "!!w m. bintrunc n (bin_sc m 1 w) >= bintrunc n w" - apply (induct n) - apply simp - apply (case_tac w rule: bin_exhaust) - apply (case_tac m) - apply (auto simp del: BIT_simps) - apply (unfold Bit_def) - apply (simp_all split: bit.split) - done - -lemma bin_sc_FP [simp]: "bin_sc n 0 Int.Pls = Int.Pls" - by (induct n) auto - -lemma bin_sc_TM [simp]: "bin_sc n 1 Int.Min = Int.Min" - 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, standard] - -lemmas bin_sc_Suc_pred [simp] = - bin_sc_Suc_minus [of "number_of bin", simplified nobm1, standard] - - -subsection {* Splitting and concatenation *} - -definition bin_rcat :: "nat \ int list \ int" where - "bin_rcat n = foldl (%u v. bin_cat u n v) Int.Pls" - -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_sign_cat: - "!!y. bin_sign (bin_cat x n y) = bin_sign x" - by (induct n) 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_nth_cat: - "!!n y. 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) - apply clarsimp - apply (case_tac n, auto) - done - -lemma bin_nth_split: - "!!b c. bin_split n c = (a, b) ==> - (ALL k. bin_nth a k = bin_nth c (n + k)) & - (ALL k. bin_nth b k = (k < n & bin_nth c k))" - apply (induct n) - apply clarsimp - apply (clarsimp simp: Let_def split: ls_splits) - apply (case_tac k) - apply auto - done - -lemma bin_cat_assoc: - "!!z. bin_cat (bin_cat x m y) n z = bin_cat x (m + n) (bin_cat y n z)" - by (induct n) auto - -lemma bin_cat_assoc_sym: "!!z m. - bin_cat x m (bin_cat y n z) = bin_cat (bin_cat x (m - n) y) (min m n) z" - apply (induct n, clarsimp) - apply (case_tac m, auto) - done - -lemma bin_cat_Pls [simp]: - "!!w. bin_cat Int.Pls n w = bintrunc n w" - by (induct n) auto - -lemma bintr_cat1: - "!!b. bintrunc (k + n) (bin_cat a n b) = bin_cat (bintrunc k a) n b" - by (induct n) auto - -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]: - "!!b. bin_cat a n (bintrunc n b) = bin_cat a n b" - by (induct n) auto - -lemma split_bintrunc: - "!!b c. bin_split n c = (a, b) ==> b = bintrunc n c" - by (induct n) (auto simp: Let_def split: ls_splits) - -lemma bin_cat_split: - "!!v w. bin_split n w = (u, v) ==> w = bin_cat u n v" - by (induct n) (auto simp: Let_def split: ls_splits) - -lemma bin_split_cat: - "!!w. bin_split n (bin_cat v n w) = (v, bintrunc n w)" - by (induct n) auto - -lemma bin_split_Pls [simp]: - "bin_split n Int.Pls = (Int.Pls, Int.Pls)" - by (induct n) (auto simp: Let_def split: ls_splits) - -lemma bin_split_Min [simp]: - "bin_split n Int.Min = (Int.Min, bintrunc n Int.Min)" - by (induct n) (auto simp: Let_def split: ls_splits) - -lemma bin_split_trunc: - "!!m b c. bin_split (min m n) c = (a, b) ==> - bin_split n (bintrunc m c) = (bintrunc (m - n) a, b)" - apply (induct n, clarsimp) - apply (simp add: bin_rest_trunc Let_def split: ls_splits) - apply (case_tac m) - apply (auto simp: Let_def split: ls_splits) - done - -lemma bin_split_trunc1: - "!!m b c. bin_split n c = (a, b) ==> - bin_split n (bintrunc m c) = (bintrunc (m - n) a, bintrunc m b)" - apply (induct n, clarsimp) - apply (simp add: bin_rest_trunc Let_def split: ls_splits) - apply (case_tac m) - apply (auto simp: Let_def split: ls_splits) - done - -lemma bin_cat_num: - "!!b. bin_cat a n b = a * 2 ^ n + bintrunc n b" - apply (induct n, clarsimp) - apply (simp add: Bit_def cong: number_of_False_cong) - done - -lemma bin_split_num: - "!!b. bin_split n b = (b div 2 ^ n, b mod 2 ^ n)" - apply (induct n, clarsimp) - apply (simp add: bin_rest_div zdiv_zmult2_eq) - apply (case_tac b rule: bin_exhaust) - apply simp - apply (simp add: Bit_def mod_mult_mult1 p1mod22k - split: bit.split - cong: number_of_False_cong) - done - -subsection {* Miscellaneous lemmas *} - -lemma nth_2p_bin: - "!!m. bin_nth (2 ^ n) m = (m = n)" - apply (induct n) - apply clarsimp - apply safe - apply (case_tac m) - apply (auto simp: trans [OF numeral_1_eq_1 [symmetric] number_of_eq]) - apply (case_tac m) - apply (auto simp: Bit_B0_2t [symmetric]) - done - -(* for use when simplifying with bin_nth_Bit *) - -lemma ex_eq_or: - "(EX m. n = Suc m & (m = k | P m)) = (n = Suc k | (EX m. n = Suc m & P m))" - by auto - -end -