diff --git a/thys/Berlekamp_Zassenhaus/Finite_Field_Record_Based.thy b/thys/Berlekamp_Zassenhaus/Finite_Field_Record_Based.thy --- a/thys/Berlekamp_Zassenhaus/Finite_Field_Record_Based.thy +++ b/thys/Berlekamp_Zassenhaus/Finite_Field_Record_Based.thy @@ -1,1651 +1,1651 @@ (* Authors: Jose Divasón Sebastiaan Joosten René Thiemann Akihisa Yamada *) subsection \Finite Fields\ text \We provide four implementations for $GF(p)$ -- the field with $p$ elements for some prime $p$ -- one by int, one by integers, one by 32-bit numbers and one 64-bit implementation. Correctness of the implementations is proven by transfer rules to the type-based version of $GF(p)$.\ theory Finite_Field_Record_Based imports Finite_Field Arithmetic_Record_Based Native_Word.Uint32 Native_Word.Uint64 Native_Word.Code_Target_Bits_Int "HOL-Library.Code_Target_Numeral" begin (* mod on standard case which can immediately be mapped to target languages without considering special cases *) definition mod_nonneg_pos :: "integer \ integer \ integer" where "x \ 0 \ y > 0 \ mod_nonneg_pos x y = (x mod y)" code_printing \ \FIXME illusion of partiality\ constant mod_nonneg_pos \ (SML) "IntInf.mod/ ( _,/ _ )" and (Eval) "IntInf.mod/ ( _,/ _ )" and (OCaml) "Z.rem" and (Haskell) "Prelude.mod/ ( _ )/ ( _ )" and (Scala) "!((k: BigInt) => (l: BigInt) =>/ (k '% l))" definition mod_nonneg_pos_int :: "int \ int \ int" where "mod_nonneg_pos_int x y = int_of_integer (mod_nonneg_pos (integer_of_int x) (integer_of_int y))" lemma mod_nonneg_pos_int[simp]: "x \ 0 \ y > 0 \ mod_nonneg_pos_int x y = (x mod y)" unfolding mod_nonneg_pos_int_def using mod_nonneg_pos_def by simp context fixes p :: int begin definition plus_p :: "int \ int \ int" where "plus_p x y \ let z = x + y in if z \ p then z - p else z" definition minus_p :: "int \ int \ int" where "minus_p x y \ if y \ x then x - y else x + p - y" definition uminus_p :: "int \ int" where "uminus_p x = (if x = 0 then 0 else p - x)" definition mult_p :: "int \ int \ int" where "mult_p x y = (mod_nonneg_pos_int (x * y) p)" fun power_p :: "int \ nat \ int" where "power_p x n = (if n = 0 then 1 else let (d,r) = Divides.divmod_nat n 2; rec = power_p (mult_p x x) d in if r = 0 then rec else mult_p rec x)" text \In experiments with Berlekamp-factorization (where the prime $p$ is usually small), it turned out that taking the below implementation of inverse via exponentiation is faster than the one based on the extended Euclidean algorithm.\ definition inverse_p :: "int \ int" where "inverse_p x = (if x = 0 then 0 else power_p x (nat (p - 2)))" definition divide_p :: "int \ int \ int" where "divide_p x y = mult_p x (inverse_p y)" definition finite_field_ops_int :: "int arith_ops_record" where "finite_field_ops_int \ Arith_Ops_Record 0 1 plus_p mult_p minus_p uminus_p divide_p inverse_p (\ x y . if y = 0 then x else 0) (\ x . if x = 0 then 0 else 1) (\ x . x) (\ x . x) (\ x . x) (\ x. 0 \ x \ x < p)" end context fixes p :: uint32 begin definition plus_p32 :: "uint32 \ uint32 \ uint32" where "plus_p32 x y \ let z = x + y in if z \ p then z - p else z" definition minus_p32 :: "uint32 \ uint32 \ uint32" where "minus_p32 x y \ if y \ x then x - y else (x + p) - y" definition uminus_p32 :: "uint32 \ uint32" where "uminus_p32 x = (if x = 0 then 0 else p - x)" definition mult_p32 :: "uint32 \ uint32 \ uint32" where "mult_p32 x y = (x * y mod p)" lemma int_of_uint32_shift: "int_of_uint32 (drop_bit k n) = (int_of_uint32 n) div (2 ^ k)" apply transfer apply transfer apply (simp add: take_bit_drop_bit min_def) apply (simp add: drop_bit_eq_div) done lemma int_of_uint32_0_iff: "int_of_uint32 n = 0 \ n = 0" by (transfer, rule uint_0_iff) lemma int_of_uint32_0: "int_of_uint32 0 = 0" unfolding int_of_uint32_0_iff by simp lemma int_of_uint32_ge_0: "int_of_uint32 n \ 0" by (transfer, auto) lemma two_32: "2 ^ LENGTH(32) = (4294967296 :: int)" by simp lemma int_of_uint32_plus: "int_of_uint32 (x + y) = (int_of_uint32 x + int_of_uint32 y) mod 4294967296" by (transfer, unfold uint_word_ariths two_32, rule refl) lemma int_of_uint32_minus: "int_of_uint32 (x - y) = (int_of_uint32 x - int_of_uint32 y) mod 4294967296" by (transfer, unfold uint_word_ariths two_32, rule refl) lemma int_of_uint32_mult: "int_of_uint32 (x * y) = (int_of_uint32 x * int_of_uint32 y) mod 4294967296" by (transfer, unfold uint_word_ariths two_32, rule refl) lemma int_of_uint32_mod: "int_of_uint32 (x mod y) = (int_of_uint32 x mod int_of_uint32 y)" by (transfer, unfold uint_mod two_32, rule refl) lemma int_of_uint32_inv: "0 \ x \ x < 4294967296 \ int_of_uint32 (uint32_of_int x) = x" by transfer (simp add: take_bit_int_eq_self) function power_p32 :: "uint32 \ uint32 \ uint32" where "power_p32 x n = (if n = 0 then 1 else let rec = power_p32 (mult_p32 x x) (drop_bit 1 n) in if n AND 1 = 0 then rec else mult_p32 rec x)" by pat_completeness auto termination proof - { fix n :: uint32 assume "n \ 0" with int_of_uint32_ge_0[of n] int_of_uint32_0_iff[of n] have "int_of_uint32 n > 0" by auto hence "0 < int_of_uint32 n" "int_of_uint32 n div 2 < int_of_uint32 n" by auto } note * = this show ?thesis by (relation "measure (\ (x,n). nat (int_of_uint32 n))", auto simp: int_of_uint32_shift *) qed text \In experiments with Berlekamp-factorization (where the prime $p$ is usually small), it turned out that taking the below implementation of inverse via exponentiation is faster than the one based on the extended Euclidean algorithm.\ definition inverse_p32 :: "uint32 \ uint32" where "inverse_p32 x = (if x = 0 then 0 else power_p32 x (p - 2))" definition divide_p32 :: "uint32 \ uint32 \ uint32" where "divide_p32 x y = mult_p32 x (inverse_p32 y)" definition finite_field_ops32 :: "uint32 arith_ops_record" where "finite_field_ops32 \ Arith_Ops_Record 0 1 plus_p32 mult_p32 minus_p32 uminus_p32 divide_p32 inverse_p32 (\ x y . if y = 0 then x else 0) (\ x . if x = 0 then 0 else 1) (\ x . x) uint32_of_int int_of_uint32 (\ x. 0 \ x \ x < p)" end lemma shiftr_uint32_code [code_unfold]: "drop_bit 1 x = (uint32_shiftr x 1)" by (simp add: uint32_shiftr_def) (* ******************************************************************************** *) subsubsection \Transfer Relation\ locale mod_ring_locale = fixes p :: int and ty :: "'a :: nontriv itself" assumes p: "p = int CARD('a)" begin lemma nat_p: "nat p = CARD('a)" unfolding p by simp lemma p2: "p \ 2" unfolding p using nontriv[where 'a = 'a] by auto lemma p2_ident: "int (CARD('a) - 2) = p - 2" using p2 unfolding p by simp definition mod_ring_rel :: "int \ 'a mod_ring \ bool" where "mod_ring_rel x x' = (x = to_int_mod_ring x')" (* domain transfer rules *) lemma Domainp_mod_ring_rel [transfer_domain_rule]: "Domainp (mod_ring_rel) = (\ v. v \ {0 ..< p})" proof - { fix v :: int assume *: "0 \ v" "v < p" have "Domainp mod_ring_rel v" proof show "mod_ring_rel v (of_int_mod_ring v)" unfolding mod_ring_rel_def using * p by auto qed } note * = this show ?thesis by (intro ext iffI, insert range_to_int_mod_ring[where 'a = 'a] *, auto simp: mod_ring_rel_def p) qed (* left/right/bi-unique *) lemma bi_unique_mod_ring_rel [transfer_rule]: "bi_unique mod_ring_rel" "left_unique mod_ring_rel" "right_unique mod_ring_rel" unfolding mod_ring_rel_def bi_unique_def left_unique_def right_unique_def by auto (* left/right-total *) lemma right_total_mod_ring_rel [transfer_rule]: "right_total mod_ring_rel" unfolding mod_ring_rel_def right_total_def by simp (* ************************************************************************************ *) subsubsection \Transfer Rules\ (* 0 / 1 *) lemma mod_ring_0[transfer_rule]: "mod_ring_rel 0 0" unfolding mod_ring_rel_def by simp lemma mod_ring_1[transfer_rule]: "mod_ring_rel 1 1" unfolding mod_ring_rel_def by simp (* addition *) lemma plus_p_mod_def: assumes x: "x \ {0 ..< p}" and y: "y \ {0 ..< p}" shows "plus_p p x y = ((x + y) mod p)" proof (cases "p \ x + y") case False thus ?thesis using x y unfolding plus_p_def Let_def by auto next case True from True x y have *: "p > 0" "0 \ x + y - p" "x + y - p < p" by auto from True have id: "plus_p p x y = x + y - p" unfolding plus_p_def by auto show ?thesis unfolding id using * using mod_pos_pos_trivial by fastforce qed lemma mod_ring_plus[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> mod_ring_rel) (plus_p p) (+)" proof - { fix x y :: "'a mod_ring" have "plus_p p (to_int_mod_ring x) (to_int_mod_ring y) = to_int_mod_ring (x + y)" by (transfer, subst plus_p_mod_def, auto, auto simp: p) } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *) qed (* subtraction *) lemma minus_p_mod_def: assumes x: "x \ {0 ..< p}" and y: "y \ {0 ..< p}" shows "minus_p p x y = ((x - y) mod p)" proof (cases "x - y < 0") case False thus ?thesis using x y unfolding minus_p_def Let_def by auto next case True from True x y have *: "p > 0" "0 \ x - y + p" "x - y + p < p" by auto from True have id: "minus_p p x y = x - y + p" unfolding minus_p_def by auto show ?thesis unfolding id using * using mod_pos_pos_trivial by fastforce qed lemma mod_ring_minus[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> mod_ring_rel) (minus_p p) (-)" proof - { fix x y :: "'a mod_ring" have "minus_p p (to_int_mod_ring x) (to_int_mod_ring y) = to_int_mod_ring (x - y)" by (transfer, subst minus_p_mod_def, auto simp: p) } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *) qed (* unary minus *) lemma mod_ring_uminus[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel) (uminus_p p) uminus" proof - { fix x :: "'a mod_ring" have "uminus_p p (to_int_mod_ring x) = to_int_mod_ring (uminus x)" by (transfer, auto simp: uminus_p_def p) } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *) qed (* multiplication *) lemma mod_ring_mult[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> mod_ring_rel) (mult_p p) ((*))" proof - { fix x y :: "'a mod_ring" have "mult_p p (to_int_mod_ring x) (to_int_mod_ring y) = to_int_mod_ring (x * y)" by (transfer, auto simp: mult_p_def p) } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *) qed (* equality *) lemma mod_ring_eq[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> (=)) (=) (=)" by (intro rel_funI, auto simp: mod_ring_rel_def) (* power *) lemma mod_ring_power[transfer_rule]: "(mod_ring_rel ===> (=) ===> mod_ring_rel) (power_p p) (^)" proof (intro rel_funI, clarify, unfold binary_power[symmetric], goal_cases) fix x y n assume xy: "mod_ring_rel x y" from xy show "mod_ring_rel (power_p p x n) (binary_power y n)" proof (induct y n arbitrary: x rule: binary_power.induct) case (1 x n y) note 1(2)[transfer_rule] show ?case proof (cases "n = 0") case True thus ?thesis by (simp add: mod_ring_1) next case False obtain d r where id: "Divides.divmod_nat n 2 = (d,r)" by force let ?int = "power_p p (mult_p p y y) d" let ?gfp = "binary_power (x * x) d" from False have id': "?thesis = (mod_ring_rel (if r = 0 then ?int else mult_p p ?int y) (if r = 0 then ?gfp else ?gfp * x))" unfolding power_p.simps[of _ _ n] binary_power.simps[of _ n] Let_def id split by simp have [transfer_rule]: "mod_ring_rel ?int ?gfp" by (rule 1(1)[OF False refl id[symmetric]], transfer_prover) show ?thesis unfolding id' by transfer_prover qed qed qed declare power_p.simps[simp del] lemma ring_finite_field_ops_int: "ring_ops (finite_field_ops_int p) mod_ring_rel" by (unfold_locales, auto simp: finite_field_ops_int_def bi_unique_mod_ring_rel right_total_mod_ring_rel mod_ring_plus mod_ring_minus mod_ring_uminus mod_ring_mult mod_ring_eq mod_ring_0 mod_ring_1 Domainp_mod_ring_rel) end locale prime_field = mod_ring_locale p ty for p and ty :: "'a :: prime_card itself" begin lemma prime: "prime p" unfolding p using prime_card[where 'a = 'a] by simp (* mod *) lemma mod_ring_mod[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> mod_ring_rel) ((\ x y. if y = 0 then x else 0)) (mod)" proof - { fix x y :: "'a mod_ring" have "(if to_int_mod_ring y = 0 then to_int_mod_ring x else 0) = to_int_mod_ring (x mod y)" unfolding modulo_mod_ring_def by auto } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *[symmetric]) qed (* normalize *) lemma mod_ring_normalize[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel) ((\ x. if x = 0 then 0 else 1)) normalize" proof - { fix x :: "'a mod_ring" have "(if to_int_mod_ring x = 0 then 0 else 1) = to_int_mod_ring (normalize x)" unfolding normalize_mod_ring_def by auto } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *[symmetric]) qed (* unit_factor *) lemma mod_ring_unit_factor[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel) (\ x. x) unit_factor" proof - { fix x :: "'a mod_ring" have "to_int_mod_ring x = to_int_mod_ring (unit_factor x)" unfolding unit_factor_mod_ring_def by auto } note * = this show ?thesis by (intro rel_funI, auto simp: mod_ring_rel_def *[symmetric]) qed (* inverse *) lemma mod_ring_inverse[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel) (inverse_p p) inverse" proof (intro rel_funI) fix x y assume [transfer_rule]: "mod_ring_rel x y" show "mod_ring_rel (inverse_p p x) (inverse y)" unfolding inverse_p_def inverse_mod_ring_def apply (transfer_prover_start) apply (transfer_step)+ apply (unfold p2_ident) apply (rule refl) done qed (* division *) lemma mod_ring_divide[transfer_rule]: "(mod_ring_rel ===> mod_ring_rel ===> mod_ring_rel) (divide_p p) (/)" unfolding divide_p_def[abs_def] divide_mod_ring_def[abs_def] inverse_mod_ring_def[symmetric] by transfer_prover lemma mod_ring_rel_unsafe: assumes "x < CARD('a)" shows "mod_ring_rel (int x) (of_nat x)" "0 < x \ of_nat x \ (0 :: 'a mod_ring)" proof - have id: "of_nat x = (of_int (int x) :: 'a mod_ring)" by simp show "mod_ring_rel (int x) (of_nat x)" "0 < x \ of_nat x \ (0 :: 'a mod_ring)" unfolding id unfolding mod_ring_rel_def proof (auto simp add: assms of_int_of_int_mod_ring) assume "0 < x" with assms have "of_int_mod_ring (int x) \ (0 :: 'a mod_ring)" by (metis (no_types) less_imp_of_nat_less less_irrefl of_nat_0_le_iff of_nat_0_less_iff to_int_mod_ring_hom.hom_zero to_int_mod_ring_of_int_mod_ring) thus "of_int_mod_ring (int x) = (0 :: 'a mod_ring) \ False" by blast qed qed lemma finite_field_ops_int: "field_ops (finite_field_ops_int p) mod_ring_rel" by (unfold_locales, auto simp: finite_field_ops_int_def bi_unique_mod_ring_rel right_total_mod_ring_rel mod_ring_divide mod_ring_plus mod_ring_minus mod_ring_uminus mod_ring_inverse mod_ring_mod mod_ring_unit_factor mod_ring_normalize mod_ring_mult mod_ring_eq mod_ring_0 mod_ring_1 Domainp_mod_ring_rel) end text \Once we have proven the soundness of the implementation, we do not care any longer that @{typ "'a mod_ring"} has been defined internally via lifting. Disabling the transfer-rules will hide the internal definition in further applications of transfer.\ lifting_forget mod_ring.lifting text \For soundness of the 32-bit implementation, we mainly prove that this implementation implements the int-based implementation of the mod-ring.\ context mod_ring_locale begin context fixes pp :: "uint32" assumes ppp: "p = int_of_uint32 pp" and small: "p \ 65535" begin lemmas uint32_simps = int_of_uint32_0 int_of_uint32_plus int_of_uint32_minus int_of_uint32_mult definition urel32 :: "uint32 \ int \ bool" where "urel32 x y = (y = int_of_uint32 x \ y < p)" definition mod_ring_rel32 :: "uint32 \ 'a mod_ring \ bool" where "mod_ring_rel32 x y = (\ z. urel32 x z \ mod_ring_rel z y)" lemma urel32_0: "urel32 0 0" unfolding urel32_def using p2 by (simp, transfer, simp) lemma urel32_1: "urel32 1 1" unfolding urel32_def using p2 by (simp, transfer, simp) lemma le_int_of_uint32: "(x \ y) = (int_of_uint32 x \ int_of_uint32 y)" by (transfer, simp add: word_le_def) lemma urel32_plus: assumes "urel32 x y" "urel32 x' y'" shows "urel32 (plus_p32 pp x x') (plus_p p y y')" proof - let ?x = "int_of_uint32 x" let ?x' = "int_of_uint32 x'" let ?p = "int_of_uint32 pp" from assms int_of_uint32_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel32_def by auto have le: "(pp \ x + x') = (?p \ ?x + ?x')" unfolding le_int_of_uint32 using rel small by (auto simp: uint32_simps) show ?thesis proof (cases "?p \ ?x + ?x'") case True hence True: "(?p \ ?x + ?x') = True" by simp show ?thesis unfolding id using small rel unfolding plus_p32_def plus_p_def Let_def urel32_def unfolding ppp le True if_True using True by (auto simp: uint32_simps) next case False hence False: "(?p \ ?x + ?x') = False" by simp show ?thesis unfolding id using small rel unfolding plus_p32_def plus_p_def Let_def urel32_def unfolding ppp le False if_False using False by (auto simp: uint32_simps) qed qed lemma urel32_minus: assumes "urel32 x y" "urel32 x' y'" shows "urel32 (minus_p32 pp x x') (minus_p p y y')" proof - let ?x = "int_of_uint32 x" let ?x' = "int_of_uint32 x'" from assms int_of_uint32_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel32_def by auto have le: "(x' \ x) = (?x' \ ?x)" unfolding le_int_of_uint32 using rel small by (auto simp: uint32_simps) show ?thesis proof (cases "?x' \ ?x") case True hence True: "(?x' \ ?x) = True" by simp show ?thesis unfolding id using small rel unfolding minus_p32_def minus_p_def Let_def urel32_def unfolding ppp le True if_True using True by (auto simp: uint32_simps) next case False hence False: "(?x' \ ?x) = False" by simp show ?thesis unfolding id using small rel unfolding minus_p32_def minus_p_def Let_def urel32_def unfolding ppp le False if_False using False by (auto simp: uint32_simps) qed qed lemma urel32_uminus: assumes "urel32 x y" shows "urel32 (uminus_p32 pp x) (uminus_p p y)" proof - let ?x = "int_of_uint32 x" from assms int_of_uint32_ge_0 have id: "y = ?x" and rel: "0 \ ?x" "?x < p" unfolding urel32_def by auto have le: "(x = 0) = (?x = 0)" unfolding int_of_uint32_0_iff using rel small by (auto simp: uint32_simps) show ?thesis proof (cases "?x = 0") case True hence True: "(?x = 0) = True" by simp show ?thesis unfolding id using small rel unfolding uminus_p32_def uminus_p_def Let_def urel32_def unfolding ppp le True if_True using True by (auto simp: uint32_simps) next case False hence False: "(?x = 0) = False" by simp show ?thesis unfolding id using small rel unfolding uminus_p32_def uminus_p_def Let_def urel32_def unfolding ppp le False if_False using False by (auto simp: uint32_simps) qed qed lemma urel32_mult: assumes "urel32 x y" "urel32 x' y'" shows "urel32 (mult_p32 pp x x') (mult_p p y y')" proof - let ?x = "int_of_uint32 x" let ?x' = "int_of_uint32 x'" from assms int_of_uint32_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' < p" unfolding urel32_def by auto from rel have "?x * ?x' < p * p" by (metis mult_strict_mono') also have "\ \ 65536 * 65536" by (rule mult_mono, insert p2 small, auto) finally have le: "?x * ?x' < 4294967296" by simp show ?thesis unfolding id using small rel unfolding mult_p32_def mult_p_def Let_def urel32_def unfolding ppp by (auto simp: uint32_simps, unfold int_of_uint32_mod int_of_uint32_mult, subst mod_pos_pos_trivial[of _ 4294967296], insert le, auto) qed lemma urel32_eq: assumes "urel32 x y" "urel32 x' y'" shows "(x = x') = (y = y')" proof - let ?x = "int_of_uint32 x" let ?x' = "int_of_uint32 x'" from assms int_of_uint32_ge_0 have id: "y = ?x" "y' = ?x'" unfolding urel32_def by auto show ?thesis unfolding id by (transfer, transfer) rule qed lemma urel32_normalize: assumes x: "urel32 x y" shows "urel32 (if x = 0 then 0 else 1) (if y = 0 then 0 else 1)" unfolding urel32_eq[OF x urel32_0] using urel32_0 urel32_1 by auto lemma urel32_mod: assumes x: "urel32 x x'" and y: "urel32 y y'" shows "urel32 (if y = 0 then x else 0) (if y' = 0 then x' else 0)" unfolding urel32_eq[OF y urel32_0] using urel32_0 x by auto lemma urel32_power: "urel32 x x' \ urel32 y (int y') \ urel32 (power_p32 pp x y) (power_p p x' y')" proof (induct x' y' arbitrary: x y rule: power_p.induct[of _ p]) case (1 x' y' x y) note x = 1(2) note y = 1(3) show ?case proof (cases "y' = 0") case True hence y: "y = 0" using urel32_eq[OF y urel32_0] by auto show ?thesis unfolding y True by (simp add: power_p.simps urel32_1) next case False hence id: "(y = 0) = False" "(y' = 0) = False" using urel32_eq[OF y urel32_0] by auto obtain d' r' where dr': "Divides.divmod_nat y' 2 = (d',r')" by force from divmod_nat_def[of y' 2, unfolded dr'] have r': "r' = y' mod 2" and d': "d' = y' div 2" by auto have "urel32 (y AND 1) r'" unfolding r' using y unfolding urel32_def using small apply (simp add: ppp and_one_eq) apply transfer apply transfer apply (auto simp add: zmod_int take_bit_int_eq_self) apply (rule le_less_trans) apply (rule zmod_le_nonneg_dividend) apply simp_all done from urel32_eq[OF this urel32_0] have rem: "(y AND 1 = 0) = (r' = 0)" by simp have div: "urel32 (drop_bit 1 y) (int d')" unfolding d' using y unfolding urel32_def using small unfolding ppp apply transfer apply transfer - apply (auto simp add: drop_bit_Suc) + apply (auto simp add: drop_bit_Suc take_bit_int_eq_self) done note IH = 1(1)[OF False refl dr'[symmetric] urel32_mult[OF x x] div] show ?thesis unfolding power_p.simps[of _ _ "y'"] power_p32.simps[of _ _ y] dr' id if_False rem using IH urel32_mult[OF IH x] by (auto simp: Let_def) qed qed lemma urel32_inverse: assumes x: "urel32 x x'" shows "urel32 (inverse_p32 pp x) (inverse_p p x')" proof - have p: "urel32 (pp - 2) (int (nat (p - 2)))" using p2 small unfolding urel32_def unfolding ppp by (transfer, auto simp: uint_word_ariths) show ?thesis unfolding inverse_p32_def inverse_p_def urel32_eq[OF x urel32_0] using urel32_0 urel32_power[OF x p] by auto qed lemma mod_ring_0_32: "mod_ring_rel32 0 0" using urel32_0 mod_ring_0 unfolding mod_ring_rel32_def by blast lemma mod_ring_1_32: "mod_ring_rel32 1 1" using urel32_1 mod_ring_1 unfolding mod_ring_rel32_def by blast lemma mod_ring_uminus32: "(mod_ring_rel32 ===> mod_ring_rel32) (uminus_p32 pp) uminus" using urel32_uminus mod_ring_uminus unfolding mod_ring_rel32_def rel_fun_def by blast lemma mod_ring_plus32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> mod_ring_rel32) (plus_p32 pp) (+)" using urel32_plus mod_ring_plus unfolding mod_ring_rel32_def rel_fun_def by blast lemma mod_ring_minus32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> mod_ring_rel32) (minus_p32 pp) (-)" using urel32_minus mod_ring_minus unfolding mod_ring_rel32_def rel_fun_def by blast lemma mod_ring_mult32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> mod_ring_rel32) (mult_p32 pp) ((*))" using urel32_mult mod_ring_mult unfolding mod_ring_rel32_def rel_fun_def by blast lemma mod_ring_eq32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> (=)) (=) (=)" using urel32_eq mod_ring_eq unfolding mod_ring_rel32_def rel_fun_def by blast lemma urel32_inj: "urel32 x y \ urel32 x z \ y = z" using urel32_eq[of x y x z] by auto lemma urel32_inj': "urel32 x z \ urel32 y z \ x = y" using urel32_eq[of x z y z] by auto lemma bi_unique_mod_ring_rel32: "bi_unique mod_ring_rel32" "left_unique mod_ring_rel32" "right_unique mod_ring_rel32" using bi_unique_mod_ring_rel urel32_inj' unfolding mod_ring_rel32_def bi_unique_def left_unique_def right_unique_def by (auto simp: urel32_def) lemma right_total_mod_ring_rel32: "right_total mod_ring_rel32" unfolding mod_ring_rel32_def right_total_def proof fix y :: "'a mod_ring" from right_total_mod_ring_rel[unfolded right_total_def, rule_format, of y] obtain z where zy: "mod_ring_rel z y" by auto hence zp: "0 \ z" "z < p" unfolding mod_ring_rel_def p using range_to_int_mod_ring[where 'a = 'a] by auto hence "urel32 (uint32_of_int z) z" unfolding urel32_def using small unfolding ppp by (auto simp: int_of_uint32_inv) with zy show "\ x z. urel32 x z \ mod_ring_rel z y" by blast qed lemma Domainp_mod_ring_rel32: "Domainp mod_ring_rel32 = (\x. 0 \ x \ x < pp)" proof fix x show "Domainp mod_ring_rel32 x = (0 \ x \ x < pp)" unfolding Domainp.simps unfolding mod_ring_rel32_def proof let ?i = "int_of_uint32" assume *: "0 \ x \ x < pp" hence "0 \ ?i x \ ?i x < p" using small unfolding ppp by (transfer, auto simp: word_less_def) hence "?i x \ {0 ..< p}" by auto with Domainp_mod_ring_rel have "Domainp mod_ring_rel (?i x)" by auto from this[unfolded Domainp.simps] obtain b where b: "mod_ring_rel (?i x) b" by auto show "\a b. x = a \ (\z. urel32 a z \ mod_ring_rel z b)" proof (intro exI, rule conjI[OF refl], rule exI, rule conjI[OF _ b]) show "urel32 x (?i x)" unfolding urel32_def using small * unfolding ppp by (transfer, auto simp: word_less_def) qed next assume "\a b. x = a \ (\z. urel32 a z \ mod_ring_rel z b)" then obtain b z where xz: "urel32 x z" and zb: "mod_ring_rel z b" by auto hence "Domainp mod_ring_rel z" by auto with Domainp_mod_ring_rel have "0 \ z" "z < p" by auto with xz show "0 \ x \ x < pp" unfolding urel32_def using small unfolding ppp by (transfer, auto simp: word_less_def) qed qed lemma ring_finite_field_ops32: "ring_ops (finite_field_ops32 pp) mod_ring_rel32" by (unfold_locales, auto simp: finite_field_ops32_def bi_unique_mod_ring_rel32 right_total_mod_ring_rel32 mod_ring_plus32 mod_ring_minus32 mod_ring_uminus32 mod_ring_mult32 mod_ring_eq32 mod_ring_0_32 mod_ring_1_32 Domainp_mod_ring_rel32) end end context prime_field begin context fixes pp :: "uint32" assumes *: "p = int_of_uint32 pp" "p \ 65535" begin lemma mod_ring_normalize32: "(mod_ring_rel32 ===> mod_ring_rel32) (\x. if x = 0 then 0 else 1) normalize" using urel32_normalize[OF *] mod_ring_normalize unfolding mod_ring_rel32_def[OF *] rel_fun_def by blast lemma mod_ring_mod32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> mod_ring_rel32) (\x y. if y = 0 then x else 0) (mod)" using urel32_mod[OF *] mod_ring_mod unfolding mod_ring_rel32_def[OF *] rel_fun_def by blast lemma mod_ring_unit_factor32: "(mod_ring_rel32 ===> mod_ring_rel32) (\x. x) unit_factor" using mod_ring_unit_factor unfolding mod_ring_rel32_def[OF *] rel_fun_def by blast lemma mod_ring_inverse32: "(mod_ring_rel32 ===> mod_ring_rel32) (inverse_p32 pp) inverse" using urel32_inverse[OF *] mod_ring_inverse unfolding mod_ring_rel32_def[OF *] rel_fun_def by blast lemma mod_ring_divide32: "(mod_ring_rel32 ===> mod_ring_rel32 ===> mod_ring_rel32) (divide_p32 pp) (/)" using mod_ring_inverse32 mod_ring_mult32[OF *] unfolding divide_p32_def divide_mod_ring_def inverse_mod_ring_def[symmetric] rel_fun_def by blast lemma finite_field_ops32: "field_ops (finite_field_ops32 pp) mod_ring_rel32" by (unfold_locales, insert ring_finite_field_ops32[OF *], auto simp: ring_ops_def finite_field_ops32_def mod_ring_divide32 mod_ring_inverse32 mod_ring_mod32 mod_ring_normalize32) end end (* now there is 64-bit time *) context fixes p :: uint64 begin definition plus_p64 :: "uint64 \ uint64 \ uint64" where "plus_p64 x y \ let z = x + y in if z \ p then z - p else z" definition minus_p64 :: "uint64 \ uint64 \ uint64" where "minus_p64 x y \ if y \ x then x - y else (x + p) - y" definition uminus_p64 :: "uint64 \ uint64" where "uminus_p64 x = (if x = 0 then 0 else p - x)" definition mult_p64 :: "uint64 \ uint64 \ uint64" where "mult_p64 x y = (x * y mod p)" lemma int_of_uint64_shift: "int_of_uint64 (drop_bit k n) = (int_of_uint64 n) div (2 ^ k)" apply transfer apply transfer apply (simp add: take_bit_drop_bit min_def) apply (simp add: drop_bit_eq_div) done lemma int_of_uint64_0_iff: "int_of_uint64 n = 0 \ n = 0" by (transfer, rule uint_0_iff) lemma int_of_uint64_0: "int_of_uint64 0 = 0" unfolding int_of_uint64_0_iff by simp lemma int_of_uint64_ge_0: "int_of_uint64 n \ 0" by (transfer, auto) lemma two_64: "2 ^ LENGTH(64) = (18446744073709551616 :: int)" by simp lemma int_of_uint64_plus: "int_of_uint64 (x + y) = (int_of_uint64 x + int_of_uint64 y) mod 18446744073709551616" by (transfer, unfold uint_word_ariths two_64, rule refl) lemma int_of_uint64_minus: "int_of_uint64 (x - y) = (int_of_uint64 x - int_of_uint64 y) mod 18446744073709551616" by (transfer, unfold uint_word_ariths two_64, rule refl) lemma int_of_uint64_mult: "int_of_uint64 (x * y) = (int_of_uint64 x * int_of_uint64 y) mod 18446744073709551616" by (transfer, unfold uint_word_ariths two_64, rule refl) lemma int_of_uint64_mod: "int_of_uint64 (x mod y) = (int_of_uint64 x mod int_of_uint64 y)" by (transfer, unfold uint_mod two_64, rule refl) lemma int_of_uint64_inv: "0 \ x \ x < 18446744073709551616 \ int_of_uint64 (uint64_of_int x) = x" by transfer (simp add: take_bit_int_eq_self) function power_p64 :: "uint64 \ uint64 \ uint64" where "power_p64 x n = (if n = 0 then 1 else let rec = power_p64 (mult_p64 x x) (drop_bit 1 n) in if n AND 1 = 0 then rec else mult_p64 rec x)" by pat_completeness auto termination proof - { fix n :: uint64 assume "n \ 0" with int_of_uint64_ge_0[of n] int_of_uint64_0_iff[of n] have "int_of_uint64 n > 0" by auto hence "0 < int_of_uint64 n" "int_of_uint64 n div 2 < int_of_uint64 n" by auto } note * = this show ?thesis by (relation "measure (\ (x,n). nat (int_of_uint64 n))", auto simp: int_of_uint64_shift *) qed text \In experiments with Berlekamp-factorization (where the prime $p$ is usually small), it turned out that taking the below implementation of inverse via exponentiation is faster than the one based on the extended Euclidean algorithm.\ definition inverse_p64 :: "uint64 \ uint64" where "inverse_p64 x = (if x = 0 then 0 else power_p64 x (p - 2))" definition divide_p64 :: "uint64 \ uint64 \ uint64" where "divide_p64 x y = mult_p64 x (inverse_p64 y)" definition finite_field_ops64 :: "uint64 arith_ops_record" where "finite_field_ops64 \ Arith_Ops_Record 0 1 plus_p64 mult_p64 minus_p64 uminus_p64 divide_p64 inverse_p64 (\ x y . if y = 0 then x else 0) (\ x . if x = 0 then 0 else 1) (\ x . x) uint64_of_int int_of_uint64 (\ x. 0 \ x \ x < p)" end lemma shiftr_uint64_code [code_unfold]: "drop_bit 1 x = (uint64_shiftr x 1)" by (simp add: uint64_shiftr_def) text \For soundness of the 64-bit implementation, we mainly prove that this implementation implements the int-based implementation of GF(p).\ context mod_ring_locale begin context fixes pp :: "uint64" assumes ppp: "p = int_of_uint64 pp" and small: "p \ 4294967295" begin lemmas uint64_simps = int_of_uint64_0 int_of_uint64_plus int_of_uint64_minus int_of_uint64_mult definition urel64 :: "uint64 \ int \ bool" where "urel64 x y = (y = int_of_uint64 x \ y < p)" definition mod_ring_rel64 :: "uint64 \ 'a mod_ring \ bool" where "mod_ring_rel64 x y = (\ z. urel64 x z \ mod_ring_rel z y)" lemma urel64_0: "urel64 0 0" unfolding urel64_def using p2 by (simp, transfer, simp) lemma urel64_1: "urel64 1 1" unfolding urel64_def using p2 by (simp, transfer, simp) lemma le_int_of_uint64: "(x \ y) = (int_of_uint64 x \ int_of_uint64 y)" by (transfer, simp add: word_le_def) lemma urel64_plus: assumes "urel64 x y" "urel64 x' y'" shows "urel64 (plus_p64 pp x x') (plus_p p y y')" proof - let ?x = "int_of_uint64 x" let ?x' = "int_of_uint64 x'" let ?p = "int_of_uint64 pp" from assms int_of_uint64_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel64_def by auto have le: "(pp \ x + x') = (?p \ ?x + ?x')" unfolding le_int_of_uint64 using rel small by (auto simp: uint64_simps) show ?thesis proof (cases "?p \ ?x + ?x'") case True hence True: "(?p \ ?x + ?x') = True" by simp show ?thesis unfolding id using small rel unfolding plus_p64_def plus_p_def Let_def urel64_def unfolding ppp le True if_True using True by (auto simp: uint64_simps) next case False hence False: "(?p \ ?x + ?x') = False" by simp show ?thesis unfolding id using small rel unfolding plus_p64_def plus_p_def Let_def urel64_def unfolding ppp le False if_False using False by (auto simp: uint64_simps) qed qed lemma urel64_minus: assumes "urel64 x y" "urel64 x' y'" shows "urel64 (minus_p64 pp x x') (minus_p p y y')" proof - let ?x = "int_of_uint64 x" let ?x' = "int_of_uint64 x'" from assms int_of_uint64_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel64_def by auto have le: "(x' \ x) = (?x' \ ?x)" unfolding le_int_of_uint64 using rel small by (auto simp: uint64_simps) show ?thesis proof (cases "?x' \ ?x") case True hence True: "(?x' \ ?x) = True" by simp show ?thesis unfolding id using small rel unfolding minus_p64_def minus_p_def Let_def urel64_def unfolding ppp le True if_True using True by (auto simp: uint64_simps) next case False hence False: "(?x' \ ?x) = False" by simp show ?thesis unfolding id using small rel unfolding minus_p64_def minus_p_def Let_def urel64_def unfolding ppp le False if_False using False by (auto simp: uint64_simps) qed qed lemma urel64_uminus: assumes "urel64 x y" shows "urel64 (uminus_p64 pp x) (uminus_p p y)" proof - let ?x = "int_of_uint64 x" from assms int_of_uint64_ge_0 have id: "y = ?x" and rel: "0 \ ?x" "?x < p" unfolding urel64_def by auto have le: "(x = 0) = (?x = 0)" unfolding int_of_uint64_0_iff using rel small by (auto simp: uint64_simps) show ?thesis proof (cases "?x = 0") case True hence True: "(?x = 0) = True" by simp show ?thesis unfolding id using small rel unfolding uminus_p64_def uminus_p_def Let_def urel64_def unfolding ppp le True if_True using True by (auto simp: uint64_simps) next case False hence False: "(?x = 0) = False" by simp show ?thesis unfolding id using small rel unfolding uminus_p64_def uminus_p_def Let_def urel64_def unfolding ppp le False if_False using False by (auto simp: uint64_simps) qed qed lemma urel64_mult: assumes "urel64 x y" "urel64 x' y'" shows "urel64 (mult_p64 pp x x') (mult_p p y y')" proof - let ?x = "int_of_uint64 x" let ?x' = "int_of_uint64 x'" from assms int_of_uint64_ge_0 have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' < p" unfolding urel64_def by auto from rel have "?x * ?x' < p * p" by (metis mult_strict_mono') also have "\ \ 4294967296 * 4294967296" by (rule mult_mono, insert p2 small, auto) finally have le: "?x * ?x' < 18446744073709551616" by simp show ?thesis unfolding id using small rel unfolding mult_p64_def mult_p_def Let_def urel64_def unfolding ppp by (auto simp: uint64_simps, unfold int_of_uint64_mod int_of_uint64_mult, subst mod_pos_pos_trivial[of _ 18446744073709551616], insert le, auto) qed lemma urel64_eq: assumes "urel64 x y" "urel64 x' y'" shows "(x = x') = (y = y')" proof - let ?x = "int_of_uint64 x" let ?x' = "int_of_uint64 x'" from assms int_of_uint64_ge_0 have id: "y = ?x" "y' = ?x'" unfolding urel64_def by auto show ?thesis unfolding id by (transfer, transfer) rule qed lemma urel64_normalize: assumes x: "urel64 x y" shows "urel64 (if x = 0 then 0 else 1) (if y = 0 then 0 else 1)" unfolding urel64_eq[OF x urel64_0] using urel64_0 urel64_1 by auto lemma urel64_mod: assumes x: "urel64 x x'" and y: "urel64 y y'" shows "urel64 (if y = 0 then x else 0) (if y' = 0 then x' else 0)" unfolding urel64_eq[OF y urel64_0] using urel64_0 x by auto lemma urel64_power: "urel64 x x' \ urel64 y (int y') \ urel64 (power_p64 pp x y) (power_p p x' y')" proof (induct x' y' arbitrary: x y rule: power_p.induct[of _ p]) case (1 x' y' x y) note x = 1(2) note y = 1(3) show ?case proof (cases "y' = 0") case True hence y: "y = 0" using urel64_eq[OF y urel64_0] by auto show ?thesis unfolding y True by (simp add: power_p.simps urel64_1) next case False hence id: "(y = 0) = False" "(y' = 0) = False" using urel64_eq[OF y urel64_0] by auto obtain d' r' where dr': "Divides.divmod_nat y' 2 = (d',r')" by force from divmod_nat_def[of y' 2, unfolded dr'] have r': "r' = y' mod 2" and d': "d' = y' div 2" by auto have "urel64 (y AND 1) r'" unfolding r' using y unfolding urel64_def using small apply (simp add: ppp and_one_eq) apply transfer apply transfer apply (auto simp add: int_eq_iff nat_take_bit_eq nat_mod_distrib zmod_int) apply (auto simp add: zmod_int mod_2_eq_odd) apply (auto simp add: less_le) apply (auto simp add: le_less) apply (metis linorder_neqE_linordered_idom mod_pos_pos_trivial not_take_bit_negative power_0 take_bit_0 take_bit_eq_mod take_bit_nonnegative) apply (metis even_take_bit_eq mod_pos_pos_trivial neq0_conv numeral_eq_Suc power_0 take_bit_eq_mod take_bit_nonnegative zero_less_Suc) done from urel64_eq[OF this urel64_0] have rem: "(y AND 1 = 0) = (r' = 0)" by simp have div: "urel64 (drop_bit 1 y) (int d')" unfolding d' using y unfolding urel64_def using small unfolding ppp apply transfer apply transfer - apply (auto simp add: drop_bit_Suc) + apply (auto simp add: drop_bit_Suc take_bit_int_eq_self) done note IH = 1(1)[OF False refl dr'[symmetric] urel64_mult[OF x x] div] show ?thesis unfolding power_p.simps[of _ _ "y'"] power_p64.simps[of _ _ y] dr' id if_False rem using IH urel64_mult[OF IH x] by (auto simp: Let_def) qed qed lemma urel64_inverse: assumes x: "urel64 x x'" shows "urel64 (inverse_p64 pp x) (inverse_p p x')" proof - have p: "urel64 (pp - 2) (int (nat (p - 2)))" using p2 small unfolding urel64_def unfolding ppp by (transfer, auto simp: uint_word_ariths) show ?thesis unfolding inverse_p64_def inverse_p_def urel64_eq[OF x urel64_0] using urel64_0 urel64_power[OF x p] by auto qed lemma mod_ring_0_64: "mod_ring_rel64 0 0" using urel64_0 mod_ring_0 unfolding mod_ring_rel64_def by blast lemma mod_ring_1_64: "mod_ring_rel64 1 1" using urel64_1 mod_ring_1 unfolding mod_ring_rel64_def by blast lemma mod_ring_uminus64: "(mod_ring_rel64 ===> mod_ring_rel64) (uminus_p64 pp) uminus" using urel64_uminus mod_ring_uminus unfolding mod_ring_rel64_def rel_fun_def by blast lemma mod_ring_plus64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> mod_ring_rel64) (plus_p64 pp) (+)" using urel64_plus mod_ring_plus unfolding mod_ring_rel64_def rel_fun_def by blast lemma mod_ring_minus64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> mod_ring_rel64) (minus_p64 pp) (-)" using urel64_minus mod_ring_minus unfolding mod_ring_rel64_def rel_fun_def by blast lemma mod_ring_mult64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> mod_ring_rel64) (mult_p64 pp) ((*))" using urel64_mult mod_ring_mult unfolding mod_ring_rel64_def rel_fun_def by blast lemma mod_ring_eq64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> (=)) (=) (=)" using urel64_eq mod_ring_eq unfolding mod_ring_rel64_def rel_fun_def by blast lemma urel64_inj: "urel64 x y \ urel64 x z \ y = z" using urel64_eq[of x y x z] by auto lemma urel64_inj': "urel64 x z \ urel64 y z \ x = y" using urel64_eq[of x z y z] by auto lemma bi_unique_mod_ring_rel64: "bi_unique mod_ring_rel64" "left_unique mod_ring_rel64" "right_unique mod_ring_rel64" using bi_unique_mod_ring_rel urel64_inj' unfolding mod_ring_rel64_def bi_unique_def left_unique_def right_unique_def by (auto simp: urel64_def) lemma right_total_mod_ring_rel64: "right_total mod_ring_rel64" unfolding mod_ring_rel64_def right_total_def proof fix y :: "'a mod_ring" from right_total_mod_ring_rel[unfolded right_total_def, rule_format, of y] obtain z where zy: "mod_ring_rel z y" by auto hence zp: "0 \ z" "z < p" unfolding mod_ring_rel_def p using range_to_int_mod_ring[where 'a = 'a] by auto hence "urel64 (uint64_of_int z) z" unfolding urel64_def using small unfolding ppp by (auto simp: int_of_uint64_inv) with zy show "\ x z. urel64 x z \ mod_ring_rel z y" by blast qed lemma Domainp_mod_ring_rel64: "Domainp mod_ring_rel64 = (\x. 0 \ x \ x < pp)" proof fix x show "Domainp mod_ring_rel64 x = (0 \ x \ x < pp)" unfolding Domainp.simps unfolding mod_ring_rel64_def proof let ?i = "int_of_uint64" assume *: "0 \ x \ x < pp" hence "0 \ ?i x \ ?i x < p" using small unfolding ppp by (transfer, auto simp: word_less_def) hence "?i x \ {0 ..< p}" by auto with Domainp_mod_ring_rel have "Domainp mod_ring_rel (?i x)" by auto from this[unfolded Domainp.simps] obtain b where b: "mod_ring_rel (?i x) b" by auto show "\a b. x = a \ (\z. urel64 a z \ mod_ring_rel z b)" proof (intro exI, rule conjI[OF refl], rule exI, rule conjI[OF _ b]) show "urel64 x (?i x)" unfolding urel64_def using small * unfolding ppp by (transfer, auto simp: word_less_def) qed next assume "\a b. x = a \ (\z. urel64 a z \ mod_ring_rel z b)" then obtain b z where xz: "urel64 x z" and zb: "mod_ring_rel z b" by auto hence "Domainp mod_ring_rel z" by auto with Domainp_mod_ring_rel have "0 \ z" "z < p" by auto with xz show "0 \ x \ x < pp" unfolding urel64_def using small unfolding ppp by (transfer, auto simp: word_less_def) qed qed lemma ring_finite_field_ops64: "ring_ops (finite_field_ops64 pp) mod_ring_rel64" by (unfold_locales, auto simp: finite_field_ops64_def bi_unique_mod_ring_rel64 right_total_mod_ring_rel64 mod_ring_plus64 mod_ring_minus64 mod_ring_uminus64 mod_ring_mult64 mod_ring_eq64 mod_ring_0_64 mod_ring_1_64 Domainp_mod_ring_rel64) end end context prime_field begin context fixes pp :: "uint64" assumes *: "p = int_of_uint64 pp" "p \ 4294967295" begin lemma mod_ring_normalize64: "(mod_ring_rel64 ===> mod_ring_rel64) (\x. if x = 0 then 0 else 1) normalize" using urel64_normalize[OF *] mod_ring_normalize unfolding mod_ring_rel64_def[OF *] rel_fun_def by blast lemma mod_ring_mod64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> mod_ring_rel64) (\x y. if y = 0 then x else 0) (mod)" using urel64_mod[OF *] mod_ring_mod unfolding mod_ring_rel64_def[OF *] rel_fun_def by blast lemma mod_ring_unit_factor64: "(mod_ring_rel64 ===> mod_ring_rel64) (\x. x) unit_factor" using mod_ring_unit_factor unfolding mod_ring_rel64_def[OF *] rel_fun_def by blast lemma mod_ring_inverse64: "(mod_ring_rel64 ===> mod_ring_rel64) (inverse_p64 pp) inverse" using urel64_inverse[OF *] mod_ring_inverse unfolding mod_ring_rel64_def[OF *] rel_fun_def by blast lemma mod_ring_divide64: "(mod_ring_rel64 ===> mod_ring_rel64 ===> mod_ring_rel64) (divide_p64 pp) (/)" using mod_ring_inverse64 mod_ring_mult64[OF *] unfolding divide_p64_def divide_mod_ring_def inverse_mod_ring_def[symmetric] rel_fun_def by blast lemma finite_field_ops64: "field_ops (finite_field_ops64 pp) mod_ring_rel64" by (unfold_locales, insert ring_finite_field_ops64[OF *], auto simp: ring_ops_def finite_field_ops64_def mod_ring_divide64 mod_ring_inverse64 mod_ring_mod64 mod_ring_normalize64) end end (* and a final implementation via integer *) context fixes p :: integer begin definition plus_p_integer :: "integer \ integer \ integer" where "plus_p_integer x y \ let z = x + y in if z \ p then z - p else z" definition minus_p_integer :: "integer \ integer \ integer" where "minus_p_integer x y \ if y \ x then x - y else (x + p) - y" definition uminus_p_integer :: "integer \ integer" where "uminus_p_integer x = (if x = 0 then 0 else p - x)" definition mult_p_integer :: "integer \ integer \ integer" where "mult_p_integer x y = (x * y mod p)" lemma int_of_integer_0_iff: "int_of_integer n = 0 \ n = 0" using integer_eqI by auto lemma int_of_integer_0: "int_of_integer 0 = 0" unfolding int_of_integer_0_iff by simp lemma int_of_integer_plus: "int_of_integer (x + y) = (int_of_integer x + int_of_integer y)" by simp lemma int_of_integer_minus: "int_of_integer (x - y) = (int_of_integer x - int_of_integer y)" by simp lemma int_of_integer_mult: "int_of_integer (x * y) = (int_of_integer x * int_of_integer y)" by simp lemma int_of_integer_mod: "int_of_integer (x mod y) = (int_of_integer x mod int_of_integer y)" by simp lemma int_of_integer_inv: "int_of_integer (integer_of_int x) = x" by simp lemma int_of_integer_shift: "int_of_integer (drop_bit k n) = (int_of_integer n) div (2 ^ k)" by transfer (simp add: int_of_integer_pow shiftr_integer_conv_div_pow2) function power_p_integer :: "integer \ integer \ integer" where "power_p_integer x n = (if n \ 0 then 1 else let rec = power_p_integer (mult_p_integer x x) (drop_bit 1 n) in if n AND 1 = 0 then rec else mult_p_integer rec x)" by pat_completeness auto termination proof - { fix n :: integer assume "\ (n \ 0)" hence "n > 0" by auto hence "int_of_integer n > 0" by (simp add: less_integer.rep_eq) hence "0 < int_of_integer n" "int_of_integer n div 2 < int_of_integer n" by auto } note * = this show ?thesis by (relation "measure (\ (x,n). nat (int_of_integer n))", auto simp: * int_of_integer_shift) qed text \In experiments with Berlekamp-factorization (where the prime $p$ is usually small), it turned out that taking the below implementation of inverse via exponentiation is faster than the one based on the extended Euclidean algorithm.\ definition inverse_p_integer :: "integer \ integer" where "inverse_p_integer x = (if x = 0 then 0 else power_p_integer x (p - 2))" definition divide_p_integer :: "integer \ integer \ integer" where "divide_p_integer x y = mult_p_integer x (inverse_p_integer y)" definition finite_field_ops_integer :: "integer arith_ops_record" where "finite_field_ops_integer \ Arith_Ops_Record 0 1 plus_p_integer mult_p_integer minus_p_integer uminus_p_integer divide_p_integer inverse_p_integer (\ x y . if y = 0 then x else 0) (\ x . if x = 0 then 0 else 1) (\ x . x) integer_of_int int_of_integer (\ x. 0 \ x \ x < p)" end lemma shiftr_integer_code [code_unfold]: "drop_bit 1 x = (integer_shiftr x 1)" unfolding shiftr_integer_code using integer_of_nat_1 by auto text \For soundness of the integer implementation, we mainly prove that this implementation implements the int-based implementation of GF(p).\ context mod_ring_locale begin context fixes pp :: "integer" assumes ppp: "p = int_of_integer pp" begin lemmas integer_simps = int_of_integer_0 int_of_integer_plus int_of_integer_minus int_of_integer_mult definition urel_integer :: "integer \ int \ bool" where "urel_integer x y = (y = int_of_integer x \ y \ 0 \ y < p)" definition mod_ring_rel_integer :: "integer \ 'a mod_ring \ bool" where "mod_ring_rel_integer x y = (\ z. urel_integer x z \ mod_ring_rel z y)" lemma urel_integer_0: "urel_integer 0 0" unfolding urel_integer_def using p2 by simp lemma urel_integer_1: "urel_integer 1 1" unfolding urel_integer_def using p2 by simp lemma le_int_of_integer: "(x \ y) = (int_of_integer x \ int_of_integer y)" by (rule less_eq_integer.rep_eq) lemma urel_integer_plus: assumes "urel_integer x y" "urel_integer x' y'" shows "urel_integer (plus_p_integer pp x x') (plus_p p y y')" proof - let ?x = "int_of_integer x" let ?x' = "int_of_integer x'" let ?p = "int_of_integer pp" from assms have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel_integer_def by auto have le: "(pp \ x + x') = (?p \ ?x + ?x')" unfolding le_int_of_integer using rel by auto show ?thesis proof (cases "?p \ ?x + ?x'") case True hence True: "(?p \ ?x + ?x') = True" by simp show ?thesis unfolding id using rel unfolding plus_p_integer_def plus_p_def Let_def urel_integer_def unfolding ppp le True if_True using True by auto next case False hence False: "(?p \ ?x + ?x') = False" by simp show ?thesis unfolding id using rel unfolding plus_p_integer_def plus_p_def Let_def urel_integer_def unfolding ppp le False if_False using False by auto qed qed lemma urel_integer_minus: assumes "urel_integer x y" "urel_integer x' y'" shows "urel_integer (minus_p_integer pp x x') (minus_p p y y')" proof - let ?x = "int_of_integer x" let ?x' = "int_of_integer x'" from assms have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' \ p" unfolding urel_integer_def by auto have le: "(x' \ x) = (?x' \ ?x)" unfolding le_int_of_integer using rel by auto show ?thesis proof (cases "?x' \ ?x") case True hence True: "(?x' \ ?x) = True" by simp show ?thesis unfolding id using rel unfolding minus_p_integer_def minus_p_def Let_def urel_integer_def unfolding ppp le True if_True using True by auto next case False hence False: "(?x' \ ?x) = False" by simp show ?thesis unfolding id using rel unfolding minus_p_integer_def minus_p_def Let_def urel_integer_def unfolding ppp le False if_False using False by auto qed qed lemma urel_integer_uminus: assumes "urel_integer x y" shows "urel_integer (uminus_p_integer pp x) (uminus_p p y)" proof - let ?x = "int_of_integer x" from assms have id: "y = ?x" and rel: "0 \ ?x" "?x < p" unfolding urel_integer_def by auto have le: "(x = 0) = (?x = 0)" unfolding int_of_integer_0_iff using rel by auto show ?thesis proof (cases "?x = 0") case True hence True: "(?x = 0) = True" by simp show ?thesis unfolding id using rel unfolding uminus_p_integer_def uminus_p_def Let_def urel_integer_def unfolding ppp le True if_True using True by auto next case False hence False: "(?x = 0) = False" by simp show ?thesis unfolding id using rel unfolding uminus_p_integer_def uminus_p_def Let_def urel_integer_def unfolding ppp le False if_False using False by auto qed qed lemma pp_pos: "int_of_integer pp > 0" using ppp nontriv[where 'a = 'a] unfolding p by (simp add: less_integer.rep_eq) lemma urel_integer_mult: assumes "urel_integer x y" "urel_integer x' y'" shows "urel_integer (mult_p_integer pp x x') (mult_p p y y')" proof - let ?x = "int_of_integer x" let ?x' = "int_of_integer x'" from assms have id: "y = ?x" "y' = ?x'" and rel: "0 \ ?x" "?x < p" "0 \ ?x'" "?x' < p" unfolding urel_integer_def by auto from rel(1,3) have xx: "0 \ ?x * ?x'" by simp show ?thesis unfolding id using rel unfolding mult_p_integer_def mult_p_def Let_def urel_integer_def unfolding ppp mod_nonneg_pos_int[OF xx pp_pos] using xx pp_pos by simp qed lemma urel_integer_eq: assumes "urel_integer x y" "urel_integer x' y'" shows "(x = x') = (y = y')" proof - let ?x = "int_of_integer x" let ?x' = "int_of_integer x'" from assms have id: "y = ?x" "y' = ?x'" unfolding urel_integer_def by auto show ?thesis unfolding id integer_eq_iff .. qed lemma urel_integer_normalize: assumes x: "urel_integer x y" shows "urel_integer (if x = 0 then 0 else 1) (if y = 0 then 0 else 1)" unfolding urel_integer_eq[OF x urel_integer_0] using urel_integer_0 urel_integer_1 by auto lemma urel_integer_mod: assumes x: "urel_integer x x'" and y: "urel_integer y y'" shows "urel_integer (if y = 0 then x else 0) (if y' = 0 then x' else 0)" unfolding urel_integer_eq[OF y urel_integer_0] using urel_integer_0 x by auto lemma urel_integer_power: "urel_integer x x' \ urel_integer y (int y') \ urel_integer (power_p_integer pp x y) (power_p p x' y')" proof (induct x' y' arbitrary: x y rule: power_p.induct[of _ p]) case (1 x' y' x y) note x = 1(2) note y = 1(3) show ?case proof (cases "y' \ 0") case True hence y: "y = 0" "y' = 0" using urel_integer_eq[OF y urel_integer_0] by auto show ?thesis unfolding y True by (simp add: power_p.simps urel_integer_1) next case False hence id: "(y \ 0) = False" "(y' = 0) = False" using False y by (auto simp add: urel_integer_def not_le) (metis of_int_integer_of of_int_of_nat_eq of_nat_0_less_iff) obtain d' r' where dr': "Divides.divmod_nat y' 2 = (d',r')" by force from divmod_nat_def[of y' 2, unfolded dr'] have r': "r' = y' mod 2" and d': "d' = y' div 2" by auto have aux: "\ y'. int (y' mod 2) = int y' mod 2" by presburger have "urel_integer (y AND 1) r'" unfolding r' using y unfolding urel_integer_def unfolding ppp apply (auto simp add: and_one_eq) apply (simp add: of_nat_mod) done from urel_integer_eq[OF this urel_integer_0] have rem: "(y AND 1 = 0) = (r' = 0)" by simp have div: "urel_integer (drop_bit 1 y) (int d')" unfolding d' using y unfolding urel_integer_def unfolding ppp shiftr_integer_conv_div_pow2 by auto from id have "y' \ 0" by auto note IH = 1(1)[OF this refl dr'[symmetric] urel_integer_mult[OF x x] div] show ?thesis unfolding power_p.simps[of _ _ "y'"] power_p_integer.simps[of _ _ y] dr' id if_False rem using IH urel_integer_mult[OF IH x] by (auto simp: Let_def) qed qed lemma urel_integer_inverse: assumes x: "urel_integer x x'" shows "urel_integer (inverse_p_integer pp x) (inverse_p p x')" proof - have p: "urel_integer (pp - 2) (int (nat (p - 2)))" using p2 unfolding urel_integer_def unfolding ppp by auto show ?thesis unfolding inverse_p_integer_def inverse_p_def urel_integer_eq[OF x urel_integer_0] using urel_integer_0 urel_integer_power[OF x p] by auto qed lemma mod_ring_0__integer: "mod_ring_rel_integer 0 0" using urel_integer_0 mod_ring_0 unfolding mod_ring_rel_integer_def by blast lemma mod_ring_1__integer: "mod_ring_rel_integer 1 1" using urel_integer_1 mod_ring_1 unfolding mod_ring_rel_integer_def by blast lemma mod_ring_uminus_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer) (uminus_p_integer pp) uminus" using urel_integer_uminus mod_ring_uminus unfolding mod_ring_rel_integer_def rel_fun_def by blast lemma mod_ring_plus_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> mod_ring_rel_integer) (plus_p_integer pp) (+)" using urel_integer_plus mod_ring_plus unfolding mod_ring_rel_integer_def rel_fun_def by blast lemma mod_ring_minus_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> mod_ring_rel_integer) (minus_p_integer pp) (-)" using urel_integer_minus mod_ring_minus unfolding mod_ring_rel_integer_def rel_fun_def by blast lemma mod_ring_mult_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> mod_ring_rel_integer) (mult_p_integer pp) ((*))" using urel_integer_mult mod_ring_mult unfolding mod_ring_rel_integer_def rel_fun_def by blast lemma mod_ring_eq_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> (=)) (=) (=)" using urel_integer_eq mod_ring_eq unfolding mod_ring_rel_integer_def rel_fun_def by blast lemma urel_integer_inj: "urel_integer x y \ urel_integer x z \ y = z" using urel_integer_eq[of x y x z] by auto lemma urel_integer_inj': "urel_integer x z \ urel_integer y z \ x = y" using urel_integer_eq[of x z y z] by auto lemma bi_unique_mod_ring_rel_integer: "bi_unique mod_ring_rel_integer" "left_unique mod_ring_rel_integer" "right_unique mod_ring_rel_integer" using bi_unique_mod_ring_rel urel_integer_inj' unfolding mod_ring_rel_integer_def bi_unique_def left_unique_def right_unique_def by (auto simp: urel_integer_def) lemma right_total_mod_ring_rel_integer: "right_total mod_ring_rel_integer" unfolding mod_ring_rel_integer_def right_total_def proof fix y :: "'a mod_ring" from right_total_mod_ring_rel[unfolded right_total_def, rule_format, of y] obtain z where zy: "mod_ring_rel z y" by auto hence zp: "0 \ z" "z < p" unfolding mod_ring_rel_def p using range_to_int_mod_ring[where 'a = 'a] by auto hence "urel_integer (integer_of_int z) z" unfolding urel_integer_def unfolding ppp by auto with zy show "\ x z. urel_integer x z \ mod_ring_rel z y" by blast qed lemma Domainp_mod_ring_rel_integer: "Domainp mod_ring_rel_integer = (\x. 0 \ x \ x < pp)" proof fix x show "Domainp mod_ring_rel_integer x = (0 \ x \ x < pp)" unfolding Domainp.simps unfolding mod_ring_rel_integer_def proof let ?i = "int_of_integer" assume *: "0 \ x \ x < pp" hence "0 \ ?i x \ ?i x < p" unfolding ppp by (simp add: le_int_of_integer less_integer.rep_eq) hence "?i x \ {0 ..< p}" by auto with Domainp_mod_ring_rel have "Domainp mod_ring_rel (?i x)" by auto from this[unfolded Domainp.simps] obtain b where b: "mod_ring_rel (?i x) b" by auto show "\a b. x = a \ (\z. urel_integer a z \ mod_ring_rel z b)" proof (intro exI, rule conjI[OF refl], rule exI, rule conjI[OF _ b]) show "urel_integer x (?i x)" unfolding urel_integer_def using * unfolding ppp by (simp add: le_int_of_integer less_integer.rep_eq) qed next assume "\a b. x = a \ (\z. urel_integer a z \ mod_ring_rel z b)" then obtain b z where xz: "urel_integer x z" and zb: "mod_ring_rel z b" by auto hence "Domainp mod_ring_rel z" by auto with Domainp_mod_ring_rel have "0 \ z" "z < p" by auto with xz show "0 \ x \ x < pp" unfolding urel_integer_def unfolding ppp by (simp add: le_int_of_integer less_integer.rep_eq) qed qed lemma ring_finite_field_ops_integer: "ring_ops (finite_field_ops_integer pp) mod_ring_rel_integer" by (unfold_locales, auto simp: finite_field_ops_integer_def bi_unique_mod_ring_rel_integer right_total_mod_ring_rel_integer mod_ring_plus_integer mod_ring_minus_integer mod_ring_uminus_integer mod_ring_mult_integer mod_ring_eq_integer mod_ring_0__integer mod_ring_1__integer Domainp_mod_ring_rel_integer) end end context prime_field begin context fixes pp :: "integer" assumes *: "p = int_of_integer pp" begin lemma mod_ring_normalize_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer) (\x. if x = 0 then 0 else 1) normalize" using urel_integer_normalize[OF *] mod_ring_normalize unfolding mod_ring_rel_integer_def[OF *] rel_fun_def by blast lemma mod_ring_mod_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> mod_ring_rel_integer) (\x y. if y = 0 then x else 0) (mod)" using urel_integer_mod[OF *] mod_ring_mod unfolding mod_ring_rel_integer_def[OF *] rel_fun_def by blast lemma mod_ring_unit_factor_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer) (\x. x) unit_factor" using mod_ring_unit_factor unfolding mod_ring_rel_integer_def[OF *] rel_fun_def by blast lemma mod_ring_inverse_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer) (inverse_p_integer pp) inverse" using urel_integer_inverse[OF *] mod_ring_inverse unfolding mod_ring_rel_integer_def[OF *] rel_fun_def by blast lemma mod_ring_divide_integer: "(mod_ring_rel_integer ===> mod_ring_rel_integer ===> mod_ring_rel_integer) (divide_p_integer pp) (/)" using mod_ring_inverse_integer mod_ring_mult_integer[OF *] unfolding divide_p_integer_def divide_mod_ring_def inverse_mod_ring_def[symmetric] rel_fun_def by blast lemma finite_field_ops_integer: "field_ops (finite_field_ops_integer pp) mod_ring_rel_integer" by (unfold_locales, insert ring_finite_field_ops_integer[OF *], auto simp: ring_ops_def finite_field_ops_integer_def mod_ring_divide_integer mod_ring_inverse_integer mod_ring_mod_integer mod_ring_normalize_integer) end end context prime_field begin (* four implementations of modular integer arithmetic for finite fields *) thm finite_field_ops64 finite_field_ops32 finite_field_ops_integer finite_field_ops_int end context mod_ring_locale begin (* four implementations of modular integer arithmetic for finite rings *) thm ring_finite_field_ops64 ring_finite_field_ops32 ring_finite_field_ops_integer ring_finite_field_ops_int end end diff --git a/thys/Collections/GenCF/Impl/Impl_Bit_Set.thy b/thys/Collections/GenCF/Impl/Impl_Bit_Set.thy --- a/thys/Collections/GenCF/Impl/Impl_Bit_Set.thy +++ b/thys/Collections/GenCF/Impl/Impl_Bit_Set.thy @@ -1,392 +1,382 @@ section "Bitvector based Sets of Naturals" theory Impl_Bit_Set imports "../../Iterator/Iterator" "../Intf/Intf_Set" Native_Word.Bits_Integer begin text \ Based on the Native-Word library, using bit-operations on arbitrary precision integers. Fast for sets of small numbers, direct and fast implementations of equal, union, inter, diff. Note: On Poly/ML 5.5.1, bit-operations on arbitrary precision integers are rather inefficient. Use MLton instead, here they are efficiently implemented. \ type_synonym bitset = integer definition bs_\ :: "bitset \ nat set" where "bs_\ s \ { n . bit s n}" context includes integer.lifting begin definition bs_empty :: "unit \ bitset" where "bs_empty \ \_. 0" lemma bs_empty_correct: "bs_\ (bs_empty ()) = {}" unfolding bs_\_def bs_empty_def apply transfer by auto definition bs_isEmpty :: "bitset \ bool" where "bs_isEmpty s \ s=0" lemma bs_isEmpty_correct: "bs_isEmpty s \ bs_\ s = {}" unfolding bs_isEmpty_def bs_\_def - by transfer (auto simp: bin_eq_iff) + by transfer (auto simp: bit_eq_iff) term set_bit definition bs_insert :: "nat \ bitset \ bitset" where "bs_insert i s \ set_bit s i True" lemma bs_insert_correct: "bs_\ (bs_insert i s) = insert i (bs_\ s)" unfolding bs_\_def bs_insert_def - apply transfer - apply auto - apply (metis bin_nth_sc_gen bin_set_conv_OR int_set_bit_True_conv_OR) - apply (metis bin_nth_sc_gen bin_set_conv_OR int_set_bit_True_conv_OR) - by (metis bin_nth_sc_gen bin_set_conv_OR int_set_bit_True_conv_OR) + by transfer (auto simp add: bit_simps) definition bs_delete :: "nat \ bitset \ bitset" where "bs_delete i s \ set_bit s i False" lemma bs_delete_correct: "bs_\ (bs_delete i s) = (bs_\ s) - {i}" unfolding bs_\_def bs_delete_def - apply transfer - apply auto - apply (metis bin_nth_ops(1) int_set_bit_False_conv_NAND) - apply (metis (full_types) bin_nth_sc set_bit_int_def) - by (metis (full_types) bin_nth_sc_gen set_bit_int_def) + by transfer (auto simp add: bit_simps split: if_splits) definition bs_mem :: "nat \ bitset \ bool" where "bs_mem i s \ bit s i" lemma bs_mem_correct: "bs_mem i s \ i\bs_\ s" unfolding bs_mem_def bs_\_def by transfer auto definition bs_eq :: "bitset \ bitset \ bool" where "bs_eq s1 s2 \ (s1=s2)" lemma bs_eq_correct: "bs_eq s1 s2 \ bs_\ s1 = bs_\ s2" unfolding bs_eq_def bs_\_def including integer.lifting - apply transfer - apply auto - by (metis bin_eqI mem_Collect_eq) + by transfer (simp add: bit_eq_iff set_eq_iff) definition bs_subset_eq :: "bitset \ bitset \ bool" where "bs_subset_eq s1 s2 \ s1 AND NOT s2 = 0" lemma bs_subset_eq_correct: "bs_subset_eq s1 s2 \ bs_\ s1 \ bs_\ s2" unfolding bs_\_def bs_subset_eq_def - by transfer (auto simp add: bit_eq_iff bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) definition bs_disjoint :: "bitset \ bitset \ bool" where "bs_disjoint s1 s2 \ s1 AND s2 = 0" lemma bs_disjoint_correct: "bs_disjoint s1 s2 \ bs_\ s1 \ bs_\ s2 = {}" unfolding bs_\_def bs_disjoint_def - by transfer (auto simp add: bit_eq_iff bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) definition bs_union :: "bitset \ bitset \ bitset" where "bs_union s1 s2 = s1 OR s2" lemma bs_union_correct: "bs_\ (bs_union s1 s2) = bs_\ s1 \ bs_\ s2" unfolding bs_\_def bs_union_def - by transfer (auto simp: bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) definition bs_inter :: "bitset \ bitset \ bitset" where "bs_inter s1 s2 = s1 AND s2" lemma bs_inter_correct: "bs_\ (bs_inter s1 s2) = bs_\ s1 \ bs_\ s2" unfolding bs_\_def bs_inter_def - by transfer (auto simp: bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) definition bs_diff :: "bitset \ bitset \ bitset" where "bs_diff s1 s2 = s1 AND NOT s2" lemma bs_diff_correct: "bs_\ (bs_diff s1 s2) = bs_\ s1 - bs_\ s2" unfolding bs_\_def bs_diff_def - by transfer (auto simp: bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) definition bs_UNIV :: "unit \ bitset" where "bs_UNIV \ \_. -1" lemma bs_UNIV_correct: "bs_\ (bs_UNIV ()) = UNIV" unfolding bs_\_def bs_UNIV_def by transfer (auto) definition bs_complement :: "bitset \ bitset" where "bs_complement s = NOT s" lemma bs_complement_correct: "bs_\ (bs_complement s) = - bs_\ s" unfolding bs_\_def bs_complement_def - by transfer (auto simp: bin_nth_ops) + by transfer (simp add: bit_eq_iff, auto simp add: bit_simps) end lemmas bs_correct[simp] = bs_empty_correct bs_isEmpty_correct bs_insert_correct bs_delete_correct bs_mem_correct bs_eq_correct bs_subset_eq_correct bs_disjoint_correct bs_union_correct bs_inter_correct bs_diff_correct bs_UNIV_correct bs_complement_correct subsection \Autoref Setup\ definition bs_set_rel_def_internal: "bs_set_rel Rk \ if Rk=nat_rel then br bs_\ (\_. True) else {}" lemma bs_set_rel_def: "\nat_rel\bs_set_rel \ br bs_\ (\_. True)" unfolding bs_set_rel_def_internal relAPP_def by simp lemmas [autoref_rel_intf] = REL_INTFI[of "bs_set_rel" i_set] lemma bs_set_rel_sv[relator_props]: "single_valued (\nat_rel\bs_set_rel)" unfolding bs_set_rel_def by auto term bs_empty lemma [autoref_rules]: "(bs_empty (),{})\\nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_UNIV (),UNIV)\\nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_isEmpty,op_set_isEmpty)\\nat_rel\bs_set_rel \ bool_rel" by (auto simp: bs_set_rel_def br_def) term insert lemma [autoref_rules]: "(bs_insert,insert)\nat_rel \ \nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) term op_set_delete lemma [autoref_rules]: "(bs_delete,op_set_delete)\nat_rel \ \nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_mem,(\))\nat_rel \ \nat_rel\bs_set_rel \ bool_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_eq,(=))\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ bool_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_subset_eq,(\))\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ bool_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_union,(\))\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_inter,(\))\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_diff,(-))\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_complement,uminus)\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel" by (auto simp: bs_set_rel_def br_def) lemma [autoref_rules]: "(bs_disjoint,op_set_disjoint)\\nat_rel\bs_set_rel \ \nat_rel\bs_set_rel \ bool_rel" by (auto simp: bs_set_rel_def br_def) export_code bs_empty bs_isEmpty bs_insert bs_delete bs_mem bs_eq bs_subset_eq bs_disjoint bs_union bs_inter bs_diff bs_UNIV bs_complement in SML (* TODO: Iterator definition "maxbi s \ GREATEST i. s!!i" lemma cmp_BIT_append_conv[simp]: "i < i BIT b \ ((i\0 \ b=1) \ i>0)" by (cases b) (auto simp: Bit_B0 Bit_B1) lemma BIT_append_cmp_conv[simp]: "i BIT b < i \ ((i<0 \ (i=-1 \ b=0)))" by (cases b) (auto simp: Bit_B0 Bit_B1) lemma BIT_append_eq[simp]: fixes i :: int shows "i BIT b = i \ (i=0 \ b=0) \ (i=-1 \ b=1)" by (cases b) (auto simp: Bit_B0 Bit_B1) lemma int_no_bits_eq_zero[simp]: fixes s::int shows "(\i. \s!!i) \ s=0" apply clarsimp by (metis bin_eqI bin_nth_code(1)) lemma int_obtain_bit: fixes s::int assumes "s\0" obtains i where "s!!i" by (metis assms int_no_bits_eq_zero) lemma int_bit_bound: fixes s::int assumes "s\0" and "s!!i" shows "i \ Bits_Integer.log2 s" proof (rule ccontr) assume "\i\Bits_Integer.log2 s" hence "i>Bits_Integer.log2 s" by simp hence "i - 1 \ Bits_Integer.log2 s" by simp hence "s AND bin_mask (i - 1) = s" by (simp add: int_and_mask `s\0`) hence "\ (s!!i)" by clarsimp (metis Nat.diff_le_self bin_nth_mask bin_nth_ops(1) leD) thus False using `s!!i` .. qed lemma int_bit_bound': fixes s::int assumes "s\0" and "s!!i" shows "i < Bits_Integer.log2 s + 1" using assms int_bit_bound by smt lemma int_obtain_bit_pos: fixes s::int assumes "s>0" obtains i where "s!!i" "i < Bits_Integer.log2 s + 1" by (metis assms int_bit_bound' int_no_bits_eq_zero less_imp_le less_irrefl) lemma maxbi_set: fixes s::int shows "s>0 \ s!!maxbi s" unfolding maxbi_def apply (rule int_obtain_bit_pos, assumption) apply (rule GreatestI_nat, assumption) apply (intro allI impI) apply (rule int_bit_bound'[rotated], assumption) by auto lemma maxbi_max: fixes s::int shows "i>maxbi s \ \ s!!i" oops function get_maxbi :: "nat \ int \ nat" where "get_maxbi n s = (let b = 1<s then get_maxbi (n+1) s else n )" by pat_completeness auto termination apply (rule "termination"[of "measure (\(n,s). nat (s + 1 - (1< bitset \ ('\ \ bool) \ (nat \ '\ \ '\) \ '\ \ '\" where "bs_iterate_aux i s c f \ = ( if s < 1 << i then \ else if \c \ then \ else if test_bit s i then bs_iterate_aux (i+1) s c f (f i \) else bs_iterate_aux (i+1) s c f \ )" definition bs_iteratei :: "bitset \ (nat,'\) set_iterator" where "bs_iteratei s = bs_iterate_aux 0 s" definition bs_set_rel_def_internal: "bs_set_rel Rk \ if Rk=nat_rel then br bs_\ (\_. True) else {}" lemma bs_set_rel_def: "\nat_rel\bs_set_rel \ br bs_\ (\_. True)" unfolding bs_set_rel_def_internal relAPP_def by simp definition "bs_to_list \ it_to_list bs_iteratei" lemma "(1::int)<0" shows "s < 1< Bits_Integer.log2 s \ i" using assms proof (induct i arbitrary: s) case 0 thus ?case by auto next case (Suc i) note GE=`0\s` show ?case proof assume "s < 1 << Suc i" have "s \ (s >> 1) BIT 1" hence "(s >> 1) < (1<_. True) (\x l. l @ [x]) [])" } apply auto lemma "set (bs_to_list s) = bs_\ s" lemma autoref_iam_is_iterator[autoref_ga_rules]: shows "is_set_to_list nat_rel bs_set_rel bs_to_list" unfolding is_set_to_list_def is_set_to_sorted_list_def apply clarsimp unfolding it_to_sorted_list_def apply (refine_rcg refine_vcg) apply (simp_all add: bs_set_rel_def br_def) proof (clarsimp) definition "iterate s c f \ \ let i=0; b=0; (_,_,s) = while in end" *) end diff --git a/thys/Collections/GenCF/Impl/Impl_Uv_Set.thy b/thys/Collections/GenCF/Impl/Impl_Uv_Set.thy --- a/thys/Collections/GenCF/Impl/Impl_Uv_Set.thy +++ b/thys/Collections/GenCF/Impl/Impl_Uv_Set.thy @@ -1,396 +1,396 @@ theory Impl_Uv_Set imports "../../Iterator/Iterator" "../Intf/Intf_Set" Native_Word.Uint begin subsection \Bit-Vectors as Lists of Words\ subsubsection \Lookup\ primrec lookup :: "nat \ ('a::len) word list \ bool" where "lookup _ [] \ False" | "lookup n (w#ws) \ (if n ( if n < LENGTH('a) * length w1 then lookup n w1 else lookup (n - LENGTH('a) * length w1) w2)" by (induction w1 arbitrary: n) auto lemma lookup_zeroes[simp]: "lookup i (replicate n (0::'a::len word)) = False" by (induction n arbitrary: i) auto lemma lookup_out_of_bound: fixes uv :: "'a::len word list" assumes "\ i < LENGTH('a::len) * length uv" shows "\ lookup i uv" using assms by (induction uv arbitrary: i) auto subsubsection \Empty\ definition empty :: "'a::len word list" where "empty = []" subsubsection \Set and Reset Bit\ function single_bit :: "nat \ ('a::len) word list" where "single_bit n = ( if (n i = n" apply (induction n arbitrary: i rule: single_bit.induct) apply (subst single_bit.simps) - apply (auto simp: bin_nth_sc_gen bit_simps) + apply (auto simp add: bit_simps) done primrec set_bit :: "nat \ 'a::len word list \ 'a::len word list" where "set_bit i [] = single_bit i" | "set_bit i (w#ws) = ( if i (lookup i ws \ i=j)" apply (induction ws arbitrary: i j) apply (auto simp add: word_size Bit_Operations.bit_set_bit_iff) done primrec reset_bit :: "nat \ 'a::len word list \ 'a::len word list" where "reset_bit i [] = []" | "reset_bit i (w#ws) = ( if i (lookup i ws \ i\j)" apply (induction ws arbitrary: i j) apply (auto simp: word_size bit_unset_bit_iff) done subsubsection \Binary Operations\ definition is_bin_op_impl :: "(bool\bool\bool) \ ('a::len word \ 'a::len word \ 'a::len word) \ bool" where "is_bin_op_impl f g \ (\w v. \i f (bit w i) (bit v i))" definition "is_strict_bin_op_impl f g \ is_bin_op_impl f g \ f False False = False" fun binary :: "('a::len word \ 'a::len word \ 'a::len word) \ 'a::len word list \ 'a::len word list \ 'a::len word list" where "binary f [] [] = []" | "binary f [] (w#ws) = f 0 w # binary f [] ws" | "binary f (v#vs) [] = f v 0 # binary f vs []" | "binary f (v#vs) (w#ws) = f v w # binary f vs ws" lemma binary_lookup: assumes "is_strict_bin_op_impl f g" shows "lookup i (binary g ws vs) \ f (lookup i ws) (lookup i vs)" using assms apply (induction g ws vs arbitrary: i rule: binary.induct) apply (auto simp: is_strict_bin_op_impl_def is_bin_op_impl_def) done subsection \Abstraction to Sets of Naturals\ definition "\ uv \ {n. lookup n uv}" lemma memb_correct: "lookup i ws \ i\\ ws" by (auto simp: \_def) lemma empty_correct: "\ empty = {}" by (simp add: \_def empty_def) lemma single_bit_correct: "\ (single_bit n) = {n}" by (simp add: \_def) lemma insert_correct: "\ (set_bit i ws) = Set.insert i (\ ws)" by (auto simp add: \_def) lemma delete_correct: "\ (reset_bit i ws) = (\ ws) - {i}" by (auto simp add: \_def) lemma binary_correct: assumes "is_strict_bin_op_impl f g" shows "\ (binary g ws vs) = { i . f (i\\ ws) (i\\ vs) }" unfolding \_def by (auto simp add: binary_lookup[OF assms]) fun union :: "'a::len word list \ 'a::len word list \ 'a::len word list" where "union [] ws = ws" | "union vs [] = vs" | "union (v#vs) (w#ws) = (v OR w) # union vs ws" lemma union_lookup[simp]: fixes vs :: "'a::len word list" shows "lookup i (union vs ws) \ lookup i vs \ lookup i ws" apply (induction vs ws arbitrary: i rule: union.induct) apply (auto simp: word_ao_nth) done lemma union_correct: "\ (union ws vs) = \ ws \ \ vs" by (auto simp add: \_def) fun inter :: "'a::len word list \ 'a::len word list \ 'a::len word list" where "inter [] ws = []" | "inter vs [] = []" | "inter (v#vs) (w#ws) = (v AND w) # inter vs ws" lemma inter_lookup[simp]: fixes vs :: "'a::len word list" shows "lookup i (inter vs ws) \ lookup i vs \ lookup i ws" apply (induction vs ws arbitrary: i rule: inter.induct) apply (auto simp: word_ao_nth) done lemma inter_correct: "\ (inter ws vs) = \ ws \ \ vs" by (auto simp add: \_def) fun diff :: "'a::len word list \ 'a::len word list \ 'a::len word list" where "diff [] ws = []" | "diff vs [] = vs" | "diff (v#vs) (w#ws) = (v AND NOT w) # diff vs ws" lemma diff_lookup[simp]: fixes vs :: "'a::len word list" shows "lookup i (diff vs ws) \ lookup i vs - lookup i ws" apply (induction vs ws arbitrary: i rule: diff.induct) apply (auto simp: word_ops_nth_size word_size) done lemma diff_correct: "\ (diff ws vs) = \ ws - \ vs" by (auto simp add: \_def) fun zeroes :: "'a::len word list \ bool" where "zeroes [] \ True" | "zeroes (w#ws) \ w=0 \ zeroes ws" lemma zeroes_lookup: "zeroes ws \ (\i. \lookup i ws)" apply (induction ws) apply (auto simp: word_eq_iff) by (metis diff_add_inverse2 not_add_less2) lemma isEmpty_correct: "zeroes ws \ \ ws = {}" by (auto simp: zeroes_lookup \_def) fun equal :: "'a::len word list \ 'a::len word list \ bool" where "equal [] [] \ True" | "equal [] ws \ zeroes ws" | "equal vs [] \ zeroes vs" | "equal (v#vs) (w#ws) \ v=w \ equal vs ws" lemma equal_lookup: fixes vs ws :: "'a::len word list" shows "equal vs ws \ (\i. lookup i vs = lookup i ws)" proof (induction vs ws rule: equal.induct) fix v w and vs ws :: "'a::len word list" assume IH: "equal vs ws = (\i. lookup i vs = lookup i ws)" show "equal (v # vs) (w # ws) = (\i. lookup i (v # vs) = lookup i (w # ws))" proof (rule iffI, rule allI) fix i assume "equal (v#vs) (w#ws)" thus "lookup i (v # vs) = lookup i (w # ws)" by (auto simp: IH) next assume "\i. lookup i (v # vs) = lookup i (w # ws)" thus "equal (v # vs) (w # ws)" apply (auto simp: word_eq_iff IH) apply metis apply metis apply (drule_tac x="i + LENGTH('a)" in spec) apply auto [] apply (drule_tac x="i + LENGTH('a)" in spec) apply auto [] done qed qed (auto simp: zeroes_lookup) lemma equal_correct: "equal vs ws \ \ vs = \ ws" by (auto simp: \_def equal_lookup) fun subseteq :: "'a::len word list \ 'a::len word list \ bool" where "subseteq [] ws \ True" | "subseteq vs [] \ zeroes vs" | "subseteq (v#vs) (w#ws) \ (v AND NOT w = 0) \ subseteq vs ws" lemma subseteq_lookup: fixes vs ws :: "'a::len word list" shows "subseteq vs ws \ (\i. lookup i vs \ lookup i ws)" apply (induction vs ws rule: subseteq.induct) apply simp apply (auto simp: zeroes_lookup) [] apply (auto simp: word_ops_nth_size word_size word_eq_iff) by (metis diff_add_inverse2 not_add_less2) lemma subseteq_correct: "subseteq vs ws \ \ vs \ \ ws" by (auto simp: \_def subseteq_lookup) fun subset :: "'a::len word list \ 'a::len word list \ bool" where "subset [] ws \ \zeroes ws" | "subset vs [] \ False" | "subset (v#vs) (w#ws) \ (if v=w then subset vs ws else subseteq (v#vs) (w#ws))" lemma subset_lookup: fixes vs ws :: "'a::len word list" shows "subset vs ws \ ((\i. lookup i vs \ lookup i ws) \ (\i. \lookup i vs \ lookup i ws))" apply (induction vs ws rule: subset.induct) apply (simp add: zeroes_lookup) apply (simp add: zeroes_lookup) [] apply (simp add: subseteq_lookup) apply safe apply simp_all apply (auto simp: word_ops_nth_size word_size word_eq_iff) done lemma subset_correct: "subset vs ws \ \ vs \ \ ws" by (auto simp: \_def subset_lookup) fun disjoint :: "'a::len word list \ 'a::len word list \ bool" where "disjoint [] ws \ True" | "disjoint vs [] \ True" | "disjoint (v#vs) (w#ws) \ (v AND w = 0) \ disjoint vs ws" lemma disjoint_lookup: fixes vs ws :: "'a::len word list" shows "disjoint vs ws \ (\i. \(lookup i vs \ lookup i ws))" apply (induction vs ws rule: disjoint.induct) apply simp apply simp apply (auto simp: word_ops_nth_size word_size word_eq_iff) by (metis diff_add_inverse2 not_add_less2) lemma disjoint_correct: "disjoint vs ws \ \ vs \ \ ws = {}" by (auto simp: \_def disjoint_lookup) subsection \Lifting to Uint\ type_synonym uint_vector = "uint list" lift_definition uv_\ :: "uint_vector \ nat set" is \ . lift_definition uv_lookup :: "nat \ uint_vector \ bool" is lookup . lift_definition uv_empty :: "uint_vector" is empty . lift_definition uv_single_bit :: "nat \ uint_vector" is single_bit . lift_definition uv_set_bit :: "nat \ uint_vector \ uint_vector" is set_bit . lift_definition uv_reset_bit :: "nat \ uint_vector \ uint_vector" is reset_bit . lift_definition uv_union :: "uint_vector \ uint_vector \ uint_vector" is union . lift_definition uv_inter :: "uint_vector \ uint_vector \ uint_vector" is inter . lift_definition uv_diff :: "uint_vector \ uint_vector \ uint_vector" is diff . lift_definition uv_zeroes :: "uint_vector \ bool" is zeroes . lift_definition uv_equal :: "uint_vector \ uint_vector \ bool" is equal . lift_definition uv_subseteq :: "uint_vector \ uint_vector \ bool" is subseteq . lift_definition uv_subset :: "uint_vector \ uint_vector \ bool" is subset . lift_definition uv_disjoint :: "uint_vector \ uint_vector \ bool" is disjoint . lemmas uv_memb_correct = memb_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_empty_correct = empty_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_single_bit_correct = single_bit_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_insert_correct = insert_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_delete_correct = delete_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_union_correct = union_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_inter_correct = inter_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_diff_correct = diff_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_isEmpty_correct = isEmpty_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_equal_correct = equal_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_subseteq_correct = subseteq_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_subset_correct = subset_correct[where 'a=dflt_size, Transfer.transferred] lemmas uv_disjoint_correct = disjoint_correct[where 'a=dflt_size, Transfer.transferred] lemmas [where 'a=dflt_size, Transfer.transferred, code] = lookup.simps empty_def single_bit.simps set_bit.simps reset_bit.simps union.simps inter.simps diff.simps zeroes.simps equal.simps subseteq.simps subset.simps disjoint.simps hide_const (open) \ lookup empty single_bit set_bit reset_bit union inter diff zeroes equal subseteq subset disjoint subsection \Autoref Setup\ definition uv_set_rel_def_internal: "uv_set_rel Rk \ if Rk=nat_rel then br uv_\ (\_. True) else {}" lemma uv_set_rel_def: "\nat_rel\uv_set_rel \ br uv_\ (\_. True)" unfolding uv_set_rel_def_internal relAPP_def by simp lemmas [autoref_rel_intf] = REL_INTFI[of "uv_set_rel" i_set] lemma uv_set_rel_sv[relator_props]: "single_valued (\nat_rel\uv_set_rel)" unfolding uv_set_rel_def by auto lemma uv_autoref[autoref_rules,param]: "(uv_lookup,(\)) \ nat_rel \ \nat_rel\uv_set_rel \ bool_rel" "(uv_empty,{}) \ \nat_rel\uv_set_rel" "(uv_set_bit,insert) \ nat_rel \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel" "(uv_reset_bit,op_set_delete) \ nat_rel \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel" "(uv_union,(\)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel" "(uv_inter,(\)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel" "(uv_diff,(-)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel" "(uv_zeroes,op_set_isEmpty) \ \nat_rel\uv_set_rel \ bool_rel" "(uv_equal,(=)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ bool_rel" "(uv_subseteq,(\)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ bool_rel" "(uv_subset,(\)) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ bool_rel" "(uv_disjoint,op_set_disjoint) \ \nat_rel\uv_set_rel \ \nat_rel\uv_set_rel \ bool_rel" by (auto simp: uv_set_rel_def br_def simp: uv_memb_correct uv_empty_correct uv_insert_correct uv_delete_correct simp: uv_union_correct uv_inter_correct uv_diff_correct uv_isEmpty_correct simp: uv_equal_correct uv_subseteq_correct uv_subset_correct uv_disjoint_correct) export_code uv_lookup uv_empty uv_single_bit uv_set_bit uv_reset_bit uv_union uv_inter uv_diff uv_zeroes uv_equal uv_subseteq uv_subset uv_disjoint checking SML Scala Haskell? OCaml? end diff --git a/thys/Mersenne_Primes/Lucas_Lehmer_Code.thy b/thys/Mersenne_Primes/Lucas_Lehmer_Code.thy --- a/thys/Mersenne_Primes/Lucas_Lehmer_Code.thy +++ b/thys/Mersenne_Primes/Lucas_Lehmer_Code.thy @@ -1,268 +1,268 @@ section \Efficient code for testing Mersenne primes\ theory Lucas_Lehmer_Code imports Lucas_Lehmer "HOL-Library.Code_Target_Numeral" "Native_Word.Code_Target_Bits_Int" begin subsection \Efficient computation of remainders modulo a Mersenne number\ text \ We have $k = k\ \text{mod}\ 2^n + k\ \text{div}\ 2^n\ \ (\text{mod}\ (2^n - 1))$, and $k\ \text{mod}\ 2^n = k\, \&\, (2^n - 1)$ and $k\ \text{div}\ 2^n = k \gg n$. Therefore, we can reduce $k$ modulo $2^n - 1$ using only bitwise operations, addition, and bit shifts. \ lemma cong_mersenne_number_int: fixes k :: int shows "[k mod 2 ^ n + k div 2 ^ n = k] (mod (2 ^ n - 1))" proof - have "k = (2 ^ n - 1 + 1) * (k div 2 ^ n) + (k mod 2 ^ n)" by simp also have "[\ = (0 + 1) * (k div 2 ^ n) + (k mod 2 ^ n)] (mod (2 ^ n - 1))" by (intro cong_add cong_mult cong_refl) (auto simp: cong_def) finally show ?thesis by (simp add: cong_sym add_ac) qed text \ We encapsulate a single reduction step in the following operation. Note, however, that the result is not, in general, the same as $k\ \text{mod}\ (2^n - 1)$. Multiple reductions might be required in order to reduce it below $2^n$, and a multiple of $2 ^ n - 1$ can be reduced to $2 ^ n - 1$, which is invariant to further reduction steps. \ definition mersenne_mod :: "int \ nat \ int" where "mersenne_mod k n = k mod 2 ^ n + k div 2 ^ n" lemma mersenne_mod_code [code]: - "mersenne_mod k n = (k AND ((push_bit n 1) - 1)) + (drop_bit n k)" - by (simp add: mersenne_mod_def shiftr_int_def shiftl_int_def AND_mod) + "mersenne_mod k n = take_bit n k + drop_bit n k" + by (simp add: mersenne_mod_def flip: take_bit_eq_mod drop_bit_eq_div) lemma cong_mersenne_mod: "[mersenne_mod k n = k] (mod (2 ^ n - 1))" unfolding mersenne_mod_def by (rule cong_mersenne_number_int) lemma mersenne_mod_nonneg [simp]: "k \ 0 \ mersenne_mod k n \ 0" unfolding mersenne_mod_def by (intro add_nonneg_nonneg) (simp_all add: pos_imp_zdiv_nonneg_iff) lemma mersenne_mod_less: assumes "k \ 2 ^ m" "m \ n" shows "mersenne_mod k n < 2 ^ n + 2 ^ (m - n)" proof - have "mersenne_mod k n = k mod 2 ^ n + k div 2 ^ n" by (simp add: mersenne_mod_def) also have "k mod 2 ^ n < 2 ^ n" by simp also { have "k div 2 ^ n * 2 ^ n + 0 \ k div 2 ^ n * 2 ^ n + k mod (2 ^ n)" by (intro add_mono) auto also have "\ = k" by (subst mult.commute) auto also have "\ \ 2 ^ m" using assms by simp also have "\ = 2 ^ (m - n) * 2 ^ n" using assms by (simp flip: power_add) finally have "k div 2 ^ n \ 2 ^ (m - n)" by simp } finally show ?thesis by simp qed lemma mersenne_mod_less': assumes "k \ 5 * 2 ^ n" shows "mersenne_mod k n < 2 ^ n + 5" proof - have "mersenne_mod k n = k mod 2 ^ n + k div 2 ^ n" by (simp add: mersenne_mod_def) also have "k mod 2 ^ n < 2 ^ n" by simp also { have "k div 2 ^ n * 2 ^ n + 0 \ k div 2 ^ n * 2 ^ n + k mod (2 ^ n)" by (intro add_mono) auto also have "\ = k" by (subst mult.commute) auto also have "\ \ 5 * 2 ^ n" using assms by simp finally have "k div 2 ^ n \ 5" by simp } finally show ?thesis by simp qed text \ It turns out that for our use case, a single reduction is not enough to reduce the number in question enough (or at least I was unable to prove that it is). We therefore perform two reduction steps, which is enough to guarantee that our numbers are below $2^n + 4$ before and after every step in the Lucas--Lehmer sequence. Whether one or two reductions are performed is not very important anyway, since the dominant step is the squaring anyway. \ definition mersenne_mod2 :: "int \ nat \ int" where "mersenne_mod2 k n = mersenne_mod (mersenne_mod k n) n" lemma cong_mersenne_mod2: "[mersenne_mod2 k n = k] (mod (2 ^ n - 1))" unfolding mersenne_mod2_def by (rule cong_trans) (rule cong_mersenne_mod)+ lemma mersenne_mod2_nonneg [simp]: "k \ 0 \ mersenne_mod2 k n \ 0" unfolding mersenne_mod2_def by simp lemma mersenne_mod2_less: assumes "n > 2" and "k \ 2 ^ (2 * n + 2)" shows "mersenne_mod2 k n < 2 ^ n + 5" proof - from assms have "2 ^ 3 \ (2 ^ n :: int)" by (intro power_increasing) auto hence "2 ^ n \ (8 :: int)" by simp have "mersenne_mod k n < 2 ^ n + 2 ^ (2 * n + 2 - n)" by (rule mersenne_mod_less) (use assms in auto) also have "\ \ 5 * 2 ^ n" by (simp add: power_add) finally have "mersenne_mod (mersenne_mod k n) n < 2 ^ n + 5" by (intro mersenne_mod_less') auto thus ?thesis by (simp add: mersenne_mod2_def) qed text \ Since we subtract 2 at one point, the intermediate results can become negative. This is not a problem since our reduction modulo $2 ^ p - 1$ happens to make them positive again immediately. \ lemma mersenne_mod_nonneg_strong: assumes "a > -(2 ^ p) + 1" shows "mersenne_mod a p \ 0" proof (cases "a < 0") case True have "eucl_rel_int a (2 ^ p) (- 1, a + 2 ^ p)" using assms True by (auto simp: eucl_rel_int_iff) hence "a div 2 ^ p = -1" and "a mod 2 ^ p = a + 2 ^ p" by (simp_all add: div_int_unique mod_int_unique) hence "mersenne_mod a p = a + 2 ^ p - 1" by (simp add: mersenne_mod_def) also have "\ > 0" using assms by simp finally show ?thesis by simp qed auto lemma mersenne_mod2_nonneg_strong: assumes "a > -(2 ^ p) + 1" shows "mersenne_mod2 a p \ 0" unfolding mersenne_mod2_def by (rule mersenne_mod_nonneg, rule mersenne_mod_nonneg_strong) (use assms in auto) subsection \Efficient code for the Lucas--Lehmer sequence\ primrec gen_lucas_lehmer_sequence'' :: "nat \ int \ nat \ int" where "gen_lucas_lehmer_sequence'' p a 0 = a" | "gen_lucas_lehmer_sequence'' p a (Suc n) = gen_lucas_lehmer_sequence'' p (mersenne_mod2 (a ^ 2 - 2) p) n" lemma gen_lucas_lehmer_sequence''_correct: assumes "[a = a'] (mod (2 ^ p - 1))" shows "[gen_lucas_lehmer_sequence'' p a n = gen_lucas_lehmer_sequence a' n] (mod (2 ^ p - 1))" using assms proof (induction n arbitrary: a a') case (Suc n) have "[mersenne_mod2 (a ^ 2 - 2) p = a ^ 2 - 2] (mod (2 ^ p - 1))" by (rule cong_mersenne_mod2) also have "[a ^ 2 - 2 = a' ^ 2 - 2] (mod (2 ^ p - 1))" by (intro cong_pow cong_diff Suc.prems cong_refl) finally have "[gen_lucas_lehmer_sequence'' p (mersenne_mod2 (a\<^sup>2 - 2) p) n = gen_lucas_lehmer_sequence (a'\<^sup>2 - 2) n] (mod 2 ^ p - 1)" by (rule Suc.IH) thus ?case by (auto simp del: gen_lucas_lehmer_sequence.simps simp: gen_lucas_lehmer_sequence_Suc') qed auto lemma gen_lucas_lehmer_sequence''_bounds: assumes "a \ 0" "a < 2 ^ p + 5" "p > 2" shows "gen_lucas_lehmer_sequence'' p a n \ {0..<2 ^ p + 5}" using assms proof (induction n arbitrary: a) case (Suc n) from Suc.prems have "a ^ 2 < (2 ^ p + 5) ^ 2" by (intro power_strict_mono Suc.prems) auto also have "\ \ (2 ^ (p + 1)) ^ 2" using power_increasing[of 3 p "2 :: int"] \p > 2\ by (intro power_mono) auto finally have "a ^ 2 - 2 < 2 ^ (2 * p + 2)" by (simp flip: power_mult mult_ac) moreover { from \p > 2\ have "(2 ^ p) \ (2 ^ 3 :: int)" by (intro power_increasing) auto hence "-(2 ^ p) + 1 < (-2 :: int)" by simp also have "-2 \ a ^ 2 - 2" by simp finally have "mersenne_mod2 (a ^ 2 - 2) p \ 0" by (rule mersenne_mod2_nonneg_strong) } ultimately have "gen_lucas_lehmer_sequence'' p (mersenne_mod2 (a\<^sup>2 - 2) p) n \ {0..<2 ^ p + 5}" using \p > 2\ by (intro Suc.IH mersenne_mod2_less) auto thus ?case by simp qed auto subsection \Code for the Lucas--Lehmer test\ lemmas [code del] = lucas_lehmer_test_code_arithmetic lemma lucas_lehmer_test_code [code]: "lucas_lehmer_test p = (2 < p \ (let x = gen_lucas_lehmer_sequence'' p 4 (p - 2) in x = 0 \ x = (push_bit p 1) - 1))" unfolding lucas_lehmer_test_def proof (rule conj_cong) assume "p > 2" define x where "x = gen_lucas_lehmer_sequence'' p 4 (p - 2)" from \p > 2\ have "2 ^ 3 \ (2 ^ p :: int)" by (intro power_increasing) auto hence "2 ^ p \ (8 :: int)" by simp hence bounds: "x \ {0..<2 ^ p + 5}" unfolding x_def using \p > 2\ by (intro gen_lucas_lehmer_sequence''_bounds) auto have "2 ^ p - 1 dvd gen_lucas_lehmer_sequence 4 (p - 2) \ 2 ^ p - 1 dvd x" unfolding x_def by (intro cong_dvd_iff cong_sym[OF gen_lucas_lehmer_sequence''_correct]) auto also have "\ \ x \ {0, 2 ^ p - 1}" proof assume "2 ^ p - 1 dvd x" then obtain k where k: "x = (2 ^ p - 1) * k" by auto have "k \ 0" using bounds \2 ^ p \ 8\ by (auto simp: k zero_le_mult_iff) moreover { have "x < 2 ^ p + 5" using bounds by simp also have "\ \ (2 ^ p - 1) * 2" using \2 ^ p \ 8\ by simp finally have "(2 ^ p - 1) * k < (2 ^ p - 1) * 2" unfolding k . hence "k < 2" by (subst (asm) mult_less_cancel_left) auto } ultimately have "k = 0 \ k = 1" by auto thus "x \ {0, 2 ^ p - 1}" using k by auto qed auto finally show "(2 ^ p - 1 dvd gen_lucas_lehmer_sequence 4 (p - 2)) = ((let x = x in x = 0 \ x = (push_bit p 1) - 1))" - by (simp add: shiftl_int_def Let_def) + by (simp add: Let_def push_bit_eq_mult) qed auto subsection \Examples\ text \ Note that for some reason, the clever bit-arithmetic version of the Lucas--Lehmer test is actually much slower than the one using integer arithmetic when using PolyML, and even more so when using the built-in evaluator in Isabelle (which also uses PolyML with a slightly different setup). I do not quite know why this is the case, but it is likely because of inefficient implementations of bit arithmetic operations in PolyML and/or the code generator setup for it. When running with GHC, the bit-arithmetic version is \<^emph>\much\ faster. \ value "filter mersenne_prime [0..<100]" lemma "prime (2 ^ 521 - 1 :: nat)" by (subst lucas_lehmer_correct') eval lemma "prime (2 ^ 4253 - 1 :: nat)" by (subst lucas_lehmer_correct') eval end \ No newline at end of file diff --git a/thys/Native_Word/Bits_Integer.thy b/thys/Native_Word/Bits_Integer.thy --- a/thys/Native_Word/Bits_Integer.thy +++ b/thys/Native_Word/Bits_Integer.thy @@ -1,669 +1,667 @@ (* Title: Bits_Integer.thy Author: Andreas Lochbihler, ETH Zurich *) chapter \Bit operations for target language integers\ theory Bits_Integer imports "Word_Lib.Bit_Comprehension" Code_Int_Integer_Conversion Code_Symbolic_Bits_Int begin lemmas [transfer_rule] = identity_quotient fun_quotient Quotient_integer[folded integer.pcr_cr_eq] lemma undefined_transfer: assumes "Quotient R Abs Rep T" shows "T (Rep undefined) undefined" using assms unfolding Quotient_alt_def by blast bundle undefined_transfer = undefined_transfer[transfer_rule] section \More lemmas about @{typ integer}s\ context includes integer.lifting begin lemma bitval_integer_transfer [transfer_rule]: "(rel_fun (=) pcr_integer) of_bool of_bool" by(auto simp add: of_bool_def integer.pcr_cr_eq cr_integer_def) lemma integer_of_nat_less_0_conv [simp]: "\ integer_of_nat n < 0" by(transfer) simp lemma int_of_integer_pow: "int_of_integer (x ^ n) = int_of_integer x ^ n" by(induct n) simp_all lemma pow_integer_transfer [transfer_rule]: "(rel_fun pcr_integer (rel_fun (=) pcr_integer)) (^) (^)" by(auto 4 3 simp add: integer.pcr_cr_eq cr_integer_def int_of_integer_pow) lemma sub1_lt_0_iff [simp]: "Code_Numeral.sub n num.One < 0 \ False" by(cases n)(simp_all add: Code_Numeral.sub_code) lemma nat_of_integer_numeral [simp]: "nat_of_integer (numeral n) = numeral n" by transfer simp lemma nat_of_integer_sub1_conv_pred_numeral [simp]: "nat_of_integer (Code_Numeral.sub n num.One) = pred_numeral n" by(cases n)(simp_all add: Code_Numeral.sub_code) lemma nat_of_integer_1 [simp]: "nat_of_integer 1 = 1" by transfer simp lemma dup_1 [simp]: "Code_Numeral.dup 1 = 2" by transfer simp section \Bit operations on @{typ integer}\ text \Bit operations on @{typ integer} are the same as on @{typ int}\ lift_definition bin_rest_integer :: "integer \ integer" is \\k . k div 2\ . lift_definition bin_last_integer :: "integer \ bool" is odd . lift_definition Bit_integer :: "integer \ bool \ integer" is \\k b. of_bool b + 2 * k\ . end instantiation integer :: lsb begin context includes integer.lifting begin lift_definition lsb_integer :: "integer \ bool" is lsb . instance by (standard; transfer) (fact lsb_odd) end end instantiation integer :: msb begin context includes integer.lifting begin lift_definition msb_integer :: "integer \ bool" is msb . instance .. end end instantiation integer :: set_bit begin context includes integer.lifting begin lift_definition set_bit_integer :: "integer \ nat \ bool \ integer" is set_bit . instance apply standard apply transfer apply (simp add: bit_simps) done end end abbreviation (input) wf_set_bits_integer where "wf_set_bits_integer \ wf_set_bits_int" section \Target language implementations\ text \ Unfortunately, this is not straightforward, because these API functions have different signatures and preconditions on the parameters: \begin{description} \item[Standard ML] Shifts in IntInf are given as word, but not IntInf. \item[Haskell] In the Data.Bits.Bits type class, shifts and bit indices are given as Int rather than Integer. \end{description} Additional constants take only parameters of type @{typ integer} rather than @{typ nat} and check the preconditions as far as possible (e.g., being non-negative) in a portable way. Manual implementations inside code\_printing perform the remaining range checks and convert these @{typ integer}s into the right type. For normalisation by evaluation, we derive custom code equations, because NBE does not know these code\_printing serialisations and would otherwise loop. \ code_identifier code_module Bits_Integer \ (SML) Bits_Int and (OCaml) Bits_Int and (Haskell) Bits_Int and (Scala) Bits_Int code_printing code_module Bits_Integer \ (SML) \structure Bits_Integer : sig val set_bit : IntInf.int -> IntInf.int -> bool -> IntInf.int val shiftl : IntInf.int -> IntInf.int -> IntInf.int val shiftr : IntInf.int -> IntInf.int -> IntInf.int val test_bit : IntInf.int -> IntInf.int -> bool end = struct val maxWord = IntInf.pow (2, Word.wordSize); fun set_bit x n b = if n < maxWord then if b then IntInf.orb (x, IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n))) else IntInf.andb (x, IntInf.notb (IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n)))) else raise (Fail ("Bit index too large: " ^ IntInf.toString n)); fun shiftl x n = if n < maxWord then IntInf.<< (x, Word.fromLargeInt (IntInf.toLarge n)) else raise (Fail ("Shift operand too large: " ^ IntInf.toString n)); fun shiftr x n = if n < maxWord then IntInf.~>> (x, Word.fromLargeInt (IntInf.toLarge n)) else raise (Fail ("Shift operand too large: " ^ IntInf.toString n)); fun test_bit x n = if n < maxWord then IntInf.andb (x, IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n))) <> 0 else raise (Fail ("Bit index too large: " ^ IntInf.toString n)); end; (*struct Bits_Integer*)\ code_reserved SML Bits_Integer code_printing code_module Bits_Integer \ (OCaml) \module Bits_Integer : sig val shiftl : Z.t -> Z.t -> Z.t val shiftr : Z.t -> Z.t -> Z.t val test_bit : Z.t -> Z.t -> bool end = struct (* We do not need an explicit range checks here, because Big_int.int_of_big_int raises Failure if the argument does not fit into an int. *) let shiftl x n = Z.shift_left x (Z.to_int n);; let shiftr x n = Z.shift_right x (Z.to_int n);; let test_bit x n = Z.testbit x (Z.to_int n);; end;; (*struct Bits_Integer*)\ code_reserved OCaml Bits_Integer code_printing code_module Data_Bits \ (Haskell) \ module Data_Bits where { import qualified Data.Bits; {- The ...Bounded functions assume that the Integer argument for the shift or bit index fits into an Int, is non-negative and (for types of fixed bit width) less than bitSize -} infixl 7 .&.; infixl 6 `xor`; infixl 5 .|.; (.&.) :: Data.Bits.Bits a => a -> a -> a; (.&.) = (Data.Bits..&.); xor :: Data.Bits.Bits a => a -> a -> a; xor = Data.Bits.xor; (.|.) :: Data.Bits.Bits a => a -> a -> a; (.|.) = (Data.Bits..|.); complement :: Data.Bits.Bits a => a -> a; complement = Data.Bits.complement; testBitUnbounded :: Data.Bits.Bits a => a -> Integer -> Bool; testBitUnbounded x b | b <= toInteger (Prelude.maxBound :: Int) = Data.Bits.testBit x (fromInteger b) | otherwise = error ("Bit index too large: " ++ show b) ; testBitBounded :: Data.Bits.Bits a => a -> Integer -> Bool; testBitBounded x b = Data.Bits.testBit x (fromInteger b); setBitUnbounded :: Data.Bits.Bits a => a -> Integer -> Bool -> a; setBitUnbounded x n b | n <= toInteger (Prelude.maxBound :: Int) = if b then Data.Bits.setBit x (fromInteger n) else Data.Bits.clearBit x (fromInteger n) | otherwise = error ("Bit index too large: " ++ show n) ; setBitBounded :: Data.Bits.Bits a => a -> Integer -> Bool -> a; setBitBounded x n True = Data.Bits.setBit x (fromInteger n); setBitBounded x n False = Data.Bits.clearBit x (fromInteger n); shiftlUnbounded :: Data.Bits.Bits a => a -> Integer -> a; shiftlUnbounded x n | n <= toInteger (Prelude.maxBound :: Int) = Data.Bits.shiftL x (fromInteger n) | otherwise = error ("Shift operand too large: " ++ show n) ; shiftlBounded :: Data.Bits.Bits a => a -> Integer -> a; shiftlBounded x n = Data.Bits.shiftL x (fromInteger n); shiftrUnbounded :: Data.Bits.Bits a => a -> Integer -> a; shiftrUnbounded x n | n <= toInteger (Prelude.maxBound :: Int) = Data.Bits.shiftR x (fromInteger n) | otherwise = error ("Shift operand too large: " ++ show n) ; shiftrBounded :: (Ord a, Data.Bits.Bits a) => a -> Integer -> a; shiftrBounded x n = Data.Bits.shiftR x (fromInteger n); }\ and \ \@{theory HOL.Quickcheck_Narrowing} maps @{typ integer} to Haskell's Prelude.Int type instead of Integer. For compatibility with the Haskell target, we nevertheless provide bounded and unbounded functions.\ (Haskell_Quickcheck) \ module Data_Bits where { import qualified Data.Bits; {- The functions assume that the Int argument for the shift or bit index is non-negative and (for types of fixed bit width) less than bitSize -} infixl 7 .&.; infixl 6 `xor`; infixl 5 .|.; (.&.) :: Data.Bits.Bits a => a -> a -> a; (.&.) = (Data.Bits..&.); xor :: Data.Bits.Bits a => a -> a -> a; xor = Data.Bits.xor; (.|.) :: Data.Bits.Bits a => a -> a -> a; (.|.) = (Data.Bits..|.); complement :: Data.Bits.Bits a => a -> a; complement = Data.Bits.complement; testBitUnbounded :: Data.Bits.Bits a => a -> Prelude.Int -> Bool; testBitUnbounded = Data.Bits.testBit; testBitBounded :: Data.Bits.Bits a => a -> Prelude.Int -> Bool; testBitBounded = Data.Bits.testBit; setBitUnbounded :: Data.Bits.Bits a => a -> Prelude.Int -> Bool -> a; setBitUnbounded x n True = Data.Bits.setBit x n; setBitUnbounded x n False = Data.Bits.clearBit x n; setBitBounded :: Data.Bits.Bits a => a -> Prelude.Int -> Bool -> a; setBitBounded x n True = Data.Bits.setBit x n; setBitBounded x n False = Data.Bits.clearBit x n; shiftlUnbounded :: Data.Bits.Bits a => a -> Prelude.Int -> a; shiftlUnbounded = Data.Bits.shiftL; shiftlBounded :: Data.Bits.Bits a => a -> Prelude.Int -> a; shiftlBounded = Data.Bits.shiftL; shiftrUnbounded :: Data.Bits.Bits a => a -> Prelude.Int -> a; shiftrUnbounded = Data.Bits.shiftR; shiftrBounded :: (Ord a, Data.Bits.Bits a) => a -> Prelude.Int -> a; shiftrBounded = Data.Bits.shiftR; }\ code_reserved Haskell Data_Bits code_printing code_module Bits_Integer \ (Scala) \object Bits_Integer { def setBit(x: BigInt, n: BigInt, b: Boolean) : BigInt = if (n.isValidInt) if (b) x.setBit(n.toInt) else x.clearBit(n.toInt) else sys.error("Bit index too large: " + n.toString) def shiftl(x: BigInt, n: BigInt) : BigInt = if (n.isValidInt) x << n.toInt else sys.error("Shift index too large: " + n.toString) def shiftr(x: BigInt, n: BigInt) : BigInt = if (n.isValidInt) x << n.toInt else sys.error("Shift index too large: " + n.toString) def testBit(x: BigInt, n: BigInt) : Boolean = if (n.isValidInt) x.testBit(n.toInt) else sys.error("Bit index too large: " + n.toString) } /* object Bits_Integer */\ code_printing constant "(AND) :: integer \ integer \ integer" \ (SML) "IntInf.andb ((_),/ (_))" and (OCaml) "Z.logand" and (Haskell) "((Data'_Bits..&.) :: Integer -> Integer -> Integer)" and (Haskell_Quickcheck) "((Data'_Bits..&.) :: Prelude.Int -> Prelude.Int -> Prelude.Int)" and (Scala) infixl 3 "&" | constant "(OR) :: integer \ integer \ integer" \ (SML) "IntInf.orb ((_),/ (_))" and (OCaml) "Z.logor" and (Haskell) "((Data'_Bits..|.) :: Integer -> Integer -> Integer)" and (Haskell_Quickcheck) "((Data'_Bits..|.) :: Prelude.Int -> Prelude.Int -> Prelude.Int)" and (Scala) infixl 1 "|" | constant "(XOR) :: integer \ integer \ integer" \ (SML) "IntInf.xorb ((_),/ (_))" and (OCaml) "Z.logxor" and (Haskell) "(Data'_Bits.xor :: Integer -> Integer -> Integer)" and (Haskell_Quickcheck) "(Data'_Bits.xor :: Prelude.Int -> Prelude.Int -> Prelude.Int)" and (Scala) infixl 2 "^" | constant "NOT :: integer \ integer" \ (SML) "IntInf.notb" and (OCaml) "Z.lognot" and (Haskell) "(Data'_Bits.complement :: Integer -> Integer)" and (Haskell_Quickcheck) "(Data'_Bits.complement :: Prelude.Int -> Prelude.Int)" and (Scala) "_.unary'_~" code_printing constant bin_rest_integer \ (SML) "IntInf.div ((_), 2)" and (OCaml) "Z.shift'_right/ _/ 1" and (Haskell) "(Data'_Bits.shiftrUnbounded _ 1 :: Integer)" and (Haskell_Quickcheck) "(Data'_Bits.shiftrUnbounded _ 1 :: Prelude.Int)" and (Scala) "_ >> 1" context includes integer.lifting begin lemma bitNOT_integer_code [code]: fixes i :: integer shows "NOT i = - i - 1" -by transfer(simp add: int_not_def) + by transfer (simp add: not_int_def) lemma bin_rest_integer_code [code nbe]: "bin_rest_integer i = i div 2" by transfer rule lemma bin_last_integer_code [code]: "bin_last_integer i \ i AND 1 \ 0" - by transfer (rule bin_last_conv_AND) + by transfer (simp add: and_one_eq odd_iff_mod_2_eq_one) lemma bin_last_integer_nbe [code nbe]: "bin_last_integer i \ i mod 2 \ 0" -by transfer(simp add: bin_last_def) + by transfer (simp add: odd_iff_mod_2_eq_one) lemma bitval_bin_last_integer [code_unfold]: "of_bool (bin_last_integer i) = i AND 1" -by transfer(rule bitval_bin_last) + by transfer (simp add: and_one_eq mod_2_eq_odd) end definition integer_test_bit :: "integer \ integer \ bool" where "integer_test_bit x n = (if n < 0 then undefined x n else bit x (nat_of_integer n))" declare [[code drop: \bit :: integer \ nat \ bool\]] lemma bit_integer_code [code]: "bit x n \ integer_test_bit x (integer_of_nat n)" by (simp add: integer_test_bit_def) lemma integer_test_bit_code [code]: "integer_test_bit x (Code_Numeral.Neg n) = undefined x (Code_Numeral.Neg n)" "integer_test_bit 0 0 = False" "integer_test_bit 0 (Code_Numeral.Pos n) = False" "integer_test_bit (Code_Numeral.Pos num.One) 0 = True" "integer_test_bit (Code_Numeral.Pos (num.Bit0 n)) 0 = False" "integer_test_bit (Code_Numeral.Pos (num.Bit1 n)) 0 = True" "integer_test_bit (Code_Numeral.Pos num.One) (Code_Numeral.Pos n') = False" "integer_test_bit (Code_Numeral.Pos (num.Bit0 n)) (Code_Numeral.Pos n') = integer_test_bit (Code_Numeral.Pos n) (Code_Numeral.sub n' num.One)" "integer_test_bit (Code_Numeral.Pos (num.Bit1 n)) (Code_Numeral.Pos n') = integer_test_bit (Code_Numeral.Pos n) (Code_Numeral.sub n' num.One)" "integer_test_bit (Code_Numeral.Neg num.One) 0 = True" "integer_test_bit (Code_Numeral.Neg (num.Bit0 n)) 0 = False" "integer_test_bit (Code_Numeral.Neg (num.Bit1 n)) 0 = True" "integer_test_bit (Code_Numeral.Neg num.One) (Code_Numeral.Pos n') = True" "integer_test_bit (Code_Numeral.Neg (num.Bit0 n)) (Code_Numeral.Pos n') = integer_test_bit (Code_Numeral.Neg n) (Code_Numeral.sub n' num.One)" "integer_test_bit (Code_Numeral.Neg (num.Bit1 n)) (Code_Numeral.Pos n') = integer_test_bit (Code_Numeral.Neg (n + num.One)) (Code_Numeral.sub n' num.One)" - apply (simp_all add: integer_test_bit_def bit_integer_def) - using bin_nth_numeral_simps bit_numeral_int_simps(6) - by presburger + by (simp_all add: integer_test_bit_def bit_integer_def flip: bit_not_int_iff') code_printing constant integer_test_bit \ (SML) "Bits'_Integer.test'_bit" and (OCaml) "Bits'_Integer.test'_bit" and (Haskell) "(Data'_Bits.testBitUnbounded :: Integer -> Integer -> Bool)" and (Haskell_Quickcheck) "(Data'_Bits.testBitUnbounded :: Prelude.Int -> Prelude.Int -> Bool)" and (Scala) "Bits'_Integer.testBit" context includes integer.lifting begin lemma lsb_integer_code [code]: fixes x :: integer shows "lsb x = bit x 0" by transfer(simp add: lsb_int_def) definition integer_set_bit :: "integer \ integer \ bool \ integer" where [code del]: "integer_set_bit x n b = (if n < 0 then undefined x n b else set_bit x (nat_of_integer n) b)" lemma set_bit_integer_code [code]: "set_bit x i b = integer_set_bit x (integer_of_nat i) b" by(simp add: integer_set_bit_def) lemma set_bit_integer_conv_masks: fixes x :: integer shows "set_bit x i b = (if b then x OR (push_bit i 1) else x AND NOT (push_bit i 1))" by transfer (simp add: int_set_bit_False_conv_NAND int_set_bit_True_conv_OR) end code_printing constant integer_set_bit \ (SML) "Bits'_Integer.set'_bit" and (Haskell) "(Data'_Bits.setBitUnbounded :: Integer -> Integer -> Bool -> Integer)" and (Haskell_Quickcheck) "(Data'_Bits.setBitUnbounded :: Prelude.Int -> Prelude.Int -> Bool -> Prelude.Int)" and (Scala) "Bits'_Integer.setBit" text \ OCaml.Big\_int does not have a method for changing an individual bit, so we emulate that with masks. We prefer an Isabelle implementation, because this then takes care of the signs for AND and OR. \ lemma integer_set_bit_code [code]: "integer_set_bit x n b = (if n < 0 then undefined x n b else if b then x OR (push_bit (nat_of_integer n) 1) else x AND NOT (push_bit (nat_of_integer n) 1))" by (auto simp add: integer_set_bit_def not_less set_bit_eq set_bit_def unset_bit_def) definition integer_shiftl :: "integer \ integer \ integer" where [code del]: "integer_shiftl x n = (if n < 0 then undefined x n else push_bit (nat_of_integer n) x)" declare [[code drop: \push_bit :: nat \ integer \ integer\]] lemma shiftl_integer_code [code]: fixes x :: integer shows "push_bit n x = integer_shiftl x (integer_of_nat n)" by(auto simp add: integer_shiftl_def) context includes integer.lifting begin lemma shiftl_integer_conv_mult_pow2: fixes x :: integer shows "push_bit n x = x * 2 ^ n" by (fact push_bit_eq_mult) lemma integer_shiftl_code [code]: "integer_shiftl x (Code_Numeral.Neg n) = undefined x (Code_Numeral.Neg n)" "integer_shiftl x 0 = x" "integer_shiftl x (Code_Numeral.Pos n) = integer_shiftl (Code_Numeral.dup x) (Code_Numeral.sub n num.One)" "integer_shiftl 0 (Code_Numeral.Pos n) = 0" apply (simp_all add: integer_shiftl_def numeral_eq_Suc) apply transfer apply (simp add: ac_simps) done end code_printing constant integer_shiftl \ (SML) "Bits'_Integer.shiftl" and (OCaml) "Bits'_Integer.shiftl" and (Haskell) "(Data'_Bits.shiftlUnbounded :: Integer -> Integer -> Integer)" and (Haskell_Quickcheck) "(Data'_Bits.shiftlUnbounded :: Prelude.Int -> Prelude.Int -> Prelude.Int)" and (Scala) "Bits'_Integer.shiftl" definition integer_shiftr :: "integer \ integer \ integer" where [code del]: "integer_shiftr x n = (if n < 0 then undefined x n else drop_bit (nat_of_integer n) x)" declare [[code drop: \drop_bit :: nat \ integer \ integer\]] lemma shiftr_integer_conv_div_pow2: includes integer.lifting fixes x :: integer shows "drop_bit n x = x div 2 ^ n" by (fact drop_bit_eq_div) lemma shiftr_integer_code [code]: fixes x :: integer shows "drop_bit n x = integer_shiftr x (integer_of_nat n)" by(auto simp add: integer_shiftr_def) code_printing constant integer_shiftr \ (SML) "Bits'_Integer.shiftr" and (OCaml) "Bits'_Integer.shiftr" and (Haskell) "(Data'_Bits.shiftrUnbounded :: Integer -> Integer -> Integer)" and (Haskell_Quickcheck) "(Data'_Bits.shiftrUnbounded :: Prelude.Int -> Prelude.Int -> Prelude.Int)" and (Scala) "Bits'_Integer.shiftr" lemma integer_shiftr_code [code]: includes integer.lifting shows "integer_shiftr x (Code_Numeral.Neg n) = undefined x (Code_Numeral.Neg n)" "integer_shiftr x 0 = x" "integer_shiftr 0 (Code_Numeral.Pos n) = 0" "integer_shiftr (Code_Numeral.Pos num.One) (Code_Numeral.Pos n) = 0" "integer_shiftr (Code_Numeral.Pos (num.Bit0 n')) (Code_Numeral.Pos n) = integer_shiftr (Code_Numeral.Pos n') (Code_Numeral.sub n num.One)" "integer_shiftr (Code_Numeral.Pos (num.Bit1 n')) (Code_Numeral.Pos n) = integer_shiftr (Code_Numeral.Pos n') (Code_Numeral.sub n num.One)" "integer_shiftr (Code_Numeral.Neg num.One) (Code_Numeral.Pos n) = -1" "integer_shiftr (Code_Numeral.Neg (num.Bit0 n')) (Code_Numeral.Pos n) = integer_shiftr (Code_Numeral.Neg n') (Code_Numeral.sub n num.One)" "integer_shiftr (Code_Numeral.Neg (num.Bit1 n')) (Code_Numeral.Pos n) = integer_shiftr (Code_Numeral.Neg (Num.inc n')) (Code_Numeral.sub n num.One)" apply (simp_all add: integer_shiftr_def numeral_eq_Suc drop_bit_Suc) apply transfer apply simp apply transfer apply simp apply transfer apply (simp add: add_One) done context includes integer.lifting begin lemma Bit_integer_code [code]: "Bit_integer i False = push_bit 1 i" - "Bit_integer i True = (push_bit 1 i) + 1" - by (transfer; simp add: shiftl_int_def)+ + "Bit_integer i True = push_bit 1 i + 1" + by (transfer; simp)+ lemma msb_integer_code [code]: "msb (x :: integer) \ x < 0" -by transfer(simp add: msb_int_def) + by transfer (simp add: msb_int_def) end context includes integer.lifting natural.lifting begin lemma bitAND_integer_unfold [code]: "x AND y = (if x = 0 then 0 else if x = - 1 then y else Bit_integer (bin_rest_integer x AND bin_rest_integer y) (bin_last_integer x \ bin_last_integer y))" by transfer (auto simp add: algebra_simps and_int_rec [of _ \_ * 2\] and_int_rec [of \_ * 2\] and_int_rec [of \1 + _ * 2\] elim!: evenE oddE) lemma bitOR_integer_unfold [code]: "x OR y = (if x = 0 then y else if x = - 1 then - 1 else Bit_integer (bin_rest_integer x OR bin_rest_integer y) (bin_last_integer x \ bin_last_integer y))" by transfer (auto simp add: algebra_simps or_int_rec [of _ \_ * 2\] or_int_rec [of _ \1 + _ * 2\] or_int_rec [of \1 + _ * 2\] elim!: evenE oddE) lemma bitXOR_integer_unfold [code]: "x XOR y = (if x = 0 then y else if x = - 1 then NOT y else Bit_integer (bin_rest_integer x XOR bin_rest_integer y) (\ bin_last_integer x \ bin_last_integer y))" by transfer (auto simp add: algebra_simps xor_int_rec [of _ \_ * 2\] xor_int_rec [of \_ * 2\] xor_int_rec [of \1 + _ * 2\] elim!: evenE oddE) end section \Test code generator setup\ definition bit_integer_test :: "bool" where "bit_integer_test = (([ -1 AND 3, 1 AND -3, 3 AND 5, -3 AND (- 5) , -3 OR 1, 1 OR -3, 3 OR 5, -3 OR (- 5) , NOT 1, NOT (- 3) , -1 XOR 3, 1 XOR (- 3), 3 XOR 5, -5 XOR (- 3) , set_bit 5 4 True, set_bit (- 5) 2 True, set_bit 5 0 False, set_bit (- 5) 1 False , push_bit 2 1, push_bit 3 (- 1) , drop_bit 3 100, drop_bit 3 (- 100)] :: integer list) = [ 3, 1, 1, -7 , -3, -3, 7, -1 , -2, 2 , -4, -4, 6, 6 , 21, -1, 4, -7 , 4, -8 , 12, -13] \ [ bit (5 :: integer) 4, bit (5 :: integer) 2, bit (-5 :: integer) 4, bit (-5 :: integer) 2 , lsb (5 :: integer), lsb (4 :: integer), lsb (-1 :: integer), lsb (-2 :: integer), msb (5 :: integer), msb (0 :: integer), msb (-1 :: integer), msb (-2 :: integer)] = [ False, True, True, False, True, False, True, False, False, False, True, True])" export_code bit_integer_test checking SML Haskell? Haskell_Quickcheck? OCaml? Scala notepad begin have bit_integer_test by eval have bit_integer_test by normalization have bit_integer_test by code_simp end ML_val \val true = @{code bit_integer_test}\ lemma "x AND y = x OR (y :: integer)" quickcheck[random, expect=counterexample] quickcheck[exhaustive, expect=counterexample] oops lemma "(x :: integer) AND x = x OR x" quickcheck[narrowing, expect=no_counterexample] oops lemma "(f :: integer \ unit) = g" quickcheck[narrowing, size=3, expect=no_counterexample] by(simp add: fun_eq_iff) hide_const bit_integer_test hide_fact bit_integer_test_def end diff --git a/thys/Native_Word/Code_Symbolic_Bits_Int.thy b/thys/Native_Word/Code_Symbolic_Bits_Int.thy --- a/thys/Native_Word/Code_Symbolic_Bits_Int.thy +++ b/thys/Native_Word/Code_Symbolic_Bits_Int.thy @@ -1,119 +1,119 @@ (* Title: Code_Symbolic_Bits_Int.thy Author: Andreas Lochbihler, ETH Zurich *) chapter \Symbolic implementation of bit operations on int\ theory Code_Symbolic_Bits_Int imports + "Word_Lib.Least_significant_bit" "Word_Lib.Generic_set_bit" - "Word_Lib.Least_significant_bit" - "Word_Lib.Bits_Int" + "Word_Lib.Bit_Comprehension" begin section \Implementations of bit operations on \<^typ>\int\ operating on symbolic representation\ lemma test_bit_int_code [code]: "bit (0::int) n = False" "bit (Int.Neg num.One) n = True" "bit (Int.Pos num.One) 0 = True" "bit (Int.Pos (num.Bit0 m)) 0 = False" "bit (Int.Pos (num.Bit1 m)) 0 = True" "bit (Int.Neg (num.Bit0 m)) 0 = False" "bit (Int.Neg (num.Bit1 m)) 0 = True" "bit (Int.Pos num.One) (Suc n) = False" "bit (Int.Pos (num.Bit0 m)) (Suc n) = bit (Int.Pos m) n" "bit (Int.Pos (num.Bit1 m)) (Suc n) = bit (Int.Pos m) n" "bit (Int.Neg (num.Bit0 m)) (Suc n) = bit (Int.Neg m) n" "bit (Int.Neg (num.Bit1 m)) (Suc n) = bit (Int.Neg (Num.inc m)) n" by (simp_all add: Num.add_One bit_Suc) lemma int_not_code [code]: "NOT (0 :: int) = -1" "NOT (Int.Pos n) = Int.Neg (Num.inc n)" "NOT (Int.Neg n) = Num.sub n num.One" - by (simp_all add: Num.add_One int_not_def) + by (simp_all add: Num.add_One not_int_def) lemma int_and_code [code]: fixes i j :: int shows "0 AND j = 0" "i AND 0 = 0" "Int.Pos n AND Int.Pos m = (case and_num n m of None \ 0 | Some n' \ Int.Pos n')" "Int.Neg n AND Int.Neg m = NOT (Num.sub n num.One OR Num.sub m num.One)" "Int.Pos n AND Int.Neg num.One = Int.Pos n" "Int.Pos n AND Int.Neg (num.Bit0 m) = Num.sub (or_not_num_neg (Num.BitM m) n) num.One" "Int.Pos n AND Int.Neg (num.Bit1 m) = Num.sub (or_not_num_neg (num.Bit0 m) n) num.One" "Int.Neg num.One AND Int.Pos m = Int.Pos m" "Int.Neg (num.Bit0 n) AND Int.Pos m = Num.sub (or_not_num_neg (Num.BitM n) m) num.One" "Int.Neg (num.Bit1 n) AND Int.Pos m = Num.sub (or_not_num_neg (num.Bit0 n) m) num.One" by (simp_all add: and_num_eq_None_iff and_num_eq_Some_iff sub_one_eq_not_neg numeral_or_not_num_eq ac_simps split: option.split) lemma int_or_code [code]: fixes i j :: int shows "0 OR j = j" "i OR 0 = i" "Int.Pos n OR Int.Pos m = Int.Pos (or_num n m)" "Int.Neg n OR Int.Neg m = NOT (Num.sub n num.One AND Num.sub m num.One)" "Int.Pos n OR Int.Neg num.One = Int.Neg num.One" "Int.Pos n OR Int.Neg (num.Bit0 m) = (case and_not_num (Num.BitM m) n of None \ -1 | Some n' \ Int.Neg (Num.inc n'))" "Int.Pos n OR Int.Neg (num.Bit1 m) = (case and_not_num (num.Bit0 m) n of None \ -1 | Some n' \ Int.Neg (Num.inc n'))" "Int.Neg num.One OR Int.Pos m = Int.Neg num.One" "Int.Neg (num.Bit0 n) OR Int.Pos m = (case and_not_num (Num.BitM n) m of None \ -1 | Some n' \ Int.Neg (Num.inc n'))" "Int.Neg (num.Bit1 n) OR Int.Pos m = (case and_not_num (num.Bit0 n) m of None \ -1 | Some n' \ Int.Neg (Num.inc n'))" apply (simp_all add: and_not_num_eq_None_iff and_not_num_eq_Some_iff numeral_or_num_eq sub_one_eq_not_neg add_One ac_simps split: option.split) apply (simp_all add: or_eq_not_not_and minus_numeral_inc_eq) done lemma int_xor_code [code]: fixes i j :: int shows "0 XOR j = j" "i XOR 0 = i" "Int.Pos n XOR Int.Pos m = (case xor_num n m of None \ 0 | Some n' \ Int.Pos n')" "Int.Neg n XOR Int.Neg m = Num.sub n num.One XOR Num.sub m num.One" "Int.Neg n XOR Int.Pos m = NOT (Num.sub n num.One XOR Int.Pos m)" "Int.Pos n XOR Int.Neg m = NOT (Int.Pos n XOR Num.sub m num.One)" by (simp_all add: xor_num_eq_None_iff xor_num_eq_Some_iff sub_one_eq_not_neg split: option.split) lemma bin_rest_code: "i div 2 = drop_bit 1 i" for i :: int - by (simp add: shiftr_int_def) - + by (simp add: drop_bit_eq_div) + lemma set_bits_code [code]: "set_bits = Code.abort (STR ''set_bits is unsupported on type int'') (\_. set_bits :: _ \ int)" -by simp + by simp lemma fixes i :: int - shows int_set_bit_True_conv_OR [code]: "set_bit i n True = i OR push_bit n 1" - and int_set_bit_False_conv_NAND [code]: "set_bit i n False = i AND NOT (push_bit n 1)" - and int_set_bit_conv_ops: "set_bit i n b = (if b then i OR (push_bit n 1) else i AND NOT (push_bit n 1))" - by (simp_all add: set_bit_int_def bin_set_conv_OR bin_clr_conv_NAND Bit_Operations.set_bit_int_def unset_bit_int_def) + shows int_set_bit_True_conv_OR [code]: "Generic_set_bit.set_bit i n True = i OR push_bit n 1" + and int_set_bit_False_conv_NAND [code]: "Generic_set_bit.set_bit i n False = i AND NOT (push_bit n 1)" + and int_set_bit_conv_ops: "Generic_set_bit.set_bit i n b = (if b then i OR (push_bit n 1) else i AND NOT (push_bit n 1))" + by (simp_all add: bit_eq_iff) (auto simp add: bit_simps) declare [[code drop: \drop_bit :: nat \ int \ int\]] lemma drop_bit_int_code [code]: fixes i :: int shows "drop_bit 0 i = i" "drop_bit (Suc n) 0 = (0 :: int)" "drop_bit (Suc n) (Int.Pos num.One) = 0" "drop_bit (Suc n) (Int.Pos (num.Bit0 m)) = drop_bit n (Int.Pos m)" "drop_bit (Suc n) (Int.Pos (num.Bit1 m)) = drop_bit n (Int.Pos m)" "drop_bit (Suc n) (Int.Neg num.One) = - 1" "drop_bit (Suc n) (Int.Neg (num.Bit0 m)) = drop_bit n (Int.Neg m)" "drop_bit (Suc n) (Int.Neg (num.Bit1 m)) = drop_bit n (Int.Neg (Num.inc m))" by (simp_all add: drop_bit_Suc add_One) declare [[code drop: \push_bit :: nat \ int \ int\]] lemma push_bit_int_code [code]: "push_bit 0 i = i" "push_bit (Suc n) i = push_bit n (Int.dup i)" by (simp_all add: ac_simps) lemma int_lsb_code [code]: "lsb (0 :: int) = False" "lsb (Int.Pos num.One) = True" "lsb (Int.Pos (num.Bit0 w)) = False" "lsb (Int.Pos (num.Bit1 w)) = True" "lsb (Int.Neg num.One) = True" "lsb (Int.Neg (num.Bit0 w)) = False" "lsb (Int.Neg (num.Bit1 w)) = True" by simp_all end diff --git a/thys/Native_Word/Code_Target_Bits_Int.thy b/thys/Native_Word/Code_Target_Bits_Int.thy --- a/thys/Native_Word/Code_Target_Bits_Int.thy +++ b/thys/Native_Word/Code_Target_Bits_Int.thy @@ -1,92 +1,94 @@ (* Title: Code_Target_Bits_Int.thy Author: Andreas Lochbihler, ETH Zurich *) chapter \Implementation of bit operations on int by target language operations\ theory Code_Target_Bits_Int imports Bits_Integer "HOL-Library.Code_Target_Int" begin declare [[code drop: - "(AND) :: int \ _" "(OR) :: int \ _" "(XOR) :: int \ _" "(NOT) :: int \ _" + "(AND) :: int \ _" "(OR) :: int \ _" "(XOR) :: int \ _" "NOT :: int \ _" "lsb :: int \ _" "set_bit :: int \ _" "bit :: int \ _" "push_bit :: _ \ int \ _" "drop_bit :: _ \ int \ _" int_of_integer_symbolic ]] -declare bitval_bin_last [code_unfold] +lemma [code_unfold]: + \of_bool (odd i) = i AND 1\ for i :: int + by (simp add: and_one_eq mod2_eq_if) lemma [code_unfold]: \bit x n \ x AND (push_bit n 1) \ 0\ for x :: int by (fact bit_iff_and_push_bit_not_eq_0) context includes integer.lifting begin lemma bit_int_code [code]: "bit (int_of_integer x) n = bit x n" by transfer simp lemma and_int_code [code]: "int_of_integer i AND int_of_integer j = int_of_integer (i AND j)" by transfer simp lemma or_int_code [code]: "int_of_integer i OR int_of_integer j = int_of_integer (i OR j)" by transfer simp lemma xor_int_code [code]: "int_of_integer i XOR int_of_integer j = int_of_integer (i XOR j)" by transfer simp lemma not_int_code [code]: "NOT (int_of_integer i) = int_of_integer (NOT i)" by transfer simp lemma push_bit_int_code [code]: \push_bit n (int_of_integer x) = int_of_integer (push_bit n x)\ by transfer simp lemma drop_bit_int_code [code]: \drop_bit n (int_of_integer x) = int_of_integer (drop_bit n x)\ by transfer simp lemma take_bit_int_code [code]: \take_bit n (int_of_integer x) = int_of_integer (take_bit n x)\ by transfer simp lemma lsb_int_code [code]: "lsb (int_of_integer x) = lsb x" by transfer simp lemma set_bit_int_code [code]: "set_bit (int_of_integer x) n b = int_of_integer (set_bit x n b)" by transfer simp lemma int_of_integer_symbolic_code [code]: "int_of_integer_symbolic = int_of_integer" by (simp add: int_of_integer_symbolic_def) context begin qualified definition even :: \int \ bool\ where [code_abbrev]: \even = Parity.even\ end lemma [code]: \Code_Target_Bits_Int.even i \ i AND 1 = 0\ by (simp add: Code_Target_Bits_Int.even_def even_iff_mod_2_eq_zero and_one_eq) lemma bin_rest_code: "int_of_integer i div 2 = int_of_integer (bin_rest_integer i)" by transfer simp end end diff --git a/thys/Native_Word/Code_Target_Word_Base.thy b/thys/Native_Word/Code_Target_Word_Base.thy --- a/thys/Native_Word/Code_Target_Word_Base.thy +++ b/thys/Native_Word/Code_Target_Word_Base.thy @@ -1,395 +1,408 @@ (* Title: Code_Target_Word_Base.thy Author: Andreas Lochbihler, ETH Zurich *) chapter \Common base for target language implementations of word types\ theory Code_Target_Word_Base imports "HOL-Library.Word" "Word_Lib.Signed_Division_Word" Bits_Integer begin text \More lemmas\ lemma div_half_nat: fixes x y :: nat assumes "y \ 0" shows "(x div y, x mod y) = (let q = 2 * (x div 2 div y); r = x - q * y in if y \ r then (q + 1, r - y) else (q, r))" proof - let ?q = "2 * (x div 2 div y)" have q: "?q = x div y - x div y mod 2" by(metis div_mult2_eq mult.commute minus_mod_eq_mult_div [symmetric]) let ?r = "x - ?q * y" have r: "?r = x mod y + x div y mod 2 * y" by(simp add: q diff_mult_distrib minus_mod_eq_div_mult [symmetric])(metis diff_diff_cancel mod_less_eq_dividend mod_mult2_eq add.commute mult.commute) show ?thesis proof(cases "y \ x - ?q * y") case True with assms q have "x div y mod 2 \ 0" unfolding r by (metis Nat.add_0_right diff_0_eq_0 diff_Suc_1 le_div_geq mod2_gr_0 mod_div_trivial mult_0 neq0_conv numeral_1_eq_Suc_0 numerals(1)) hence "x div y = ?q + 1" unfolding q by simp moreover hence "x mod y = ?r - y" by simp(metis minus_div_mult_eq_mod [symmetric] diff_commute diff_diff_left mult_Suc) ultimately show ?thesis using True by(simp add: Let_def) next case False hence "x div y mod 2 = 0" unfolding r by(simp add: not_le)(metis Nat.add_0_right assms div_less div_mult_self2 mod_div_trivial mult.commute) hence "x div y = ?q" unfolding q by simp moreover hence "x mod y = ?r" by (metis minus_div_mult_eq_mod [symmetric]) ultimately show ?thesis using False by(simp add: Let_def) qed qed lemma div_half_word: fixes x y :: "'a :: len word" assumes "y \ 0" shows "(x div y, x mod y) = (let q = push_bit 1 (drop_bit 1 x div y); r = x - q * y in if y \ r then (q + 1, r - y) else (q, r))" proof - obtain n where n: "x = of_nat n" "n < 2 ^ LENGTH('a)" by (rule that [of \unat x\]) simp_all moreover obtain m where m: "y = of_nat m" "m < 2 ^ LENGTH('a)" by (rule that [of \unat y\]) simp_all ultimately have [simp]: \unat (of_nat n :: 'a word) = n\ \unat (of_nat m :: 'a word) = m\ by (transfer, simp add: take_bit_of_nat take_bit_nat_eq_self_iff)+ let ?q = "push_bit 1 (drop_bit 1 x div y)" let ?q' = "2 * (n div 2 div m)" have "n div 2 div m < 2 ^ LENGTH('a)" using n by (metis of_nat_inverse unat_lt2p uno_simps(2)) hence q: "?q = of_nat ?q'" using n m by (auto simp add: drop_bit_eq_div word_arith_nat_div uno_simps take_bit_nat_eq_self) from assms have "m \ 0" using m by -(rule notI, simp) from n have "2 * (n div 2 div m) < 2 ^ LENGTH('a)" by(metis mult.commute div_mult2_eq minus_mod_eq_mult_div [symmetric] less_imp_diff_less of_nat_inverse unat_lt2p uno_simps(2)) moreover have "2 * (n div 2 div m) * m < 2 ^ LENGTH('a)" using n unfolding div_mult2_eq[symmetric] by(subst (2) mult.commute)(simp add: minus_mod_eq_div_mult [symmetric] diff_mult_distrib minus_mod_eq_mult_div [symmetric] div_mult2_eq) moreover have "2 * (n div 2 div m) * m \ n" by (simp flip: div_mult2_eq ac_simps) ultimately have r: "x - ?q * y = of_nat (n - ?q' * m)" and "y \ x - ?q * y \ of_nat (n - ?q' * m) - y = of_nat (n - ?q' * m - m)" using n m unfolding q apply (simp_all add: of_nat_diff) apply (subst of_nat_diff) apply (simp_all add: word_le_nat_alt take_bit_nat_eq_self unat_sub_if' unat_word_ariths) done then show ?thesis using n m div_half_nat [OF \m \ 0\, of n] unfolding q by (simp add: word_le_nat_alt word_div_def word_mod_def Let_def take_bit_nat_eq_self flip: zdiv_int zmod_int split del: if_split split: if_split_asm) qed lemma word_test_bit_set_bits: "bit (BITS n. f n :: 'a :: len word) n \ n < LENGTH('a) \ f n" by (fact bit_set_bits_word_iff) lemma word_of_int_conv_set_bits: "word_of_int i = (BITS n. bit i n)" by (rule word_eqI) (auto simp add: word_test_bit_set_bits bit_simps) lemma word_and_mask_or_conv_and_mask: "bit n index \ (n AND mask index) OR (push_bit index 1) = n AND mask (index + 1)" for n :: \'a::len word\ by(rule word_eqI)(auto simp add: bit_simps) lemma uint_and_mask_or_full: fixes n :: "'a :: len word" assumes "bit n (LENGTH('a) - 1)" and "mask1 = mask (LENGTH('a) - 1)" and "mask2 = push_bit (LENGTH('a) - 1) 1" shows "uint (n AND mask1) OR mask2 = uint n" proof - have "mask2 = uint (push_bit (LENGTH('a) - 1) 1 :: 'a word)" using assms - by (simp add: uint_shiftl word_size bintrunc_shiftl) + by transfer (simp add: take_bit_push_bit) hence "uint (n AND mask1) OR mask2 = uint (n AND mask1 OR (push_bit (LENGTH('a) - 1) 1 :: 'a word))" by(simp add: uint_or) also have "\ = uint (n AND mask (LENGTH('a) - 1 + 1))" using assms by(simp only: word_and_mask_or_conv_and_mask) also have "\ = uint n" by simp finally show ?thesis . qed text \Division on @{typ "'a word"} is unsigned, but Scala and OCaml only have signed division and modulus.\ lemmas word_sdiv_def = sdiv_word_def lemmas word_smod_def = smod_word_def lemma [code]: "x sdiv y = (let x' = sint x; y' = sint y; negative = (x' < 0) \ (y' < 0); result = abs x' div abs y' in word_of_int (if negative then -result else result))" for x y :: \'a::len word\ by (simp add: sdiv_word_def signed_divide_int_def sgn_if Let_def not_less not_le) lemma [code]: "x smod y = (let x' = sint x; y' = sint y; negative = (x' < 0); result = abs x' mod abs y' in word_of_int (if negative then -result else result))" for x y :: \'a::len word\ proof - have *: \k mod l = k - k div l * l\ for k l :: int by (simp add: minus_div_mult_eq_mod) show ?thesis by (simp add: smod_word_def signed_modulo_int_def signed_divide_int_def * sgn_if Let_def) qed text \ This algorithm implements unsigned division in terms of signed division. Taken from Hacker's Delight. \ lemma divmod_via_sdivmod: fixes x y :: "'a :: len word" assumes "y \ 0" shows "(x div y, x mod y) = (if push_bit (LENGTH('a) - 1) 1 \ y then if x < y then (0, x) else (1, x - y) else let q = (push_bit 1 (drop_bit 1 x sdiv y)); r = x - q * y in if r \ y then (q + 1, r - y) else (q, r))" proof(cases "push_bit (LENGTH('a) - 1) 1 \ y") case True note y = this show ?thesis proof(cases "x < y") case True then have "x mod y = x" by transfer simp thus ?thesis using True y by(simp add: word_div_lt_eq_0) next case False obtain n where n: "y = of_nat n" "n < 2 ^ LENGTH('a)" by (rule that [of \unat y\]) simp_all have "unat x < 2 ^ LENGTH('a)" by(rule unat_lt2p) also have "\ = 2 * 2 ^ (LENGTH('a) - 1)" by(metis Suc_pred len_gt_0 power_Suc One_nat_def) also have "\ \ 2 * n" using y n by transfer (simp add: push_bit_of_1 take_bit_eq_mod) finally have div: "x div of_nat n = 1" using False n by (simp add: word_div_eq_1_iff take_bit_nat_eq_self) moreover have "x mod y = x - x div y * y" by (simp add: minus_div_mult_eq_mod) with div n have "x mod y = x - y" by simp ultimately show ?thesis using False y n by simp qed next case False note y = this obtain n where n: "x = of_nat n" "n < 2 ^ LENGTH('a)" by (rule that [of \unat x\]) simp_all hence "int n div 2 + 2 ^ (LENGTH('a) - Suc 0) < 2 ^ LENGTH('a)" by (cases \LENGTH('a)\) (auto dest: less_imp_of_nat_less [where ?'a = int]) with y n have "sint (drop_bit 1 x) = uint (drop_bit 1 x)" - by (simp add: sint_uint sbintrunc_mod2p drop_bit_eq_div take_bit_nat_eq_self uint_div_distrib) + by (cases \LENGTH('a)\) + (auto simp add: sint_uint drop_bit_eq_div take_bit_nat_eq_self uint_div_distrib signed_take_bit_int_eq_self_iff) moreover have "uint y + 2 ^ (LENGTH('a) - Suc 0) < 2 ^ LENGTH('a)" using y by (cases \LENGTH('a)\) (simp_all add: not_le push_bit_of_1 word_less_alt uint_power_lower) then have "sint y = uint y" - by (simp add: sint_uint sbintrunc_mod2p) + apply (cases \LENGTH('a)\) + apply (auto simp add: sint_uint signed_take_bit_int_eq_self_iff) + using uint_ge_0 [of y] + by linarith ultimately show ?thesis using y apply (subst div_half_word [OF assms]) apply (simp add: sdiv_word_def signed_divide_int_def flip: uint_div) done qed text \More implementations tailored towards target-language implementations\ context includes integer.lifting begin lift_definition word_of_integer :: "integer \ 'a :: len word" is word_of_int . lemma word_of_integer_code [code]: "word_of_integer n = word_of_int (int_of_integer n)" by(simp add: word_of_integer.rep_eq) end lemma word_of_int_code: "uint (word_of_int x :: 'a word) = x AND mask (LENGTH('a :: len))" by (simp add: take_bit_eq_mask) context fixes f :: "nat \ bool" begin definition set_bits_aux :: \'a word \ nat \ 'a :: len word\ where \set_bits_aux w n = push_bit n w OR take_bit n (set_bits f)\ lemma bit_set_bit_aux [bit_simps]: \bit (set_bits_aux w n) m \ m < LENGTH('a) \ (if m < n then f m else bit w (m - n))\ for w :: \'a::len word\ by (auto simp add: bit_simps set_bits_aux_def) lemma set_bits_aux_conv: \set_bits_aux w n = (push_bit n w) OR (set_bits f AND mask n)\ for w :: \'a::len word\ by (rule bit_word_eqI) (simp add: bit_simps) corollary set_bits_conv_set_bits_aux: \set_bits f = (set_bits_aux 0 (LENGTH('a)) :: 'a :: len word)\ by (simp add: set_bits_aux_conv) lemma set_bits_aux_0 [simp]: \set_bits_aux w 0 = w\ by (simp add: set_bits_aux_conv) lemma set_bits_aux_Suc [simp]: \set_bits_aux w (Suc n) = set_bits_aux (push_bit 1 w OR (if f n then 1 else 0)) n\ by (rule bit_word_eqI) (auto simp add: bit_simps not_less le_less_Suc_eq mult.commute [of _ 2]) lemma set_bits_aux_simps [code]: \set_bits_aux w 0 = w\ \set_bits_aux w (Suc n) = set_bits_aux (push_bit 1 w OR (if f n then 1 else 0)) n\ by simp_all end lemma word_of_int_via_signed: fixes mask assumes mask_def: "mask = Bit_Operations.mask (LENGTH('a))" and shift_def: "shift = push_bit LENGTH('a) 1" and index_def: "index = LENGTH('a) - 1" and overflow_def:"overflow = push_bit (LENGTH('a) - 1) 1" and least_def: "least = - overflow" shows "(word_of_int i :: 'a :: len word) = (let i' = i AND mask in if bit i' index then if i' - shift < least \ overflow \ i' - shift then arbitrary1 i' else word_of_int (i' - shift) else if i' < least \ overflow \ i' then arbitrary2 i' else word_of_int i')" proof - define i' where "i' = i AND mask" - have "shift = mask + 1" unfolding assms by(simp add: bin_mask_p1_conv_shift) - hence "i' < shift" by(simp add: mask_def i'_def int_and_le) + have "shift = mask + 1" unfolding assms + by (simp add: mask_eq_exp_minus_1 push_bit_of_1) + hence "i' < shift" + by (simp add: mask_def i'_def) show ?thesis proof(cases "bit i' index") case True then have unf: "i' = overflow OR i'" apply (simp add: assms i'_def push_bit_of_1 flip: take_bit_eq_mask) apply (rule bit_eqI) apply (auto simp add: bit_take_bit_iff bit_or_iff bit_exp_iff) done - have "overflow \ i'" by(subst unf)(rule le_int_or, simp add: bin_sign_and assms i'_def) + have \overflow \ overflow OR i'\ + by (simp add: i'_def mask_def or_greater_eq) + then have "overflow \ i'" + by (subst unf) hence "i' - shift < least \ False" unfolding assms by(cases "LENGTH('a)")(simp_all add: not_less push_bit_of_1) moreover have "overflow \ i' - shift \ False" using \i' < shift\ unfolding assms by(cases "LENGTH('a)")(auto simp add: not_le push_bit_of_1 elim: less_le_trans) moreover have "word_of_int (i' - shift) = (word_of_int i :: 'a word)" using \i' < shift\ by (simp add: i'_def shift_def mask_def push_bit_of_1 word_of_int_eq_iff flip: take_bit_eq_mask) ultimately show ?thesis using True by(simp add: Let_def i'_def) next case False - hence "i' = i AND Bit_Operations.mask (LENGTH('a) - 1)" unfolding assms i'_def - by(clarsimp simp add: i'_def bit_simps intro!: bin_eqI)(cases "LENGTH('a)", auto simp add: less_Suc_eq) - also have "\ \ Bit_Operations.mask (LENGTH('a) - 1)" by(rule int_and_le) simp - also have "\ < overflow" unfolding overflow_def - by(simp add: bin_mask_p1_conv_shift[symmetric]) + have "i' = i AND Bit_Operations.mask (LENGTH('a) - 1)" + apply (rule bit_eqI) + apply (use False in \auto simp add: bit_simps assms i'_def\) + apply (auto simp add: less_le) + done + also have "\ \ Bit_Operations.mask (LENGTH('a) - 1)" + using AND_upper2 mask_nonnegative_int by blast + also have "\ < overflow" + by (simp add: mask_int_def push_bit_of_1 overflow_def) also have "least \ 0" unfolding least_def overflow_def by simp have "0 \ i'" by (simp add: i'_def mask_def) hence "least \ i'" using \least \ 0\ by simp moreover have "word_of_int i' = (word_of_int i :: 'a word)" by (simp add: i'_def mask_def of_int_and_eq of_int_mask_eq) ultimately show ?thesis using False by(simp add: Let_def i'_def) qed qed text \Quickcheck conversion functions\ context includes state_combinator_syntax begin definition qc_random_cnv :: "(natural \ 'a::term_of) \ natural \ Random.seed \ ('a \ (unit \ Code_Evaluation.term)) \ Random.seed" where "qc_random_cnv a_of_natural i = Random.range (i + 1) \\ (\k. Pair ( let n = a_of_natural k in (n, \_. Code_Evaluation.term_of n)))" end definition qc_exhaustive_cnv :: "(natural \ 'a) \ ('a \ (bool \ term list) option) \ natural \ (bool \ term list) option" where "qc_exhaustive_cnv a_of_natural f d = Quickcheck_Exhaustive.exhaustive (%x. f (a_of_natural x)) d" definition qc_full_exhaustive_cnv :: "(natural \ ('a::term_of)) \ ('a \ (unit \ term) \ (bool \ term list) option) \ natural \ (bool \ term list) option" where "qc_full_exhaustive_cnv a_of_natural f d = Quickcheck_Exhaustive.full_exhaustive (%(x, xt). f (a_of_natural x, %_. Code_Evaluation.term_of (a_of_natural x))) d" declare [[quickcheck_narrowing_ghc_options = "-XTypeSynonymInstances"]] definition qc_narrowing_drawn_from :: "'a list \ integer \ _" where "qc_narrowing_drawn_from xs = foldr Quickcheck_Narrowing.sum (map Quickcheck_Narrowing.cons (butlast xs)) (Quickcheck_Narrowing.cons (last xs))" locale quickcheck_narrowing_samples = fixes a_of_integer :: "integer \ 'a \ 'a :: {partial_term_of, term_of}" and zero :: "'a" and tr :: "typerep" begin function narrowing_samples :: "integer \ 'a list" where "narrowing_samples i = (if i > 0 then let (a, a') = a_of_integer i in narrowing_samples (i - 1) @ [a, a'] else [zero])" by pat_completeness auto termination including integer.lifting proof(relation "measure nat_of_integer") fix i :: integer assume "0 < i" thus "(i - 1, i) \ measure nat_of_integer" by simp(transfer, simp) qed simp definition partial_term_of_sample :: "integer \ 'a" where "partial_term_of_sample i = (if i < 0 then undefined else if i = 0 then zero else if i mod 2 = 0 then snd (a_of_integer (i div 2)) else fst (a_of_integer (i div 2 + 1)))" lemma partial_term_of_code: "partial_term_of (ty :: 'a itself) (Quickcheck_Narrowing.Narrowing_variable p t) \ Code_Evaluation.Free (STR ''_'') tr" "partial_term_of (ty :: 'a itself) (Quickcheck_Narrowing.Narrowing_constructor i []) \ Code_Evaluation.term_of (partial_term_of_sample i)" by (rule partial_term_of_anything)+ end lemmas [code] = quickcheck_narrowing_samples.narrowing_samples.simps quickcheck_narrowing_samples.partial_term_of_sample_def text \ The separate code target \SML_word\ collects setups for the code generator that PolyML does not provide. \ setup \Code_Target.add_derived_target ("SML_word", [(Code_ML.target_SML, I)])\ code_identifier code_module Code_Target_Word_Base \ (SML) Word and (Haskell) Word and (OCaml) Word and (Scala) Word end diff --git a/thys/Word_Lib/Bit_Comprehension.thy b/thys/Word_Lib/Bit_Comprehension.thy --- a/thys/Word_Lib/Bit_Comprehension.thy +++ b/thys/Word_Lib/Bit_Comprehension.thy @@ -1,250 +1,251 @@ (* * Copyright Brian Huffman, PSU; Jeremy Dawson and Gerwin Klein, NICTA * * SPDX-License-Identifier: BSD-2-Clause *) section \Comprehension syntax for bit expressions\ theory Bit_Comprehension - imports "HOL-Library.Word" + imports + "HOL-Library.Word" begin class bit_comprehension = ring_bit_operations + fixes set_bits :: \(nat \ bool) \ 'a\ (binder \BITS \ 10) assumes set_bits_bit_eq: \set_bits (bit a) = a\ begin lemma set_bits_False_eq [simp]: \(BITS _. False) = 0\ using set_bits_bit_eq [of 0] by (simp add: bot_fun_def) end instantiation int :: bit_comprehension begin definition \set_bits f = ( if \n. \m\n. f m = f n then let n = LEAST n. \m\n. f m = f n in signed_take_bit n (horner_sum of_bool 2 (map f [0.. instance proof fix k :: int from int_bit_bound [of k] obtain n where *: \\m. n \ m \ bit k m \ bit k n\ and **: \n > 0 \ bit k (n - 1) \ bit k n\ by blast then have ***: \\n. \n'\n. bit k n' \ bit k n\ by meson have l: \(LEAST q. \m\q. bit k m \ bit k q) = n\ apply (rule Least_equality) using * apply blast apply (metis "**" One_nat_def Suc_pred le_cases le0 neq0_conv not_less_eq_eq) done show \set_bits (bit k) = k\ apply (simp only: *** set_bits_int_def horner_sum_bit_eq_take_bit l) apply simp apply (rule bit_eqI) apply (simp add: bit_signed_take_bit_iff min_def) apply (auto simp add: not_le bit_take_bit_iff dest: *) done qed end lemma int_set_bits_K_False [simp]: "(BITS _. False) = (0 :: int)" by (simp add: set_bits_int_def) lemma int_set_bits_K_True [simp]: "(BITS _. True) = (-1 :: int)" by (simp add: set_bits_int_def) instantiation word :: (len) bit_comprehension begin definition word_set_bits_def: \(BITS n. P n) = (horner_sum of_bool 2 (map P [0.. instance by standard (simp add: word_set_bits_def horner_sum_bit_eq_take_bit) end lemma bit_set_bits_word_iff [bit_simps]: \bit (set_bits P :: 'a::len word) n \ n < LENGTH('a) \ P n\ by (auto simp add: word_set_bits_def bit_horner_sum_bit_word_iff) lemma set_bits_K_False [simp]: \set_bits (\_. False) = (0 :: 'a :: len word)\ by (rule bit_word_eqI) (simp add: bit_set_bits_word_iff) lemma set_bits_int_unfold': \set_bits f = (if \n. \n'\n. \ f n' then let n = LEAST n. \n'\n. \ f n' in horner_sum of_bool 2 (map f [0..n. \n'\n. f n' then let n = LEAST n. \n'\n. f n' in signed_take_bit n (horner_sum of_bool 2 (map f [0.. proof (cases \\n. \m\n. f m \ f n\) case True then obtain q where q: \\m\q. f m \ f q\ by blast define n where \n = (LEAST n. \m\n. f m \ f n)\ have \\m\n. f m \ f n\ unfolding n_def using q by (rule LeastI [of _ q]) then have n: \\m. n \ m \ f m \ f n\ by blast from n_def have n_eq: \(LEAST q. \m\q. f m \ f n) = n\ by (smt Least_equality Least_le \\m\n. f m = f n\ dual_order.refl le_refl n order_refl) show ?thesis proof (cases \f n\) case False with n have *: \\n. \n'\n. \ f n'\ by blast have **: \(LEAST n. \n'\n. \ f n') = n\ using False n_eq by simp from * False show ?thesis apply (simp add: set_bits_int_def n_def [symmetric] ** del: upt.upt_Suc) apply (auto simp add: take_bit_horner_sum_bit_eq bit_horner_sum_bit_iff take_map signed_take_bit_def set_bits_int_def horner_sum_bit_eq_take_bit simp del: upt.upt_Suc) done next case True with n have *: \\n. \n'\n. f n'\ by blast have ***: \\ (\n. \n'\n. \ f n')\ apply (rule ccontr) using * nat_le_linear by auto have **: \(LEAST n. \n'\n. f n') = n\ using True n_eq by simp from * *** True show ?thesis apply (simp add: set_bits_int_def n_def [symmetric] ** del: upt.upt_Suc) apply (auto simp add: take_bit_horner_sum_bit_eq bit_horner_sum_bit_iff take_map signed_take_bit_def set_bits_int_def horner_sum_bit_eq_take_bit nth_append simp del: upt.upt_Suc) done qed next case False then show ?thesis by (auto simp add: set_bits_int_def) qed inductive wf_set_bits_int :: "(nat \ bool) \ bool" for f :: "nat \ bool" where zeros: "\n' \ n. \ f n' \ wf_set_bits_int f" | ones: "\n' \ n. f n' \ wf_set_bits_int f" lemma wf_set_bits_int_simps: "wf_set_bits_int f \ (\n. (\n'\n. \ f n') \ (\n'\n. f n'))" by(auto simp add: wf_set_bits_int.simps) lemma wf_set_bits_int_const [simp]: "wf_set_bits_int (\_. b)" by(cases b)(auto intro: wf_set_bits_int.intros) lemma wf_set_bits_int_fun_upd [simp]: "wf_set_bits_int (f(n := b)) \ wf_set_bits_int f" (is "?lhs \ ?rhs") proof assume ?lhs then obtain n' where "(\n''\n'. \ (f(n := b)) n'') \ (\n''\n'. (f(n := b)) n'')" by(auto simp add: wf_set_bits_int_simps) hence "(\n''\max (Suc n) n'. \ f n'') \ (\n''\max (Suc n) n'. f n'')" by auto thus ?rhs by(auto simp only: wf_set_bits_int_simps) next assume ?rhs then obtain n' where "(\n''\n'. \ f n'') \ (\n''\n'. f n'')" (is "?wf f n'") by(auto simp add: wf_set_bits_int_simps) hence "?wf (f(n := b)) (max (Suc n) n')" by auto thus ?lhs by(auto simp only: wf_set_bits_int_simps) qed lemma wf_set_bits_int_Suc [simp]: "wf_set_bits_int (\n. f (Suc n)) \ wf_set_bits_int f" (is "?lhs \ ?rhs") by(auto simp add: wf_set_bits_int_simps intro: le_SucI dest: Suc_le_D) context fixes f assumes wff: "wf_set_bits_int f" begin lemma int_set_bits_unfold_BIT: "set_bits f = of_bool (f 0) + (2 :: int) * set_bits (f \ Suc)" using wff proof cases case (zeros n) show ?thesis proof(cases "\n. \ f n") case True hence "f = (\_. False)" by auto thus ?thesis using True by(simp add: o_def) next case False then obtain n' where "f n'" by blast with zeros have "(LEAST n. \n'\n. \ f n') = Suc (LEAST n. \n'\Suc n. \ f n')" by(auto intro: Least_Suc) also have "(\n. \n'\Suc n. \ f n') = (\n. \n'\n. \ f (Suc n'))" by(auto dest: Suc_le_D) also from zeros have "\n'\n. \ f (Suc n')" by auto ultimately show ?thesis using zeros apply (simp (no_asm_simp) add: set_bits_int_unfold' exI del: upt.upt_Suc flip: map_map split del: if_split) apply (simp only: map_Suc_upt upt_conv_Cons) apply simp done qed next case (ones n) show ?thesis proof(cases "\n. f n") case True hence "f = (\_. True)" by auto thus ?thesis using True by(simp add: o_def) next case False then obtain n' where "\ f n'" by blast with ones have "(LEAST n. \n'\n. f n') = Suc (LEAST n. \n'\Suc n. f n')" by(auto intro: Least_Suc) also have "(\n. \n'\Suc n. f n') = (\n. \n'\n. f (Suc n'))" by(auto dest: Suc_le_D) also from ones have "\n'\n. f (Suc n')" by auto moreover from ones have "(\n. \n'\n. \ f n') = False" by(auto intro!: exI[where x="max n m" for n m] simp add: max_def split: if_split_asm) moreover hence "(\n. \n'\n. \ f (Suc n')) = False" by(auto elim: allE[where x="Suc n" for n] dest: Suc_le_D) ultimately show ?thesis using ones apply (simp (no_asm_simp) add: set_bits_int_unfold' exI split del: if_split) apply (auto simp add: Let_def hd_map map_tl[symmetric] map_map[symmetric] map_Suc_upt upt_conv_Cons signed_take_bit_Suc not_le simp del: map_map) done qed qed lemma bin_last_set_bits [simp]: "odd (set_bits f :: int) = f 0" by (subst int_set_bits_unfold_BIT) simp_all lemma bin_rest_set_bits [simp]: "set_bits f div (2 :: int) = set_bits (f \ Suc)" by (subst int_set_bits_unfold_BIT) simp_all lemma bin_nth_set_bits [simp]: "bit (set_bits f :: int) m \ f m" using wff proof (induction m arbitrary: f) case 0 then show ?case by (simp add: Bit_Comprehension.bin_last_set_bits) next case Suc from Suc.IH [of "f \ Suc"] Suc.prems show ?case by (simp add: Bit_Comprehension.bin_rest_set_bits comp_def bit_Suc) qed end end diff --git a/thys/Word_Lib/Bits_Int.thy b/thys/Word_Lib/Bits_Int.thy --- a/thys/Word_Lib/Bits_Int.thy +++ b/thys/Word_Lib/Bits_Int.thy @@ -1,1568 +1,1561 @@ (* * Copyright Brian Huffman, PSU; Jeremy Dawson and Gerwin Klein, NICTA * * SPDX-License-Identifier: BSD-2-Clause *) section \Bitwise Operations on integers\ theory Bits_Int - imports "HOL-Library.Word" "Word_Lib.Most_significant_bit" "Word_Lib.Generic_set_bit" + imports + "Word_Lib.Most_significant_bit" + "Word_Lib.Least_significant_bit" + "Word_Lib.Generic_set_bit" + "Word_Lib.Bit_Comprehension" begin subsection \Implicit bit representation of \<^typ>\int\\ lemma bin_last_def: "(odd :: int \ bool) w \ w mod 2 = 1" by (fact odd_iff_mod_2_eq_one) lemma bin_last_numeral_simps [simp]: "\ odd (0 :: int)" "odd (1 :: int)" "odd (- 1 :: int)" "odd (Numeral1 :: int)" "\ odd (numeral (Num.Bit0 w) :: int)" "odd (numeral (Num.Bit1 w) :: int)" "\ odd (- numeral (Num.Bit0 w) :: int)" "odd (- numeral (Num.Bit1 w) :: int)" by simp_all lemma bin_rest_numeral_simps [simp]: "(\k::int. k div 2) 0 = 0" "(\k::int. k div 2) 1 = 0" "(\k::int. k div 2) (- 1) = - 1" "(\k::int. k div 2) Numeral1 = 0" "(\k::int. k div 2) (numeral (Num.Bit0 w)) = numeral w" "(\k::int. k div 2) (numeral (Num.Bit1 w)) = numeral w" "(\k::int. k div 2) (- numeral (Num.Bit0 w)) = - numeral w" "(\k::int. k div 2) (- numeral (Num.Bit1 w)) = - numeral (w + Num.One)" by simp_all lemma bin_rl_eqI: "\(\k::int. k div 2) x = (\k::int. k div 2) y; odd x = odd y\ \ x = y" by (auto elim: oddE) lemma [simp]: shows bin_rest_lt0: "(\k::int. k div 2) i < 0 \ i < 0" and bin_rest_ge_0: "(\k::int. k div 2) i \ 0 \ i \ 0" by auto lemma bin_rest_gt_0 [simp]: "(\k::int. k div 2) x > 0 \ x > 1" by auto subsection \Bit projection\ lemma bin_nth_eq_iff: "(bit :: int \ nat \ bool) x = (bit :: int \ nat \ bool) y \ x = y" by (simp add: bit_eq_iff fun_eq_iff) lemma bin_eqI: "x = y" if "\n. (bit :: int \ nat \ bool) x n \ (bit :: int \ nat \ bool) y n" using that by (rule bit_eqI) lemma bin_eq_iff: "x = y \ (\n. (bit :: int \ nat \ bool) x n = (bit :: int \ nat \ bool) y n)" by (fact bit_eq_iff) lemma bin_nth_zero [simp]: "\ (bit :: int \ nat \ bool) 0 n" by simp lemma bin_nth_1 [simp]: "(bit :: int \ nat \ bool) 1 n \ n = 0" by (cases n) (simp_all add: bit_Suc) lemma bin_nth_minus1 [simp]: "(bit :: int \ nat \ bool) (- 1) n" by simp lemma bin_nth_numeral: "(\k::int. k div 2) x = y \ (bit :: int \ nat \ bool) x (numeral n) = (bit :: int \ nat \ bool) y (pred_numeral n)" by (simp add: numeral_eq_Suc bit_Suc) lemmas bin_nth_numeral_simps [simp] = bin_nth_numeral [OF bin_rest_numeral_simps(8)] lemmas bin_nth_simps = bit_0 bit_Suc bin_nth_zero bin_nth_minus1 bin_nth_numeral_simps lemma nth_2p_bin: "(bit :: int \ nat \ bool) (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: "(bit :: int \ nat \ bool) (((\k::int. k div 2) ^^ k) w) n = (bit :: int \ nat \ bool) w (n + k)" apply (induct k arbitrary: n) apply clarsimp apply clarsimp apply (simp only: bit_Suc [symmetric] add_Suc) done lemma bin_nth_numeral_unfold: "(bit :: int \ nat \ bool) (numeral (num.Bit0 x)) n \ n > 0 \ (bit :: int \ nat \ bool) (numeral x) (n - 1)" "(bit :: int \ nat \ bool) (numeral (num.Bit1 x)) n \ (n > 0 \ (bit :: int \ nat \ bool) (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" by (simp_all add: bin_sign_def) lemma bin_sign_rest [simp]: "bin_sign ((\k::int. k div 2) w) = bin_sign w" by (simp add: bin_sign_def) lemma bintrunc_mod2p: "(take_bit :: nat \ int \ int) n w = w mod 2 ^ n" by (fact take_bit_eq_mod) lemma sbintrunc_mod2p: "(signed_take_bit :: nat \ int \ int) n w = (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n" by (simp add: bintrunc_mod2p signed_take_bit_eq_take_bit_shift) lemma sbintrunc_eq_take_bit: \(signed_take_bit :: nat \ int \ int) n k = take_bit (Suc n) (k + 2 ^ n) - 2 ^ n\ by (fact signed_take_bit_eq_take_bit_shift) lemma sign_bintr: "bin_sign ((take_bit :: nat \ int \ int) n w) = 0" by (simp add: bin_sign_def) lemma bintrunc_n_0: "(take_bit :: nat \ int \ int) n 0 = 0" by (fact take_bit_of_0) lemma sbintrunc_n_0: "(signed_take_bit :: nat \ int \ int) n 0 = 0" by (fact signed_take_bit_of_0) lemma sbintrunc_n_minus1: "(signed_take_bit :: nat \ int \ int) n (- 1) = -1" by (fact signed_take_bit_of_minus_1) lemma bintrunc_Suc_numeral: "(take_bit :: nat \ int \ int) (Suc n) 1 = 1" "(take_bit :: nat \ int \ int) (Suc n) (- 1) = 1 + 2 * (take_bit :: nat \ int \ int) n (- 1)" "(take_bit :: nat \ int \ int) (Suc n) (numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \ int \ int) n (numeral w)" "(take_bit :: nat \ int \ int) (Suc n) (numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \ int \ int) n (numeral w)" "(take_bit :: nat \ int \ int) (Suc n) (- numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \ int \ int) n (- numeral w)" "(take_bit :: nat \ int \ int) (Suc n) (- numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \ int \ int) n (- numeral (w + Num.One))" by (simp_all add: take_bit_Suc) lemma sbintrunc_0_numeral [simp]: "(signed_take_bit :: nat \ int \ int) 0 1 = -1" "(signed_take_bit :: nat \ int \ int) 0 (numeral (Num.Bit0 w)) = 0" "(signed_take_bit :: nat \ int \ int) 0 (numeral (Num.Bit1 w)) = -1" "(signed_take_bit :: nat \ int \ int) 0 (- numeral (Num.Bit0 w)) = 0" "(signed_take_bit :: nat \ int \ int) 0 (- numeral (Num.Bit1 w)) = -1" by simp_all lemma sbintrunc_Suc_numeral: "(signed_take_bit :: nat \ int \ int) (Suc n) 1 = 1" "(signed_take_bit :: nat \ int \ int) (Suc n) (numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \ int \ int) n (numeral w)" "(signed_take_bit :: nat \ int \ int) (Suc n) (numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \ int \ int) n (numeral w)" "(signed_take_bit :: nat \ int \ int) (Suc n) (- numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \ int \ int) n (- numeral w)" "(signed_take_bit :: nat \ int \ int) (Suc n) (- numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \ int \ int) n (- numeral (w + Num.One))" by (simp_all add: signed_take_bit_Suc) lemma bin_sign_lem: "(bin_sign ((signed_take_bit :: nat \ int \ int) n bin) = -1) = bit bin n" by (simp add: bin_sign_def) lemma nth_bintr: "(bit :: int \ nat \ bool) ((take_bit :: nat \ int \ int) m w) n \ n < m \ (bit :: int \ nat \ bool) w n" by (fact bit_take_bit_iff) lemma nth_sbintr: "(bit :: int \ nat \ bool) ((signed_take_bit :: nat \ int \ int) m w) n = (if n < m then (bit :: int \ nat \ bool) w n else (bit :: int \ nat \ bool) w m)" by (simp add: bit_signed_take_bit_iff min_def) lemma bin_nth_Bit0: "(bit :: int \ nat \ bool) (numeral (Num.Bit0 w)) n \ (\m. n = Suc m \ (bit :: int \ nat \ bool) (numeral w) m)" using bit_double_iff [of \numeral w :: int\ n] by (auto intro: exI [of _ \n - 1\]) lemma bin_nth_Bit1: "(bit :: int \ nat \ bool) (numeral (Num.Bit1 w)) n \ n = 0 \ (\m. n = Suc m \ (bit :: int \ nat \ bool) (numeral w) m)" using even_bit_succ_iff [of \2 * numeral w :: int\ n] bit_double_iff [of \numeral w :: int\ n] by auto lemma bintrunc_bintrunc_l: "n \ m \ (take_bit :: nat \ int \ int) m ((take_bit :: nat \ int \ int) n w) = (take_bit :: nat \ int \ int) n w" by (simp add: min.absorb2) lemma sbintrunc_sbintrunc_l: "n \ m \ (signed_take_bit :: nat \ int \ int) m ((signed_take_bit :: nat \ int \ int) n w) = (signed_take_bit :: nat \ int \ int) n w" by (simp add: min.absorb2) lemma bintrunc_bintrunc_ge: "n \ m \ (take_bit :: nat \ int \ int) n ((take_bit :: nat \ int \ int) m w) = (take_bit :: nat \ int \ int) n w" by (rule bin_eqI) (auto simp: nth_bintr) lemma bintrunc_bintrunc_min [simp]: "(take_bit :: nat \ int \ int) m ((take_bit :: nat \ int \ int) n w) = (take_bit :: nat \ int \ int) (min m n) w" by (rule take_bit_take_bit) lemma sbintrunc_sbintrunc_min [simp]: "(signed_take_bit :: nat \ int \ int) m ((signed_take_bit :: nat \ int \ int) n w) = (signed_take_bit :: nat \ int \ int) (min m n) w" by (rule signed_take_bit_signed_take_bit) lemmas sbintrunc_Suc_Pls = signed_take_bit_Suc [where a="0::int", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Suc_Min = signed_take_bit_Suc [where a="-1::int", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Sucs = sbintrunc_Suc_Pls sbintrunc_Suc_Min sbintrunc_Suc_numeral lemmas sbintrunc_Pls = signed_take_bit_0 [where a="0::int", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_Min = signed_take_bit_0 [where a="-1::int", simplified bin_last_numeral_simps bin_rest_numeral_simps] lemmas sbintrunc_0_simps = sbintrunc_Pls sbintrunc_Min lemmas sbintrunc_simps = sbintrunc_0_simps sbintrunc_Sucs lemma bintrunc_minus: "0 < n \ (take_bit :: nat \ int \ int) (Suc (n - 1)) w = (take_bit :: nat \ int \ int) n w" by auto lemma sbintrunc_minus: "0 < n \ (signed_take_bit :: nat \ int \ int) (Suc (n - 1)) w = (signed_take_bit :: nat \ int \ int) n w" by auto lemmas sbintrunc_minus_simps = sbintrunc_Sucs [THEN [2] sbintrunc_minus [symmetric, THEN trans]] lemma sbintrunc_BIT_I: \0 < n \ (signed_take_bit :: nat \ int \ int) (n - 1) 0 = y \ (signed_take_bit :: nat \ int \ int) n 0 = 2 * y\ by simp lemma sbintrunc_Suc_Is: \(signed_take_bit :: nat \ int \ int) n (- 1) = y \ (signed_take_bit :: nat \ int \ int) (Suc n) (- 1) = 1 + 2 * y\ by auto lemma sbintrunc_Suc_lem: "(signed_take_bit :: nat \ int \ int) (Suc n) x = y \ m = Suc n \ (signed_take_bit :: nat \ int \ int) m x = y" by (rule ssubst) lemmas sbintrunc_Suc_Ialts = sbintrunc_Suc_Is [THEN sbintrunc_Suc_lem] lemma sbintrunc_bintrunc_lt: "m > n \ (signed_take_bit :: nat \ int \ int) n ((take_bit :: nat \ int \ int) m w) = (signed_take_bit :: nat \ int \ int) n w" by (rule bin_eqI) (auto simp: nth_sbintr nth_bintr) lemma bintrunc_sbintrunc_le: "m \ Suc n \ (take_bit :: nat \ int \ int) m ((signed_take_bit :: nat \ int \ int) n w) = (take_bit :: nat \ int \ int) m w" by (rule take_bit_signed_take_bit) lemmas bintrunc_sbintrunc [simp] = order_refl [THEN bintrunc_sbintrunc_le] lemmas sbintrunc_bintrunc [simp] = lessI [THEN sbintrunc_bintrunc_lt] lemmas bintrunc_bintrunc [simp] = order_refl [THEN bintrunc_bintrunc_l] lemmas sbintrunc_sbintrunc [simp] = order_refl [THEN sbintrunc_sbintrunc_l] lemma bintrunc_sbintrunc' [simp]: "0 < n \ (take_bit :: nat \ int \ int) n ((signed_take_bit :: nat \ int \ int) (n - 1) w) = (take_bit :: nat \ int \ int) n w" by (cases n) simp_all lemma sbintrunc_bintrunc' [simp]: "0 < n \ (signed_take_bit :: nat \ int \ int) (n - 1) ((take_bit :: nat \ int \ int) n w) = (signed_take_bit :: nat \ int \ int) (n - 1) w" by (cases n) simp_all lemma bin_sbin_eq_iff: "(take_bit :: nat \ int \ int) (Suc n) x = (take_bit :: nat \ int \ int) (Suc n) y \ (signed_take_bit :: nat \ int \ int) n x = (signed_take_bit :: nat \ int \ int) n y" apply (rule iffI) apply (rule box_equals [OF _ sbintrunc_bintrunc sbintrunc_bintrunc]) apply simp apply (rule box_equals [OF _ bintrunc_sbintrunc bintrunc_sbintrunc]) apply simp done lemma bin_sbin_eq_iff': "0 < n \ (take_bit :: nat \ int \ int) n x = (take_bit :: nat \ int \ int) n y \ (signed_take_bit :: nat \ int \ int) (n - 1) x = (signed_take_bit :: nat \ int \ int) (n - 1) y" by (cases n) (simp_all add: bin_sbin_eq_iff) lemmas bintrunc_sbintruncS0 [simp] = bintrunc_sbintrunc' [unfolded One_nat_def] lemmas sbintrunc_bintruncS0 [simp] = sbintrunc_bintrunc' [unfolded One_nat_def] lemmas bintrunc_bintrunc_l' = le_add1 [THEN bintrunc_bintrunc_l] lemmas sbintrunc_sbintrunc_l' = le_add1 [THEN sbintrunc_sbintrunc_l] (* although bintrunc_minus_simps, if added to default simpset, tends to get applied where it's not wanted in developing the theories, we get a version for when the word length is given literally *) lemmas nat_non0_gr = trans [OF iszero_def [THEN Not_eq_iff [THEN iffD2]] refl] lemma bintrunc_numeral: "(take_bit :: nat \ int \ int) (numeral k) x = of_bool (odd x) + 2 * (take_bit :: nat \ int \ int) (pred_numeral k) (x div 2)" by (simp add: numeral_eq_Suc take_bit_Suc mod_2_eq_odd) lemma sbintrunc_numeral: "(signed_take_bit :: nat \ int \ int) (numeral k) x = of_bool (odd x) + 2 * (signed_take_bit :: nat \ int \ int) (pred_numeral k) (x div 2)" by (simp add: numeral_eq_Suc signed_take_bit_Suc mod2_eq_if) lemma bintrunc_numeral_simps [simp]: "(take_bit :: nat \ int \ int) (numeral k) (numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \ int \ int) (pred_numeral k) (numeral w)" "(take_bit :: nat \ int \ int) (numeral k) (numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \ int \ int) (pred_numeral k) (numeral w)" "(take_bit :: nat \ int \ int) (numeral k) (- numeral (Num.Bit0 w)) = 2 * (take_bit :: nat \ int \ int) (pred_numeral k) (- numeral w)" "(take_bit :: nat \ int \ int) (numeral k) (- numeral (Num.Bit1 w)) = 1 + 2 * (take_bit :: nat \ int \ int) (pred_numeral k) (- numeral (w + Num.One))" "(take_bit :: nat \ int \ int) (numeral k) 1 = 1" by (simp_all add: bintrunc_numeral) lemma sbintrunc_numeral_simps [simp]: "(signed_take_bit :: nat \ int \ int) (numeral k) (numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \ int \ int) (pred_numeral k) (numeral w)" "(signed_take_bit :: nat \ int \ int) (numeral k) (numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \ int \ int) (pred_numeral k) (numeral w)" "(signed_take_bit :: nat \ int \ int) (numeral k) (- numeral (Num.Bit0 w)) = 2 * (signed_take_bit :: nat \ int \ int) (pred_numeral k) (- numeral w)" "(signed_take_bit :: nat \ int \ int) (numeral k) (- numeral (Num.Bit1 w)) = 1 + 2 * (signed_take_bit :: nat \ int \ int) (pred_numeral k) (- numeral (w + Num.One))" "(signed_take_bit :: nat \ int \ int) (numeral k) 1 = 1" by (simp_all add: sbintrunc_numeral) lemma no_bintr_alt1: "(take_bit :: nat \ int \ int) n = (\w. w mod 2 ^ n :: int)" by (rule ext) (rule bintrunc_mod2p) lemma range_bintrunc: "range ((take_bit :: nat \ int \ int) n) = {i. 0 \ i \ i < 2 ^ n}" by (auto simp add: take_bit_eq_mod image_iff) (metis mod_pos_pos_trivial) lemma no_sbintr_alt2: "(signed_take_bit :: nat \ int \ int) n = (\w. (w + 2 ^ n) mod 2 ^ Suc n - 2 ^ n :: int)" by (rule ext) (simp add : sbintrunc_mod2p) lemma range_sbintrunc: "range ((signed_take_bit :: nat \ int \ int) n) = {i. - (2 ^ n) \ i \ i < 2 ^ n}" proof - have \surj (\k::int. k + 2 ^ n)\ by (rule surjI [of _ \(\k. k - 2 ^ n)\]) simp moreover have \(signed_take_bit :: nat \ int \ int) n = ((\k. k - 2 ^ n) \ take_bit (Suc n) \ (\k. k + 2 ^ n))\ by (simp add: sbintrunc_eq_take_bit fun_eq_iff) ultimately show ?thesis apply (simp only: fun.set_map range_bintrunc) apply (auto simp add: image_iff) apply presburger done qed lemma sbintrunc_inc: \k + 2 ^ Suc n \ (signed_take_bit :: nat \ int \ int) n k\ if \k < - (2 ^ n)\ using that by (fact signed_take_bit_int_greater_eq) lemma sbintrunc_dec: \(signed_take_bit :: nat \ int \ int) n k \ k - 2 ^ (Suc n)\ if \k \ 2 ^ n\ using that by (fact signed_take_bit_int_less_eq) lemma bintr_ge0: "0 \ (take_bit :: nat \ int \ int) n w" by (simp add: bintrunc_mod2p) lemma bintr_lt2p: "(take_bit :: nat \ int \ int) n w < 2 ^ n" by (simp add: bintrunc_mod2p) lemma bintr_Min: "(take_bit :: nat \ int \ int) n (- 1) = 2 ^ n - 1" by (simp add: stable_imp_take_bit_eq) lemma sbintr_ge: "- (2 ^ n) \ (signed_take_bit :: nat \ int \ int) n w" by (fact signed_take_bit_int_greater_eq_minus_exp) lemma sbintr_lt: "(signed_take_bit :: nat \ int \ int) n w < 2 ^ n" by (fact signed_take_bit_int_less_exp) 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: "(\k::int. k div 2) ((take_bit :: nat \ int \ int) n bin) = (take_bit :: nat \ int \ int) (n - 1) ((\k::int. k div 2) bin)" by (simp add: take_bit_rec [of n bin]) lemma bin_rest_power_trunc: "((\k::int. k div 2) ^^ k) ((take_bit :: nat \ int \ int) n bin) = (take_bit :: nat \ int \ int) (n - k) (((\k::int. k div 2) ^^ k) bin)" by (induct k) (auto simp: bin_rest_trunc) lemma bin_rest_trunc_i: "(take_bit :: nat \ int \ int) n ((\k::int. k div 2) bin) = (\k::int. k div 2) ((take_bit :: nat \ int \ int) (Suc n) bin)" by (auto simp add: take_bit_Suc) lemma bin_rest_strunc: "(\k::int. k div 2) ((signed_take_bit :: nat \ int \ int) (Suc n) bin) = (signed_take_bit :: nat \ int \ int) n ((\k::int. k div 2) bin)" by (simp add: signed_take_bit_Suc) lemma bintrunc_rest [simp]: "(take_bit :: nat \ int \ int) n ((\k::int. k div 2) ((take_bit :: nat \ int \ int) n bin)) = (\k::int. k div 2) ((take_bit :: nat \ int \ int) n bin)" by (induct n arbitrary: bin) (simp_all add: take_bit_Suc) lemma sbintrunc_rest [simp]: "(signed_take_bit :: nat \ int \ int) n ((\k::int. k div 2) ((signed_take_bit :: nat \ int \ int) n bin)) = (\k::int. k div 2) ((signed_take_bit :: nat \ int \ int) n bin)" by (induct n arbitrary: bin) (simp_all add: signed_take_bit_Suc mod2_eq_if) lemma bintrunc_rest': "(take_bit :: nat \ int \ int) n \ (\k::int. k div 2) \ (take_bit :: nat \ int \ int) n = (\k::int. k div 2) \ (take_bit :: nat \ int \ int) n" by (rule ext) auto lemma sbintrunc_rest': "(signed_take_bit :: nat \ int \ int) n \ (\k::int. k div 2) \ (signed_take_bit :: nat \ int \ int) n = (\k::int. k div 2) \ (signed_take_bit :: nat \ int \ int) 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 (w div 2) in (w1, of_bool (odd w) + 2 * w2))" "bin_split 0 w = (w, 0)" by (simp_all add: drop_bit_Suc take_bit_Suc mod_2_eq_odd) lemma bin_cat_eq_push_bit_add_take_bit: \concat_bit n l k = push_bit n k + take_bit n l\ by (simp add: concat_bit_eq) lemma bin_sign_cat: "bin_sign ((\k n l. concat_bit n l k) x n y) = bin_sign x" proof - have \0 \ x\ if \0 \ x * 2 ^ n + y mod 2 ^ n\ proof - have \y mod 2 ^ n < 2 ^ n\ using pos_mod_bound [of \2 ^ n\ y] by simp then have \\ y mod 2 ^ n \ 2 ^ n\ by (simp add: less_le) with that have \x \ - 1\ by auto have *: \- 1 \ (- (y mod 2 ^ n)) div 2 ^ n\ by (simp add: zdiv_zminus1_eq_if) from that have \- (y mod 2 ^ n) \ x * 2 ^ n\ by simp then have \(- (y mod 2 ^ n)) div 2 ^ n \ (x * 2 ^ n) div 2 ^ n\ using zdiv_mono1 zero_less_numeral zero_less_power by blast with * have \- 1 \ x * 2 ^ n div 2 ^ n\ by simp with \x \ - 1\ show ?thesis by simp qed then show ?thesis by (simp add: bin_sign_def not_le not_less bin_cat_eq_push_bit_add_take_bit push_bit_eq_mult take_bit_eq_mod) qed lemma bin_cat_assoc: "(\k n l. concat_bit n l k) ((\k n l. concat_bit n l k) x m y) n z = (\k n l. concat_bit n l k) x (m + n) ((\k n l. concat_bit n l k) y n z)" by (fact concat_bit_assoc) lemma bin_cat_assoc_sym: "(\k n l. concat_bit n l k) x m ((\k n l. concat_bit n l k) y n z) = (\k n l. concat_bit n l k) ((\k n l. concat_bit n l k) x (m - n) y) (min m n) z" by (fact concat_bit_assoc_sym) definition bin_rcat :: \nat \ int list \ int\ where \bin_rcat n = horner_sum (take_bit n) (2 ^ n) \ rev\ lemma bin_rcat_eq_foldl: \bin_rcat n = foldl (\u v. (\k n l. concat_bit n l k) u n v) 0\ proof fix ks :: \int list\ show \bin_rcat n ks = foldl (\u v. (\k n l. concat_bit n l k) u n v) 0 ks\ by (induction ks rule: rev_induct) (simp_all add: bin_rcat_def concat_bit_eq push_bit_eq_mult) qed fun bin_rsplit_aux :: "nat \ 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: "(bit :: int \ nat \ bool) ((\k n l. concat_bit n l k) x k y) n = (if n < k then (bit :: int \ nat \ bool) y n else (bit :: int \ nat \ bool) x (n - k))" by (simp add: bit_concat_bit_iff) lemma bin_nth_drop_bit_iff: \(bit :: int \ nat \ bool) (drop_bit n c) k \ (bit :: int \ nat \ bool) c (n + k)\ by (simp add: bit_drop_bit_eq) lemma bin_nth_take_bit_iff: \(bit :: int \ nat \ bool) (take_bit n c) k \ k < n \ (bit :: int \ nat \ bool) c k\ by (fact bit_take_bit_iff) lemma bin_nth_split: "bin_split n c = (a, b) \ (\k. (bit :: int \ nat \ bool) a k = (bit :: int \ nat \ bool) c (n + k)) \ (\k. (bit :: int \ nat \ bool) b k = (k < n \ (bit :: int \ nat \ bool) c k))" by (auto simp add: bin_nth_drop_bit_iff bin_nth_take_bit_iff) lemma bin_cat_zero [simp]: "(\k n l. concat_bit n l k) 0 n w = (take_bit :: nat \ int \ int) n w" by (simp add: bin_cat_eq_push_bit_add_take_bit) lemma bintr_cat1: "(take_bit :: nat \ int \ int) (k + n) ((\k n l. concat_bit n l k) a n b) = (\k n l. concat_bit n l k) ((take_bit :: nat \ int \ int) k a) n b" by (metis bin_cat_assoc bin_cat_zero) lemma bintr_cat: "(take_bit :: nat \ int \ int) m ((\k n l. concat_bit n l k) a n b) = (\k n l. concat_bit n l k) ((take_bit :: nat \ int \ int) (m - n) a) n ((take_bit :: nat \ int \ int) (min m n) b)" by (rule bin_eqI) (auto simp: bin_nth_cat nth_bintr) lemma bintr_cat_same [simp]: "(take_bit :: nat \ int \ int) n ((\k n l. concat_bit n l k) a n b) = (take_bit :: nat \ int \ int) n b" by (auto simp add : bintr_cat) lemma cat_bintr [simp]: "(\k n l. concat_bit n l k) a n ((take_bit :: nat \ int \ int) n b) = (\k n l. concat_bit n l k) a n b" by (simp add: bin_cat_eq_push_bit_add_take_bit) lemma split_bintrunc: "bin_split n c = (a, b) \ b = (take_bit :: nat \ int \ int) n c" by simp lemma bin_cat_split: "bin_split n w = (u, v) \ w = (\k n l. concat_bit n l k) u n v" by (auto simp add: bin_cat_eq_push_bit_add_take_bit bits_ident) lemma drop_bit_bin_cat_eq: \drop_bit n ((\k n l. concat_bit n l k) v n w) = v\ by (rule bit_eqI) (simp add: bit_drop_bit_eq bit_concat_bit_iff) lemma take_bit_bin_cat_eq: \take_bit n ((\k n l. concat_bit n l k) v n w) = take_bit n w\ by (rule bit_eqI) (simp add: bit_concat_bit_iff) lemma bin_split_cat: "bin_split n ((\k n l. concat_bit n l k) v n w) = (v, (take_bit :: nat \ int \ int) n w)" by (simp add: drop_bit_bin_cat_eq take_bit_bin_cat_eq) lemma bin_split_zero [simp]: "bin_split n 0 = (0, 0)" by simp lemma bin_split_minus1 [simp]: "bin_split n (- 1) = (- 1, (take_bit :: nat \ int \ int) n (- 1))" by simp lemma bin_split_trunc: "bin_split (min m n) c = (a, b) \ bin_split n ((take_bit :: nat \ int \ int) m c) = ((take_bit :: nat \ int \ int) (m - n) a, b)" apply (induct n arbitrary: m b c, clarsimp) apply (simp add: bin_rest_trunc Let_def split: prod.split_asm) apply (case_tac m) apply (auto simp: Let_def drop_bit_Suc take_bit_Suc mod_2_eq_odd split: prod.split_asm) done lemma bin_split_trunc1: "bin_split n c = (a, b) \ bin_split n ((take_bit :: nat \ int \ int) m c) = ((take_bit :: nat \ int \ int) (m - n) a, (take_bit :: nat \ int \ int) m b)" apply (induct n arbitrary: m b c, clarsimp) apply (simp add: bin_rest_trunc Let_def split: prod.split_asm) apply (case_tac m) apply (auto simp: Let_def drop_bit_Suc take_bit_Suc mod_2_eq_odd split: prod.split_asm) done lemma bin_cat_num: "(\k n l. concat_bit n l k) a n b = a * 2 ^ n + (take_bit :: nat \ int \ int) n b" by (simp add: bin_cat_eq_push_bit_add_take_bit push_bit_eq_mult) lemma bin_split_num: "bin_split n b = (b div 2 ^ n, b mod 2 ^ n)" by (simp add: drop_bit_eq_div take_bit_eq_mod) lemmas bin_rsplit_aux_simps = bin_rsplit_aux.simps bin_rsplitl_aux.simps lemmas rsplit_aux_simps = bin_rsplit_aux_simps lemmas th_if_simp1 = if_split [where P = "(=) l", THEN iffD1, THEN conjunct1, THEN mp] for l lemmas th_if_simp2 = if_split [where P = "(=) l", THEN iffD1, THEN conjunct2, THEN mp] for l lemmas rsplit_aux_simp1s = rsplit_aux_simps [THEN th_if_simp1] lemmas rsplit_aux_simp2ls = rsplit_aux_simps [THEN th_if_simp2] \ \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) ((\k::int. k div 2) w) in (w1, of_bool (odd w) + 2 * w2))" by (simp add: take_bit_rec drop_bit_rec mod_2_eq_odd) lemma bin_rsplit_aux_simp_alt: "bin_rsplit_aux n m c bs = (if m = 0 \ 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. (take_bit :: nat \ int \ int) n v = v" apply (induct sw arbitrary: nw w) apply clarsimp apply clarsimp apply (drule bthrs) apply (simp (no_asm_use) add: Let_def split: prod.split_asm if_split_asm) apply clarify apply simp done lemmas bin_rsplit_size_sign = bin_rsplit_size_sign' [OF asm_rl rev_rev_ident [THEN trans] set_rev [THEN equalityD2 [THEN subsetD]]] lemma bin_nth_rsplit [rule_format] : "n > 0 \ m < n \ \w k nw. rev sw = bin_rsplit n (nw, w) \ k < size sw \ (bit :: int \ nat \ bool) (sw ! k) m = (bit :: int \ nat \ bool) w (k * n + m)" apply (induct sw) apply clarsimp apply clarsimp apply (drule bthrs) apply (simp (no_asm_use) add: Let_def split: prod.split_asm if_split_asm) apply (erule allE, erule impE, erule exI) apply (case_tac k) apply clarsimp prefer 2 apply clarsimp apply (erule allE) apply (erule (1) impE) apply (simp add: bit_drop_bit_eq ac_simps) apply (simp add: bit_take_bit_iff ac_simps) done lemma bin_rsplit_all: "0 < nw \ nw \ n \ bin_rsplit n (nw, w) = [(take_bit :: nat \ int \ int) 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, (take_bit :: nat \ int \ int) m bin)" apply (rule_tac a = "m" in wf_less_than [THEN wf_induct]) apply (simp (no_asm) add: bin_rsplitl_def bin_rsplit_def) apply (rule allI) apply (subst bin_rsplitl_aux.simps) apply (subst bin_rsplit_aux.simps) apply (clarsimp simp: Let_def split: prod.split) apply (simp add: ac_simps) apply (subst rsplit_aux_alts(1)) apply (subst rsplit_aux_alts(2)) apply clarsimp unfolding bin_rsplit_def bin_rsplitl_def apply (simp add: drop_bit_take_bit) apply (case_tac \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 ((take_bit :: nat \ int \ int) n) ws" apply (unfold bin_rsplit_def bin_rcat_eq_foldl) apply (rule_tac xs = ws in rev_induct) apply clarsimp apply clarsimp apply (subst rsplit_aux_alts) apply (simp add: drop_bit_bin_cat_eq take_bit_bin_cat_eq) done lemma bin_rsplit_aux_len_le [rule_format] : "\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\ -instantiation int :: set_bit -begin - -definition set_bit_int :: \int \ nat \ bool \ int\ - where \set_bit_int i n b = (if b then Bit_Operations.set_bit else Bit_Operations.unset_bit) n i\ - -instance - by standard (simp_all add: set_bit_int_def bit_simps) - -end - abbreviation (input) bin_sc :: \nat \ bool \ int \ int\ where \bin_sc n b i \ set_bit i n b\ lemma bin_sc_0 [simp]: "bin_sc 0 b w = of_bool b + 2 * (\k::int. k div 2) w" by (simp add: set_bit_int_def) lemma bin_sc_Suc [simp]: "bin_sc (Suc n) b w = of_bool (odd w) + 2 * bin_sc n b (w div 2)" by (simp add: set_bit_int_def set_bit_Suc unset_bit_Suc bin_last_def) lemma bin_nth_sc [bit_simps]: "bit (bin_sc n b w) n \ b" by (simp add: bit_simps) lemma bin_sc_sc_same [simp]: "bin_sc n c (bin_sc n b w) = bin_sc n c w" by (induction n arbitrary: w) (simp_all add: bit_Suc) lemma bin_sc_sc_diff: "m \ 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: "(bit :: int \ nat \ bool) (bin_sc n b w) m = (if m = n then b else (bit :: int \ nat \ bool) w m)" apply (induct n arbitrary: w m) apply (case_tac m; simp add: bit_Suc) apply (case_tac m; simp add: bit_Suc) done lemma bin_sc_eq: \bin_sc n False = unset_bit n\ \bin_sc n True = Bit_Operations.set_bit n\ apply (simp_all add: fun_eq_iff bit_eq_iff) apply (simp_all add: bit_simps bin_nth_sc_gen) done lemma bin_sc_nth [simp]: "bin_sc n ((bit :: int \ nat \ bool) w n) w = w" by (rule bit_eqI) (simp add: bin_nth_sc_gen) lemma bin_sign_sc [simp]: "bin_sign (bin_sc n b w) = bin_sign w" proof (induction n arbitrary: w) case 0 then show ?case by (auto simp add: bin_sign_def) (use bin_rest_ge_0 in fastforce) next case (Suc n) from Suc [of \w div 2\] show ?case by (auto simp add: bin_sign_def split: if_splits) qed lemma bin_sc_bintr [simp]: "(take_bit :: nat \ int \ int) m (bin_sc n x ((take_bit :: nat \ int \ int) m w)) = (take_bit :: nat \ int \ int) m (bin_sc n x w)" apply (rule bit_eqI) apply (cases x) apply (auto simp add: bit_simps bin_sc_eq) done lemma bin_clr_le: "bin_sc n False w \ w" by (simp add: set_bit_int_def unset_bit_less_eq) lemma bin_set_ge: "bin_sc n True w \ w" by (simp add: set_bit_int_def set_bit_greater_eq) lemma bintr_bin_clr_le: "(take_bit :: nat \ int \ int) n (bin_sc m False w) \ (take_bit :: nat \ int \ int) n w" by (simp add: set_bit_int_def take_bit_unset_bit_eq unset_bit_less_eq) lemma bintr_bin_set_ge: "(take_bit :: nat \ int \ int) n (bin_sc m True w) \ (take_bit :: nat \ int \ int) n w" by (simp add: set_bit_int_def take_bit_set_bit_eq set_bit_greater_eq) lemma bin_sc_FP [simp]: "bin_sc n False 0 = 0" by (induct n) auto lemma bin_sc_TM [simp]: "bin_sc n True (- 1) = - 1" by (induct n) auto lemmas bin_sc_simps = bin_sc_0 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 = of_bool (odd w) + 2 * bin_sc (pred_numeral k) b (w div 2)" by (simp add: numeral_eq_Suc) lemmas bin_sc_minus_simps = bin_sc_simps (2,3,4) [THEN [2] trans, OF bin_sc_minus [THEN sym]] lemma int_set_bit_0 [simp]: fixes x :: int shows "set_bit x 0 b = of_bool b + 2 * (x div 2)" by (fact bin_sc_0) lemma int_set_bit_Suc: fixes x :: int shows "set_bit x (Suc n) b = of_bool (odd x) + 2 * set_bit (x div 2) n b" by (fact bin_sc_Suc) lemma bin_last_set_bit: "odd (set_bit x n b :: int) = (if n > 0 then odd x else b)" by (cases n) (simp_all add: int_set_bit_Suc) lemma bin_rest_set_bit: "(set_bit x n b :: int) div 2 = (if n > 0 then set_bit (x div 2) (n - 1) b else x div 2)" 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 = of_bool (odd x) + 2 * set_bit (x div 2) (pred_numeral w) b" by (fact bin_sc_numeral) 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 msb_set_bit [simp]: "msb (set_bit (x :: int) n b) \ msb x" - by (smt (z3) Bits_Int.set_bit_int_def bin_sign_def bin_sign_sc msb_int_def) + by (simp add: msb_int_def set_bit_int_def) lemma word_set_bit_def: \set_bit a n x = word_of_int (bin_sc n x (uint a))\ apply (rule bit_word_eqI) apply (cases x) apply (simp_all add: bit_simps bin_sc_eq) done lemma set_bit_word_of_int: "set_bit (word_of_int x) n b = word_of_int (bin_sc n b x)" unfolding word_set_bit_def by (rule word_eqI) (simp add: word_size bin_nth_sc_gen nth_bintr bit_simps) lemma word_set_numeral [simp]: "set_bit (numeral bin::'a::len word) n b = word_of_int (bin_sc n b (numeral bin))" unfolding word_numeral_alt by (rule set_bit_word_of_int) lemma word_set_neg_numeral [simp]: "set_bit (- numeral bin::'a::len word) n b = word_of_int (bin_sc n b (- numeral bin))" unfolding word_neg_numeral_alt by (rule set_bit_word_of_int) lemma word_set_bit_0 [simp]: "set_bit 0 n b = word_of_int (bin_sc n b 0)" unfolding word_0_wi by (rule set_bit_word_of_int) lemma word_set_bit_1 [simp]: "set_bit 1 n b = word_of_int (bin_sc n b 1)" unfolding word_1_wi by (rule set_bit_word_of_int) lemma shiftl_int_def: "push_bit n x = x * 2 ^ n" for x :: int by (fact push_bit_eq_mult) lemma shiftr_int_def: "drop_bit n x = x div 2 ^ n" for x :: int by (fact drop_bit_eq_div) subsubsection \Basic simplification rules\ lemmas int_not_def = not_int_def lemma int_not_simps: "NOT (0::int) = -1" "NOT (1::int) = -2" "NOT (- 1::int) = 0" "NOT (numeral w::int) = - numeral (w + Num.One)" "NOT (- numeral (Num.Bit0 w)::int) = numeral (Num.BitM w)" "NOT (- numeral (Num.Bit1 w)::int) = numeral (Num.Bit0 w)" by (simp_all add: not_int_def) lemma int_not_not: "NOT (NOT x) = x" for x :: int by (fact bit.double_compl) lemma int_and_0 [simp]: "0 AND x = 0" for x :: int by (fact bit.conj_zero_left) lemma int_and_m1 [simp]: "-1 AND x = x" for x :: int by (fact bit.conj_one_left) lemma int_or_zero [simp]: "0 OR x = x" for x :: int by (fact bit.disj_zero_left) lemma int_or_minus1 [simp]: "-1 OR x = -1" for x :: int by (fact bit.disj_one_left) lemma int_xor_zero [simp]: "0 XOR x = x" for x :: int by (fact bit.xor_zero_left) subsubsection \Binary destructors\ lemma bin_rest_NOT [simp]: "(\k::int. k div 2) (NOT x) = NOT ((\k::int. k div 2) x)" by (fact not_int_div_2) lemma bin_last_NOT [simp]: "(odd :: int \ bool) (NOT x) \ \ (odd :: int \ bool) x" by simp lemma bin_rest_AND [simp]: "(\k::int. k div 2) (x AND y) = (\k::int. k div 2) x AND (\k::int. k div 2) y" by (subst and_int_rec) auto lemma bin_last_AND [simp]: "(odd :: int \ bool) (x AND y) \ (odd :: int \ bool) x \ (odd :: int \ bool) y" by (subst and_int_rec) auto lemma bin_rest_OR [simp]: "(\k::int. k div 2) (x OR y) = (\k::int. k div 2) x OR (\k::int. k div 2) y" by (subst or_int_rec) auto lemma bin_last_OR [simp]: "(odd :: int \ bool) (x OR y) \ (odd :: int \ bool) x \ (odd :: int \ bool) y" by (subst or_int_rec) auto lemma bin_rest_XOR [simp]: "(\k::int. k div 2) (x XOR y) = (\k::int. k div 2) x XOR (\k::int. k div 2) y" by (subst xor_int_rec) auto lemma bin_last_XOR [simp]: "(odd :: int \ bool) (x XOR y) \ ((odd :: int \ bool) x \ (odd :: int \ bool) y) \ \ ((odd :: int \ bool) x \ (odd :: int \ bool) y)" by (subst xor_int_rec) auto lemma bin_nth_ops: "\x y. (bit :: int \ nat \ bool) (x AND y) n \ (bit :: int \ nat \ bool) x n \ (bit :: int \ nat \ bool) y n" "\x y. (bit :: int \ nat \ bool) (x OR y) n \ (bit :: int \ nat \ bool) x n \ (bit :: int \ nat \ bool) y n" "\x y. (bit :: int \ nat \ bool) (x XOR y) n \ (bit :: int \ nat \ bool) x n \ (bit :: int \ nat \ bool) y n" "\x. (bit :: int \ nat \ bool) (NOT x) n \ \ (bit :: int \ nat \ bool) 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) subsubsection \Simplification with numerals\ text \Cases for \0\ and \-1\ are already covered by other simp rules.\ lemma bin_rest_neg_numeral_BitM [simp]: "(\k::int. k div 2) (- numeral (Num.BitM w)) = - numeral w" by simp lemma bin_last_neg_numeral_BitM [simp]: "(odd :: int \ bool) (- numeral (Num.BitM w))" by simp subsubsection \Interactions with arithmetic\ lemma le_int_or: "bin_sign y = 0 \ x \ x OR y" for x y :: int by (simp add: bin_sign_def or_greater_eq split: if_splits) lemmas int_and_le = xtrans(3) [OF bbw_ao_absorbs (2) [THEN conjunct2, symmetric] le_int_or] text \Interaction between bit-wise and arithmetic: good example of \bin_induction\.\ lemma bin_add_not: "x + NOT x = (-1::int)" by (simp add: not_int_def) lemma AND_mod: "x AND (2 ^ n - 1) = x mod 2 ^ n" for x :: int by (simp flip: take_bit_eq_mod add: take_bit_eq_mask mask_eq_exp_minus_1) subsubsection \Truncating results of bit-wise operations\ lemma bin_trunc_ao: "(take_bit :: nat \ int \ int) n x AND (take_bit :: nat \ int \ int) n y = (take_bit :: nat \ int \ int) n (x AND y)" "(take_bit :: nat \ int \ int) n x OR (take_bit :: nat \ int \ int) n y = (take_bit :: nat \ int \ int) n (x OR y)" by simp_all lemma bin_trunc_xor: "(take_bit :: nat \ int \ int) n ((take_bit :: nat \ int \ int) n x XOR (take_bit :: nat \ int \ int) n y) = (take_bit :: nat \ int \ int) n (x XOR y)" by simp lemma bin_trunc_not: "(take_bit :: nat \ int \ int) n (NOT ((take_bit :: nat \ int \ int) n x)) = (take_bit :: nat \ int \ int) n (NOT x)" by (fact take_bit_not_take_bit) text \Want theorems of the form of \bin_trunc_xor\.\ lemma bintr_bintr_i: "x = (take_bit :: nat \ int \ int) n y \ (take_bit :: nat \ int \ int) n x = (take_bit :: nat \ int \ int) n y" by auto lemmas bin_trunc_and = bin_trunc_ao(1) [THEN bintr_bintr_i] lemmas bin_trunc_or = bin_trunc_ao(2) [THEN bintr_bintr_i] subsubsection \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: "(odd :: int \ bool) i \ i AND 1 \ 0" by (simp add: and_one_eq mod2_eq_if) lemma bitval_bin_last: "of_bool ((odd :: int \ bool) i) = i AND 1" by (simp add: and_one_eq mod2_eq_if) lemma bin_sign_and: "bin_sign (i AND j) = - (bin_sign i * bin_sign j)" by(simp add: bin_sign_def) lemma int_not_neg_numeral: "NOT (- numeral n) = (Num.sub n num.One :: int)" by(simp add: int_not_def) lemma int_neg_numeral_pOne_conv_not: "- numeral (n + num.One) = (NOT (numeral n) :: int)" by(simp add: int_not_def) subsection \Setting and clearing bits\ lemma int_shiftl_BIT: fixes x :: int shows int_shiftl0: "push_bit 0 x = x" and int_shiftl_Suc: "push_bit (Suc n) x = 2 * push_bit n x" by (auto simp add: shiftl_int_def) lemma int_0_shiftl: "push_bit n 0 = (0 :: int)" by (fact push_bit_of_0) lemma bin_last_shiftl: "odd (push_bit n x) \ n = 0 \ (odd :: int \ bool) x" by simp lemma bin_rest_shiftl: "(\k::int. k div 2) (push_bit n x) = (if n > 0 then push_bit (n - 1) x else (\k::int. k div 2) x)" by (cases n) (simp_all add: push_bit_eq_mult) lemma bin_nth_shiftl: "(bit :: int \ nat \ bool) (push_bit n x) m \ n \ m \ (bit :: int \ nat \ bool) x (m - n)" by (fact bit_push_bit_iff_int) lemma bin_last_shiftr: "odd (drop_bit n x) \ bit x n" for x :: int by (simp add: bit_iff_odd_drop_bit) lemma bin_rest_shiftr: "(\k::int. k div 2) (drop_bit n x) = drop_bit (Suc n) x" by (simp add: drop_bit_Suc drop_bit_half) lemma bin_nth_shiftr: "(bit :: int \ nat \ bool) (drop_bit n x) m = (bit :: int \ nat \ bool) x (n + m)" by (simp add: bit_simps) lemma bin_nth_conv_AND: fixes x :: int shows "(bit :: int \ nat \ bool) x n \ x AND (push_bit n 1) \ 0" by (fact bit_iff_and_push_bit_not_eq_0) lemma int_shiftl_numeral [simp]: "push_bit (numeral w') (numeral w :: int) = push_bit (pred_numeral w') (numeral (num.Bit0 w))" "push_bit (numeral w') (- numeral w :: int) = push_bit (pred_numeral w') (- numeral (num.Bit0 w))" by(simp_all add: numeral_eq_Suc shiftl_int_def) (metis add_One mult_inc semiring_norm(11) semiring_norm(13) semiring_norm(2) semiring_norm(6) semiring_norm(87))+ lemma int_shiftl_One_numeral [simp]: "push_bit (numeral w) (1::int) = push_bit (pred_numeral w) 2" using int_shiftl_numeral [of Num.One w] by (simp add: numeral_eq_Suc) lemma shiftl_ge_0: fixes i :: int shows "push_bit n i \ 0 \ i \ 0" by (fact push_bit_nonnegative_int_iff) lemma shiftl_lt_0: fixes i :: int shows "push_bit n i < 0 \ i < 0" by (fact push_bit_negative_int_iff) lemma int_shiftl_test_bit: "bit (push_bit i n :: int) m \ m \ i \ bit n (m - i)" by (fact bit_push_bit_iff_int) lemma int_0shiftr: "drop_bit x (0 :: int) = 0" by (fact drop_bit_of_0) lemma int_minus1_shiftr: "drop_bit x (-1 :: int) = -1" by (fact drop_bit_minus_one) lemma int_shiftr_ge_0: fixes i :: int shows "drop_bit n i \ 0 \ i \ 0" by (fact drop_bit_nonnegative_int_iff) lemma int_shiftr_lt_0 [simp]: fixes i :: int shows "drop_bit n i < 0 \ i < 0" by (fact drop_bit_negative_int_iff) lemma int_shiftr_numeral [simp]: "drop_bit (numeral w') (1 :: int) = 0" "drop_bit (numeral w') (numeral num.One :: int) = 0" "drop_bit (numeral w') (numeral (num.Bit0 w) :: int) = drop_bit (pred_numeral w') (numeral w)" "drop_bit (numeral w') (numeral (num.Bit1 w) :: int) = drop_bit (pred_numeral w') (numeral w)" "drop_bit (numeral w') (- numeral (num.Bit0 w) :: int) = drop_bit (pred_numeral w') (- numeral w)" "drop_bit (numeral w') (- numeral (num.Bit1 w) :: int) = drop_bit (pred_numeral w') (- numeral (Num.inc w))" by (simp_all add: numeral_eq_Suc add_One drop_bit_Suc) lemma int_shiftr_numeral_Suc0 [simp]: "drop_bit (Suc 0) (1 :: int) = 0" "drop_bit (Suc 0) (numeral num.One :: int) = 0" "drop_bit (Suc 0) (numeral (num.Bit0 w) :: int) = numeral w" "drop_bit (Suc 0) (numeral (num.Bit1 w) :: int) = numeral w" "drop_bit (Suc 0) (- numeral (num.Bit0 w) :: int) = - numeral w" "drop_bit (Suc 0) (- numeral (num.Bit1 w) :: int) = - numeral (Num.inc w)" by (simp_all add: drop_bit_Suc add_One) lemma bin_nth_minus_p2: assumes sign: "bin_sign x = 0" and y: "y = push_bit n 1" and m: "m < n" and x: "x < y" shows "bit (x - y) m = bit x m" proof - from sign y x have \x \ 0\ and \y = 2 ^ n\ and \x < 2 ^ n\ by (simp_all add: bin_sign_def push_bit_eq_mult split: if_splits) from \0 \ x\ \x < 2 ^ n\ \m < n\ have \bit x m \ bit (x - 2 ^ n) m\ proof (induction m arbitrary: x n) case 0 then show ?case by simp next case (Suc m) moreover define q where \q = n - 1\ ultimately have n: \n = Suc q\ by simp have \(x - 2 ^ Suc q) div 2 = x div 2 - 2 ^ q\ by simp moreover from Suc.IH [of \x div 2\ q] Suc.prems have \bit (x div 2) m \ bit (x div 2 - 2 ^ q) m\ by (simp add: n) ultimately show ?case by (simp add: bit_Suc n) qed with \y = 2 ^ n\ show ?thesis by simp qed lemma bin_clr_conv_NAND: "bin_sc n False i = i AND NOT (push_bit n 1)" by (rule bit_eqI) (auto simp add: bin_sc_eq bit_simps) lemma bin_set_conv_OR: "bin_sc n True i = i OR (push_bit n 1)" by (rule bit_eqI) (auto simp add: bin_sc_eq bit_simps) subsection \More lemmas on words\ lemma msb_conv_bin_sign: "msb x \ bin_sign x = -1" by (simp add: bin_sign_def not_le 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_word_def: \msb a \ bin_sign (signed_take_bit (LENGTH('a) - 1) (uint a)) = - 1\ for a :: \'a::len word\ by (simp add: bin_sign_def bit_simps msb_word_iff_bit) lemma word_msb_def: "msb a \ bin_sign (sint a) = - 1" by (simp add: msb_word_def sint_uint) lemma word_rcat_eq: \word_rcat ws = word_of_int (bin_rcat (LENGTH('a::len)) (map uint ws))\ for ws :: \'a::len word list\ apply (simp add: word_rcat_def bin_rcat_def rev_map) apply transfer apply (simp add: horner_sum_foldr foldr_map comp_def) done lemma sign_uint_Pls [simp]: "bin_sign (uint x) = 0" by (simp add: sign_Pls_ge_0) lemmas bin_log_bintrs = bin_trunc_not bin_trunc_xor bin_trunc_and bin_trunc_or \ \following definitions require both arithmetic and bit-wise word operations\ \ \to get \word_no_log_defs\ from \word_log_defs\, using \bin_log_bintrs\\ lemmas wils1 = bin_log_bintrs [THEN word_of_int_eq_iff [THEN iffD2], folded uint_word_of_int_eq, THEN eq_reflection] \ \the binary operations only\ (* BH: why is this needed? *) lemmas word_log_binary_defs = word_and_def word_or_def word_xor_def lemma setBit_no: "Bit_Operations.set_bit n (numeral bin) = word_of_int (bin_sc n True (numeral bin))" by (rule bit_word_eqI) (simp add: bit_simps) lemma clearBit_no: "unset_bit n (numeral bin) = word_of_int (bin_sc n False (numeral bin))" by (rule bit_word_eqI) (simp add: bit_simps) lemma eq_mod_iff: "0 < n \ b = b mod n \ 0 \ b \ b < n" for b n :: int by auto (metis pos_mod_conj)+ lemma split_uint_lem: "bin_split n (uint w) = (a, b) \ a = take_bit (LENGTH('a) - n) a \ b = take_bit (LENGTH('a)) b" for w :: "'a::len word" by transfer (simp add: drop_bit_take_bit ac_simps) \ \limited hom result\ lemma word_cat_hom: "LENGTH('a::len) \ LENGTH('b::len) + LENGTH('c::len) \ (word_cat (word_of_int w :: 'b word) (b :: 'c word) :: 'a word) = word_of_int ((\k n l. concat_bit n l k) w (size b) (uint b))" by transfer (simp add: take_bit_concat_bit_eq) lemma bintrunc_shiftl: "take_bit n (push_bit i m) = push_bit i (take_bit (n - i) m)" for m :: int by (fact take_bit_push_bit) lemma uint_shiftl: "uint (push_bit i n) = take_bit (size n) (push_bit i (uint n))" by (simp add: unsigned_push_bit_eq word_size) lemma bin_mask_conv_pow2: "mask n = 2 ^ n - (1 :: int)" by (fact mask_eq_exp_minus_1) lemma bin_mask_ge0: "mask n \ (0 :: int)" by (fact mask_nonnegative_int) lemma and_bin_mask_conv_mod: "x AND mask n = x mod 2 ^ n" for x :: int by (simp flip: take_bit_eq_mod add: take_bit_eq_mask) lemma bin_mask_numeral: "mask (numeral n) = (1 :: int) + 2 * mask (pred_numeral n)" by (fact mask_numeral) lemma bin_nth_mask: "bit (mask n :: int) i \ i < n" by (simp add: bit_mask_iff) lemma bin_sign_mask [simp]: "bin_sign (mask n) = 0" by (simp add: bin_sign_def bin_mask_conv_pow2) lemma bin_mask_p1_conv_shift: "mask n + 1 = push_bit n (1 :: int)" by (simp add: bin_mask_conv_pow2 shiftl_int_def) lemma sbintrunc_eq_in_range: "((signed_take_bit :: nat \ int \ int) n x = x) = (x \ range ((signed_take_bit :: nat \ int \ int) n))" "(x = (signed_take_bit :: nat \ int \ int) n x) = (x \ range ((signed_take_bit :: nat \ int \ int) n))" apply (simp_all add: image_def) apply (metis sbintrunc_sbintrunc)+ done lemma sbintrunc_If: "- 3 * (2 ^ n) \ x \ x < 3 * (2 ^ n) \ (signed_take_bit :: nat \ int \ int) n x = (if x < - (2 ^ n) then x + 2 * (2 ^ n) else if x \ 2 ^ n then x - 2 * (2 ^ n) else x)" apply (simp add: no_sbintr_alt2, safe) apply (simp add: mod_pos_geq) apply (subst mod_add_self1[symmetric], simp) done lemma sint_range': \- (2 ^ (LENGTH('a) - Suc 0)) \ sint x \ sint x < 2 ^ (LENGTH('a) - Suc 0)\ for x :: \'a::len word\ apply transfer using sbintr_ge sbintr_lt apply auto done lemma signed_arith_eq_checks_to_ord: "(sint a + sint b = sint (a + b )) = ((a <=s a + b) = (0 <=s b))" "(sint a - sint b = sint (a - b )) = ((0 <=s a - b) = (b <=s a))" "(- sint a = sint (- a)) = (0 <=s (- a) = (a <=s 0))" using sint_range'[where x=a] sint_range'[where x=b] by (simp_all add: sint_word_ariths word_sle_eq word_sless_alt sbintrunc_If) lemma signed_mult_eq_checks_double_size: assumes mult_le: "(2 ^ (len_of TYPE ('a) - 1) + 1) ^ 2 \ (2 :: int) ^ (len_of TYPE ('b) - 1)" and le: "2 ^ (LENGTH('a) - 1) \ (2 :: int) ^ (len_of TYPE ('b) - 1)" shows "(sint (a :: 'a :: len word) * sint b = sint (a * b)) = (scast a * scast b = (scast (a * b) :: 'b :: len word))" proof - have P: "(signed_take_bit :: nat \ int \ int) (size a - 1) (sint a * sint b) \ range ((signed_take_bit :: nat \ int \ int) (size a - 1))" by simp have abs: "!! x :: 'a word. abs (sint x) < 2 ^ (size a - 1) + 1" apply (cut_tac x=x in sint_range') apply (simp add: abs_le_iff word_size) done have abs_ab: "abs (sint a * sint b) < 2 ^ (LENGTH('b) - 1)" using abs_mult_less[OF abs[where x=a] abs[where x=b]] mult_le by (simp add: abs_mult power2_eq_square word_size) define r s where \r = LENGTH('a) - 1\ \s = LENGTH('b) - 1\ then have \LENGTH('a) = Suc r\ \LENGTH('b) = Suc s\ \size a = Suc r\ \size b = Suc r\ by (simp_all add: word_size) then show ?thesis using P[unfolded range_sbintrunc] abs_ab le apply clarsimp apply (transfer fixing: r s) apply (auto simp add: signed_take_bit_int_eq_self min.absorb2 simp flip: signed_take_bit_eq_iff_take_bit_eq) done qed lemma bintrunc_id: "\m \ int n; 0 < m\ \ take_bit n m = m" by (simp add: take_bit_int_eq_self_iff le_less_trans less_exp) lemma bin_cat_cong: "concat_bit n b a = concat_bit m d c" if "n = m" "a = c" "take_bit m b = take_bit m d" using that(3) unfolding that(1,2) by (simp add: bin_cat_eq_push_bit_add_take_bit) lemma bin_cat_eqD1: "concat_bit n b a = concat_bit n d c \ a = c" by (metis drop_bit_bin_cat_eq) lemma bin_cat_eqD2: "concat_bit n b a = concat_bit n d c \ take_bit n b = take_bit n d" by (metis take_bit_bin_cat_eq) lemma bin_cat_inj: "(concat_bit n b a) = concat_bit n d c \ a = c \ take_bit n b = take_bit n d" by (auto intro: bin_cat_cong bin_cat_eqD1 bin_cat_eqD2) code_identifier code_module Bits_Int \ (SML) Bit_Operations and (OCaml) Bit_Operations and (Haskell) Bit_Operations and (Scala) Bit_Operations end diff --git a/thys/Word_Lib/Generic_set_bit.thy b/thys/Word_Lib/Generic_set_bit.thy --- a/thys/Word_Lib/Generic_set_bit.thy +++ b/thys/Word_Lib/Generic_set_bit.thy @@ -1,110 +1,121 @@ (* * Copyright Data61, CSIRO (ABN 41 687 119 230) * * SPDX-License-Identifier: BSD-2-Clause *) (* Author: Jeremy Dawson, NICTA *) section \Operation variant for setting and unsetting bits\ theory Generic_set_bit imports "HOL-Library.Word" Most_significant_bit begin class set_bit = semiring_bits + fixes set_bit :: \'a \ nat \ bool \ 'a\ assumes bit_set_bit_iff [bit_simps]: \bit (set_bit a m b) n \ (if m = n then b else bit a n) \ 2 ^ n \ 0\ lemma set_bit_eq: \set_bit a n b = (if b then Bit_Operations.set_bit else unset_bit) n a\ for a :: \'a::{ring_bit_operations, set_bit}\ by (rule bit_eqI) (simp add: bit_simps) +instantiation int :: set_bit +begin + +definition set_bit_int :: \int \ nat \ bool \ int\ + where \set_bit_int i n b = (if b then Bit_Operations.set_bit else Bit_Operations.unset_bit) n i\ + +instance + by standard (simp_all add: set_bit_int_def bit_simps) + +end + instantiation word :: (len) set_bit begin definition set_bit_word :: \'a word \ nat \ bool \ 'a word\ where set_bit_unfold: \set_bit w n b = (if b then Bit_Operations.set_bit n w else unset_bit n w)\ for w :: \'a::len word\ instance by standard (auto simp add: set_bit_unfold bit_simps dest: bit_imp_le_length) end lemma bit_set_bit_word_iff [bit_simps]: \bit (set_bit w m b) n \ (if m = n then n < LENGTH('a) \ b else bit w n)\ for w :: \'a::len word\ by (auto simp add: bit_simps dest: bit_imp_le_length) lemma test_bit_set_gen: "bit (set_bit w n x) m \ (if m = n then n < size w \ x else bit w m)" for w :: "'a::len word" by (simp add: bit_set_bit_word_iff word_size) lemma test_bit_set: "bit (set_bit w n x) n \ n < size w \ x" for w :: "'a::len word" by (auto simp add: bit_simps word_size) lemma word_set_nth: "set_bit w n (bit w n) = w" for w :: "'a::len word" by (rule bit_word_eqI) (simp add: bit_simps) lemma word_set_set_same [simp]: "set_bit (set_bit w n x) n y = set_bit w n y" for w :: "'a::len word" by (rule word_eqI) (simp add : test_bit_set_gen word_size) lemma word_set_set_diff: fixes w :: "'a::len word" assumes "m \ n" shows "set_bit (set_bit w m x) n y = set_bit (set_bit w n y) m x" by (rule word_eqI) (auto simp: test_bit_set_gen word_size assms) lemma word_set_nth_iff: "set_bit w n b = w \ bit w n = b \ n \ size w" for w :: "'a::len word" apply (rule iffI) apply (rule disjCI) apply (drule word_eqD) apply (erule sym [THEN trans]) apply (simp add: test_bit_set) apply (erule disjE) apply clarsimp apply (rule word_eqI) apply (clarsimp simp add : test_bit_set_gen) apply (auto simp add: word_size) apply (rule bit_eqI) apply (simp add: bit_simps) done lemma word_clr_le: "w \ set_bit w n False" for w :: "'a::len word" apply (simp add: set_bit_unfold) apply transfer apply (simp add: take_bit_unset_bit_eq unset_bit_less_eq) done lemma word_set_ge: "w \ set_bit w n True" for w :: "'a::len word" apply (simp add: set_bit_unfold) apply transfer apply (simp add: take_bit_set_bit_eq set_bit_greater_eq) done lemma set_bit_beyond: "size x \ n \ set_bit x n b = x" for x :: "'a :: len word" by (simp add: word_set_nth_iff) lemma one_bit_shiftl: "set_bit 0 n True = push_bit n (1 :: 'a :: len word)" apply (rule word_eqI) apply (auto simp add: word_size bit_simps) done lemmas one_bit_pow = trans [OF one_bit_shiftl push_bit_of_1] end diff --git a/thys/Word_Lib/Least_significant_bit.thy b/thys/Word_Lib/Least_significant_bit.thy --- a/thys/Word_Lib/Least_significant_bit.thy +++ b/thys/Word_Lib/Least_significant_bit.thy @@ -1,95 +1,94 @@ (* * Copyright Data61, CSIRO (ABN 41 687 119 230) * * SPDX-License-Identifier: BSD-2-Clause *) (* Author: Jeremy Dawson, NICTA *) section \Operation variant for the least significant bit\ theory Least_significant_bit imports "HOL-Library.Word" - Bits_Int More_Word begin class lsb = semiring_bits + fixes lsb :: \'a \ bool\ assumes lsb_odd: \lsb = odd\ instantiation int :: lsb begin definition lsb_int :: \int \ bool\ where \lsb i = bit i 0\ for i :: int instance by standard (simp add: fun_eq_iff lsb_int_def) end lemma bin_last_conv_lsb: "odd = (lsb :: int \ bool)" by (simp add: lsb_odd) 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) instantiation word :: (len) lsb begin definition lsb_word :: \'a word \ bool\ where word_lsb_def: \lsb a \ odd (uint a)\ for a :: \'a word\ instance apply standard apply (simp add: fun_eq_iff word_lsb_def) apply transfer apply simp done end lemma lsb_word_eq: \lsb = (odd :: 'a word \ bool)\ for w :: \'a::len word\ by (fact lsb_odd) lemma word_lsb_alt: "lsb w = bit w 0" for w :: "'a::len word" by (simp add: lsb_word_eq) lemma word_lsb_1_0 [simp]: "lsb (1::'a::len word) \ \ lsb (0::'b::len word)" unfolding word_lsb_def by simp lemma word_lsb_int: "lsb w \ uint w mod 2 = 1" apply (simp add: lsb_odd flip: odd_iff_mod_2_eq_one) apply transfer apply simp done lemmas word_ops_lsb = lsb0 [unfolded word_lsb_alt] lemma word_lsb_numeral [simp]: "lsb (numeral bin :: 'a::len word) \ odd (numeral bin :: int)" by (simp only: lsb_odd, transfer) rule lemma word_lsb_neg_numeral [simp]: "lsb (- numeral bin :: 'a::len word) \ odd (- numeral bin :: int)" by (simp only: lsb_odd, transfer) rule lemma word_lsb_nat:"lsb w = (unat w mod 2 = 1)" apply (simp add: word_lsb_def Groebner_Basis.algebra(31)) apply transfer apply (simp add: even_nat_iff) done end