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 @@ -1,175 +1,175 @@ (* 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 = ring_bit_operations + fixes set_bit :: \'a \ nat \ bool \ 'a\ assumes set_bit_eq: \set_bit a n b = (if b then Bit_Operations.set_bit else unset_bit) n a\ instantiation int :: set_bit begin definition set_bit_int :: \int \ nat \ bool \ int\ where \set_bit i n b = bin_sc n b i\ instance by standard (simp add: set_bit_int_def bin_sc_eq) end lemma int_set_bit_0 [simp]: fixes x :: int shows "set_bit x 0 b = of_bool b + 2 * (x div 2)" by (auto simp add: set_bit_int_def intro: bin_rl_eqI) lemma int_set_bit_Suc: fixes x :: int shows "set_bit x (Suc n) b = of_bool (odd x) + 2 * set_bit (x div 2) n b" by (auto simp add: set_bit_int_def intro: bin_rl_eqI) lemma bin_last_set_bit: "bin_last (set_bit x n b) = (if n > 0 then bin_last x else b)" by (cases n) (simp_all add: int_set_bit_Suc) lemma bin_rest_set_bit: "bin_rest (set_bit x n b) = (if n > 0 then set_bit (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 (simp add: set_bit_int_def) lemmas int_set_bit_numerals [simp] = int_set_bit_numeral[where x="numeral w'"] int_set_bit_numeral[where x="- numeral w'"] int_set_bit_numeral[where x="Numeral1"] int_set_bit_numeral[where x="1"] int_set_bit_numeral[where x="0"] int_set_bit_Suc[where x="numeral w'"] int_set_bit_Suc[where x="- numeral w'"] int_set_bit_Suc[where x="Numeral1"] int_set_bit_Suc[where x="1"] int_set_bit_Suc[where x="0"] for w' lemma msb_set_bit [simp]: "msb (set_bit (x :: int) n b) \ msb x" by(simp add: msb_conv_bin_sign set_bit_int_def) instantiation word :: (len) set_bit begin definition set_bit_word :: \'a word \ nat \ bool \ 'a word\ where word_set_bit_def: \set_bit a n x = word_of_int (bin_sc n x (uint a))\ instance apply standard apply (simp add: word_set_bit_def bin_sc_eq Bit_Operations.set_bit_def unset_bit_def) apply transfer apply simp done end lemma 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\ by (simp add: set_bit_eq) -lemma bit_set_bit_word_iff: +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: set_bit_unfold bit_unset_bit_iff bit_set_bit_iff exp_eq_zero_iff not_le bit_imp_le_length) lemma word_set_nth [simp]: "set_bit w n (test_bit w n) = w" for w :: "'a::len word" by (auto simp: word_test_bit_def word_set_bit_def) lemma test_bit_set: "(set_bit w n x) !! n \ n < size w \ x" for w :: "'a::len word" by (auto simp: word_size word_test_bit_def word_set_bit_def word_ubin.eq_norm nth_bintr) lemma test_bit_set_gen: "test_bit (set_bit w n x) m = (if m = n then n < size w \ x else test_bit w m)" for w :: "'a::len word" apply (unfold word_size word_test_bit_def word_set_bit_def) apply (clarsimp simp add: word_ubin.eq_norm nth_bintr bin_nth_sc_gen) apply (auto elim!: test_bit_size [unfolded word_size] simp add: word_test_bit_def [symmetric]) done 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 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 word_ubin.eq_norm nth_bintr) 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 word_set_nth_iff: "set_bit w n b = w \ 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 (drule test_bit_size) apply force done lemma word_clr_le: "w \ set_bit w n False" for w :: "'a::len word" apply (unfold word_set_bit_def word_le_def word_ubin.eq_norm) apply (rule order_trans) apply (rule bintr_bin_clr_le) apply simp done lemma word_set_ge: "w \ set_bit w n True" for w :: "'a::len word" apply (unfold word_set_bit_def word_le_def word_ubin.eq_norm) apply (rule order_trans [OF _ bintr_bin_set_ge]) apply simp done lemma set_bit_beyond: "size x \ n \ set_bit x n b = x" for x :: "'a :: len word" by (auto intro: word_eqI simp add: test_bit_set_gen word_size) lemma one_bit_shiftl: "set_bit 0 n True = (1 :: 'a :: len word) << n" apply (rule word_eqI) apply (auto simp add: test_bit_set_gen nth_shiftl word_size simp del: word_set_bit_0 shiftl_1) done lemmas one_bit_pow = trans [OF one_bit_shiftl shiftl_1] end diff --git a/thys/Word_Lib/Reversed_Bit_Lists.thy b/thys/Word_Lib/Reversed_Bit_Lists.thy --- a/thys/Word_Lib/Reversed_Bit_Lists.thy +++ b/thys/Word_Lib/Reversed_Bit_Lists.thy @@ -1,1869 +1,1869 @@ (* Author: Jeremy Dawson, NICTA *) section \Bit values as reversed lists of bools\ theory Reversed_Bit_Lists imports "HOL-Library.Word" Typedef_Morphisms begin context comm_semiring_1 begin lemma horner_sum_append: \horner_sum f a (xs @ ys) = horner_sum f a xs + a ^ length xs * horner_sum f a ys\ using sum.atLeastLessThan_shift_bounds [of _ 0 \length xs\ \length ys\] atLeastLessThan_add_Un [of 0 \length xs\ \length ys\] by (simp add: horner_sum_eq_sum sum_distrib_left sum.union_disjoint ac_simps nth_append power_add) end lemma horner_sum_of_bool_2_concat: \horner_sum of_bool 2 (concat (map (\x. map (bit x) [0.. for ws :: \'a::len word list\ proof (induction ws) case Nil then show ?case by simp next case (Cons w ws) moreover have \horner_sum of_bool 2 (map (bit w) [0.. proof transfer fix k :: int have \map (\n. n < LENGTH('a) \ bit k n) [0.. by simp then show \horner_sum of_bool 2 (map (\n. n < LENGTH('a) \ bit k n) [0.. by (simp only: horner_sum_bit_eq_take_bit) qed ultimately show ?case by (simp add: horner_sum_append) qed subsection \Implicit augmentation of list prefixes\ primrec takefill :: "'a \ nat \ 'a list \ 'a list" where Z: "takefill fill 0 xs = []" | Suc: "takefill fill (Suc n) xs = (case xs of [] \ fill # takefill fill n xs | y # ys \ y # takefill fill n ys)" lemma nth_takefill: "m < n \ takefill fill n l ! m = (if m < length l then l ! m else fill)" apply (induct n arbitrary: m l) apply clarsimp apply clarsimp apply (case_tac m) apply (simp split: list.split) apply (simp split: list.split) done lemma takefill_alt: "takefill fill n l = take n l @ replicate (n - length l) fill" by (induct n arbitrary: l) (auto split: list.split) lemma takefill_replicate [simp]: "takefill fill n (replicate m fill) = replicate n fill" by (simp add: takefill_alt replicate_add [symmetric]) lemma takefill_le': "n = m + k \ takefill x m (takefill x n l) = takefill x m l" by (induct m arbitrary: l n) (auto split: list.split) lemma length_takefill [simp]: "length (takefill fill n l) = n" by (simp add: takefill_alt) lemma take_takefill': "n = k + m \ take k (takefill fill n w) = takefill fill k w" by (induct k arbitrary: w n) (auto split: list.split) lemma drop_takefill: "drop k (takefill fill (m + k) w) = takefill fill m (drop k w)" by (induct k arbitrary: w) (auto split: list.split) lemma takefill_le [simp]: "m \ n \ takefill x m (takefill x n l) = takefill x m l" by (auto simp: le_iff_add takefill_le') lemma take_takefill [simp]: "m \ n \ take m (takefill fill n w) = takefill fill m w" by (auto simp: le_iff_add take_takefill') lemma takefill_append: "takefill fill (m + length xs) (xs @ w) = xs @ (takefill fill m w)" by (induct xs) auto lemma takefill_same': "l = length xs \ takefill fill l xs = xs" by (induct xs arbitrary: l) auto lemmas takefill_same [simp] = takefill_same' [OF refl] lemma tf_rev: "n + k = m + length bl \ takefill x m (rev (takefill y n bl)) = rev (takefill y m (rev (takefill x k (rev bl))))" apply (rule nth_equalityI) apply (auto simp add: nth_takefill rev_nth) apply (rule_tac f = "\n. bl ! n" in arg_cong) apply arith done lemma takefill_minus: "0 < n \ takefill fill (Suc (n - 1)) w = takefill fill n w" by auto lemmas takefill_Suc_cases = list.cases [THEN takefill.Suc [THEN trans]] lemmas takefill_Suc_Nil = takefill_Suc_cases (1) lemmas takefill_Suc_Cons = takefill_Suc_cases (2) lemmas takefill_minus_simps = takefill_Suc_cases [THEN [2] takefill_minus [symmetric, THEN trans]] lemma takefill_numeral_Nil [simp]: "takefill fill (numeral k) [] = fill # takefill fill (pred_numeral k) []" by (simp add: numeral_eq_Suc) lemma takefill_numeral_Cons [simp]: "takefill fill (numeral k) (x # xs) = x # takefill fill (pred_numeral k) xs" by (simp add: numeral_eq_Suc) subsection \Range projection\ definition bl_of_nth :: "nat \ (nat \ 'a) \ 'a list" where "bl_of_nth n f = map f (rev [0.. rev (bl_of_nth n f) ! m = f m" by (simp add: bl_of_nth_def rev_map) lemma bl_of_nth_inj: "(\k. k < n \ f k = g k) \ bl_of_nth n f = bl_of_nth n g" by (simp add: bl_of_nth_def) lemma bl_of_nth_nth_le: "n \ length xs \ bl_of_nth n (nth (rev xs)) = drop (length xs - n) xs" apply (induct n arbitrary: xs) apply clarsimp apply clarsimp apply (rule trans [OF _ hd_Cons_tl]) apply (frule Suc_le_lessD) apply (simp add: rev_nth trans [OF drop_Suc drop_tl, symmetric]) apply (subst hd_drop_conv_nth) apply force apply simp_all apply (rule_tac f = "\n. drop n xs" in arg_cong) apply simp done lemma bl_of_nth_nth [simp]: "bl_of_nth (length xs) ((!) (rev xs)) = xs" by (simp add: bl_of_nth_nth_le) subsection \More\ definition rotater1 :: "'a list \ 'a list" where "rotater1 ys = (case ys of [] \ [] | x # xs \ last ys # butlast ys)" definition rotater :: "nat \ 'a list \ 'a list" where "rotater n = rotater1 ^^ n" lemmas rotater_0' [simp] = rotater_def [where n = "0", simplified] lemma rotate1_rl': "rotater1 (l @ [a]) = a # l" by (cases l) (auto simp: rotater1_def) lemma rotate1_rl [simp] : "rotater1 (rotate1 l) = l" apply (unfold rotater1_def) apply (cases "l") apply (case_tac [2] "list") apply auto done lemma rotate1_lr [simp] : "rotate1 (rotater1 l) = l" by (cases l) (auto simp: rotater1_def) lemma rotater1_rev': "rotater1 (rev xs) = rev (rotate1 xs)" by (cases "xs") (simp add: rotater1_def, simp add: rotate1_rl') lemma rotater_rev': "rotater n (rev xs) = rev (rotate n xs)" by (induct n) (auto simp: rotater_def intro: rotater1_rev') lemma rotater_rev: "rotater n ys = rev (rotate n (rev ys))" using rotater_rev' [where xs = "rev ys"] by simp lemma rotater_drop_take: "rotater n xs = drop (length xs - n mod length xs) xs @ take (length xs - n mod length xs) xs" by (auto simp: rotater_rev rotate_drop_take rev_take rev_drop) lemma rotater_Suc [simp]: "rotater (Suc n) xs = rotater1 (rotater n xs)" unfolding rotater_def by auto lemma nth_rotater: \rotater m xs ! n = xs ! ((n + (length xs - m mod length xs)) mod length xs)\ if \n < length xs\ using that by (simp add: rotater_drop_take nth_append not_less less_diff_conv ac_simps le_mod_geq) lemma nth_rotater1: \rotater1 xs ! n = xs ! ((n + (length xs - 1)) mod length xs)\ if \n < length xs\ using that nth_rotater [of n xs 1] by simp lemma rotate_inv_plus [rule_format]: "\k. k = m + n \ rotater k (rotate n xs) = rotater m xs \ rotate k (rotater n xs) = rotate m xs \ rotater n (rotate k xs) = rotate m xs \ rotate n (rotater k xs) = rotater m xs" by (induct n) (auto simp: rotater_def rotate_def intro: funpow_swap1 [THEN trans]) lemmas rotate_inv_rel = le_add_diff_inverse2 [symmetric, THEN rotate_inv_plus] lemmas rotate_inv_eq = order_refl [THEN rotate_inv_rel, simplified] lemmas rotate_lr [simp] = rotate_inv_eq [THEN conjunct1] lemmas rotate_rl [simp] = rotate_inv_eq [THEN conjunct2, THEN conjunct1] lemma rotate_gal: "rotater n xs = ys \ rotate n ys = xs" by auto lemma rotate_gal': "ys = rotater n xs \ xs = rotate n ys" by auto lemma length_rotater [simp]: "length (rotater n xs) = length xs" by (simp add : rotater_rev) lemma rotate_eq_mod: "m mod length xs = n mod length xs \ rotate m xs = rotate n xs" apply (rule box_equals) defer apply (rule rotate_conv_mod [symmetric])+ apply simp done lemma restrict_to_left: "x = y \ x = z \ y = z" by simp lemmas rotate_eqs = trans [OF rotate0 [THEN fun_cong] id_apply] rotate_rotate [symmetric] rotate_id rotate_conv_mod rotate_eq_mod lemmas rrs0 = rotate_eqs [THEN restrict_to_left, simplified rotate_gal [symmetric] rotate_gal' [symmetric]] lemmas rrs1 = rrs0 [THEN refl [THEN rev_iffD1]] lemmas rotater_eqs = rrs1 [simplified length_rotater] lemmas rotater_0 = rotater_eqs (1) lemmas rotater_add = rotater_eqs (2) lemma butlast_map: "xs \ [] \ butlast (map f xs) = map f (butlast xs)" by (induct xs) auto lemma rotater1_map: "rotater1 (map f xs) = map f (rotater1 xs)" by (cases xs) (auto simp: rotater1_def last_map butlast_map) lemma rotater_map: "rotater n (map f xs) = map f (rotater n xs)" by (induct n) (auto simp: rotater_def rotater1_map) lemma but_last_zip [rule_format] : "\ys. length xs = length ys \ xs \ [] \ last (zip xs ys) = (last xs, last ys) \ butlast (zip xs ys) = zip (butlast xs) (butlast ys)" apply (induct xs) apply auto apply ((case_tac ys, auto simp: neq_Nil_conv)[1])+ done lemma but_last_map2 [rule_format] : "\ys. length xs = length ys \ xs \ [] \ last (map2 f xs ys) = f (last xs) (last ys) \ butlast (map2 f xs ys) = map2 f (butlast xs) (butlast ys)" apply (induct xs) apply auto apply ((case_tac ys, auto simp: neq_Nil_conv)[1])+ done lemma rotater1_zip: "length xs = length ys \ rotater1 (zip xs ys) = zip (rotater1 xs) (rotater1 ys)" apply (unfold rotater1_def) apply (cases xs) apply auto apply ((case_tac ys, auto simp: neq_Nil_conv but_last_zip)[1])+ done lemma rotater1_map2: "length xs = length ys \ rotater1 (map2 f xs ys) = map2 f (rotater1 xs) (rotater1 ys)" by (simp add: rotater1_map rotater1_zip) lemmas lrth = box_equals [OF asm_rl length_rotater [symmetric] length_rotater [symmetric], THEN rotater1_map2] lemma rotater_map2: "length xs = length ys \ rotater n (map2 f xs ys) = map2 f (rotater n xs) (rotater n ys)" by (induct n) (auto intro!: lrth) lemma rotate1_map2: "length xs = length ys \ rotate1 (map2 f xs ys) = map2 f (rotate1 xs) (rotate1 ys)" by (cases xs; cases ys) auto lemmas lth = box_equals [OF asm_rl length_rotate [symmetric] length_rotate [symmetric], THEN rotate1_map2] lemma rotate_map2: "length xs = length ys \ rotate n (map2 f xs ys) = map2 f (rotate n xs) (rotate n ys)" by (induct n) (auto intro!: lth) subsection \Explicit bit representation of \<^typ>\int\\ primrec bl_to_bin_aux :: "bool list \ int \ int" where Nil: "bl_to_bin_aux [] w = w" | Cons: "bl_to_bin_aux (b # bs) w = bl_to_bin_aux bs (of_bool b + 2 * w)" definition bl_to_bin :: "bool list \ int" where "bl_to_bin bs = bl_to_bin_aux bs 0" primrec bin_to_bl_aux :: "nat \ int \ bool list \ bool list" where Z: "bin_to_bl_aux 0 w bl = bl" | Suc: "bin_to_bl_aux (Suc n) w bl = bin_to_bl_aux n (bin_rest w) ((bin_last w) # bl)" definition bin_to_bl :: "nat \ int \ bool list" where "bin_to_bl n w = bin_to_bl_aux n w []" lemma bin_to_bl_aux_zero_minus_simp [simp]: "0 < n \ bin_to_bl_aux n 0 bl = bin_to_bl_aux (n - 1) 0 (False # bl)" by (cases n) auto lemma bin_to_bl_aux_minus1_minus_simp [simp]: "0 < n \ bin_to_bl_aux n (- 1) bl = bin_to_bl_aux (n - 1) (- 1) (True # bl)" by (cases n) auto lemma bin_to_bl_aux_one_minus_simp [simp]: "0 < n \ bin_to_bl_aux n 1 bl = bin_to_bl_aux (n - 1) 0 (True # bl)" by (cases n) auto lemma bin_to_bl_aux_Bit0_minus_simp [simp]: "0 < n \ bin_to_bl_aux n (numeral (Num.Bit0 w)) bl = bin_to_bl_aux (n - 1) (numeral w) (False # bl)" by (cases n) simp_all lemma bin_to_bl_aux_Bit1_minus_simp [simp]: "0 < n \ bin_to_bl_aux n (numeral (Num.Bit1 w)) bl = bin_to_bl_aux (n - 1) (numeral w) (True # bl)" by (cases n) simp_all lemma bl_to_bin_aux_append: "bl_to_bin_aux (bs @ cs) w = bl_to_bin_aux cs (bl_to_bin_aux bs w)" by (induct bs arbitrary: w) auto lemma bin_to_bl_aux_append: "bin_to_bl_aux n w bs @ cs = bin_to_bl_aux n w (bs @ cs)" by (induct n arbitrary: w bs) auto lemma bl_to_bin_append: "bl_to_bin (bs @ cs) = bl_to_bin_aux cs (bl_to_bin bs)" unfolding bl_to_bin_def by (rule bl_to_bin_aux_append) lemma bin_to_bl_aux_alt: "bin_to_bl_aux n w bs = bin_to_bl n w @ bs" by (simp add: bin_to_bl_def bin_to_bl_aux_append) lemma bin_to_bl_0 [simp]: "bin_to_bl 0 bs = []" by (auto simp: bin_to_bl_def) lemma size_bin_to_bl_aux: "length (bin_to_bl_aux n w bs) = n + length bs" by (induct n arbitrary: w bs) auto lemma size_bin_to_bl [simp]: "length (bin_to_bl n w) = n" by (simp add: bin_to_bl_def size_bin_to_bl_aux) lemma bl_bin_bl': "bin_to_bl (n + length bs) (bl_to_bin_aux bs w) = bin_to_bl_aux n w bs" apply (induct bs arbitrary: w n) apply auto apply (simp_all only: add_Suc [symmetric]) apply (auto simp add: bin_to_bl_def) done lemma bl_bin_bl [simp]: "bin_to_bl (length bs) (bl_to_bin bs) = bs" unfolding bl_to_bin_def apply (rule box_equals) apply (rule bl_bin_bl') prefer 2 apply (rule bin_to_bl_aux.Z) apply simp done lemma bl_to_bin_inj: "bl_to_bin bs = bl_to_bin cs \ length bs = length cs \ bs = cs" apply (rule_tac box_equals) defer apply (rule bl_bin_bl) apply (rule bl_bin_bl) apply simp done lemma bl_to_bin_False [simp]: "bl_to_bin (False # bl) = bl_to_bin bl" by (auto simp: bl_to_bin_def) lemma bl_to_bin_Nil [simp]: "bl_to_bin [] = 0" by (auto simp: bl_to_bin_def) lemma bin_to_bl_zero_aux: "bin_to_bl_aux n 0 bl = replicate n False @ bl" by (induct n arbitrary: bl) (auto simp: replicate_app_Cons_same) lemma bin_to_bl_zero: "bin_to_bl n 0 = replicate n False" by (simp add: bin_to_bl_def bin_to_bl_zero_aux) lemma bin_to_bl_minus1_aux: "bin_to_bl_aux n (- 1) bl = replicate n True @ bl" by (induct n arbitrary: bl) (auto simp: replicate_app_Cons_same) lemma bin_to_bl_minus1: "bin_to_bl n (- 1) = replicate n True" by (simp add: bin_to_bl_def bin_to_bl_minus1_aux) subsection \Semantic interpretation of \<^typ>\bool list\ as \<^typ>\int\\ lemma bin_bl_bin': "bl_to_bin (bin_to_bl_aux n w bs) = bl_to_bin_aux bs (bintrunc n w)" by (induct n arbitrary: w bs) (auto simp: bl_to_bin_def take_bit_Suc ac_simps mod_2_eq_odd) lemma bin_bl_bin [simp]: "bl_to_bin (bin_to_bl n w) = bintrunc n w" by (auto simp: bin_to_bl_def bin_bl_bin') lemma bl_to_bin_rep_F: "bl_to_bin (replicate n False @ bl) = bl_to_bin bl" by (simp add: bin_to_bl_zero_aux [symmetric] bin_bl_bin') (simp add: bl_to_bin_def) lemma bin_to_bl_trunc [simp]: "n \ m \ bin_to_bl n (bintrunc m w) = bin_to_bl n w" by (auto intro: bl_to_bin_inj) lemma bin_to_bl_aux_bintr: "bin_to_bl_aux n (bintrunc m bin) bl = replicate (n - m) False @ bin_to_bl_aux (min n m) bin bl" apply (induct n arbitrary: m bin bl) apply clarsimp apply clarsimp apply (case_tac "m") apply (clarsimp simp: bin_to_bl_zero_aux) apply (erule thin_rl) apply (induct_tac n) apply (auto simp add: take_bit_Suc) done lemma bin_to_bl_bintr: "bin_to_bl n (bintrunc m bin) = replicate (n - m) False @ bin_to_bl (min n m) bin" unfolding bin_to_bl_def by (rule bin_to_bl_aux_bintr) lemma bl_to_bin_rep_False: "bl_to_bin (replicate n False) = 0" by (induct n) auto lemma len_bin_to_bl_aux: "length (bin_to_bl_aux n w bs) = n + length bs" by (fact size_bin_to_bl_aux) lemma len_bin_to_bl: "length (bin_to_bl n w) = n" by (fact size_bin_to_bl) (* FIXME: duplicate *) lemma sign_bl_bin': "bin_sign (bl_to_bin_aux bs w) = bin_sign w" by (induction bs arbitrary: w) (simp_all add: bin_sign_def) lemma sign_bl_bin: "bin_sign (bl_to_bin bs) = 0" by (simp add: bl_to_bin_def sign_bl_bin') lemma bl_sbin_sign_aux: "hd (bin_to_bl_aux (Suc n) w bs) = (bin_sign (sbintrunc n w) = -1)" by (induction n arbitrary: w bs) (auto simp add: bin_sign_def even_iff_mod_2_eq_zero bit_Suc) lemma bl_sbin_sign: "hd (bin_to_bl (Suc n) w) = (bin_sign (sbintrunc n w) = -1)" unfolding bin_to_bl_def by (rule bl_sbin_sign_aux) lemma bin_nth_of_bl_aux: "bin_nth (bl_to_bin_aux bl w) n = (n < size bl \ rev bl ! n \ n \ length bl \ bin_nth w (n - size bl))" apply (induction bl arbitrary: w) apply simp_all apply safe apply (simp_all add: not_le nth_append bit_double_iff even_bit_succ_iff split: if_splits) done lemma bin_nth_of_bl: "bin_nth (bl_to_bin bl) n = (n < length bl \ rev bl ! n)" by (simp add: bl_to_bin_def bin_nth_of_bl_aux) lemma bin_nth_bl: "n < m \ bin_nth w n = nth (rev (bin_to_bl m w)) n" apply (induct n arbitrary: m w) apply clarsimp apply (case_tac m, clarsimp) apply (clarsimp simp: bin_to_bl_def) apply (simp add: bin_to_bl_aux_alt) apply (case_tac m, clarsimp) apply (clarsimp simp: bin_to_bl_def) apply (simp add: bin_to_bl_aux_alt bit_Suc) done lemma nth_bin_to_bl_aux: "n < m + length bl \ (bin_to_bl_aux m w bl) ! n = (if n < m then bit w (m - 1 - n) else bl ! (n - m))" apply (induction bl arbitrary: w) apply simp_all apply (simp add: bin_nth_bl [of \m - Suc n\ m] rev_nth flip: bin_to_bl_def) apply (metis One_nat_def Suc_pred add_diff_cancel_left' add_diff_cancel_right' bin_to_bl_aux_alt bin_to_bl_def diff_Suc_Suc diff_is_0_eq diff_zero less_Suc_eq_0_disj less_antisym less_imp_Suc_add list.size(3) nat_less_le nth_append size_bin_to_bl_aux) done lemma nth_bin_to_bl: "n < m \ (bin_to_bl m w) ! n = bin_nth w (m - Suc n)" by (simp add: bin_to_bl_def nth_bin_to_bl_aux) lemma takefill_bintrunc: "takefill False n bl = rev (bin_to_bl n (bl_to_bin (rev bl)))" apply (rule nth_equalityI) apply simp apply (clarsimp simp: nth_takefill rev_nth nth_bin_to_bl bin_nth_of_bl) done lemma bl_bin_bl_rtf: "bin_to_bl n (bl_to_bin bl) = rev (takefill False n (rev bl))" by (simp add: takefill_bintrunc) lemma bl_to_bin_lt2p_aux: "bl_to_bin_aux bs w < (w + 1) * (2 ^ length bs)" proof (induction bs arbitrary: w) case Nil then show ?case by simp next case (Cons b bs) from Cons.IH [of \1 + 2 * w\] Cons.IH [of \2 * w\] show ?case apply (auto simp add: algebra_simps) apply (subst mult_2 [of \2 ^ length bs\]) apply (simp only: add.assoc) apply (rule pos_add_strict) apply simp_all done qed lemma bl_to_bin_lt2p_drop: "bl_to_bin bs < 2 ^ length (dropWhile Not bs)" proof (induct bs) case Nil then show ?case by simp next case (Cons b bs) with bl_to_bin_lt2p_aux[where w=1] show ?case by (simp add: bl_to_bin_def) qed lemma bl_to_bin_lt2p: "bl_to_bin bs < 2 ^ length bs" by (metis bin_bl_bin bintr_lt2p bl_bin_bl) lemma bl_to_bin_ge2p_aux: "bl_to_bin_aux bs w \ w * (2 ^ length bs)" proof (induction bs arbitrary: w) case Nil then show ?case by simp next case (Cons b bs) from Cons.IH [of \1 + 2 * w\] Cons.IH [of \2 * w\] show ?case apply (auto simp add: algebra_simps) apply (rule add_le_imp_le_left [of \2 ^ length bs\]) apply (rule add_increasing) apply simp_all done qed lemma bl_to_bin_ge0: "bl_to_bin bs \ 0" apply (unfold bl_to_bin_def) apply (rule xtrans(4)) apply (rule bl_to_bin_ge2p_aux) apply simp done lemma butlast_rest_bin: "butlast (bin_to_bl n w) = bin_to_bl (n - 1) (bin_rest w)" apply (unfold bin_to_bl_def) apply (cases n, clarsimp) apply clarsimp apply (auto simp add: bin_to_bl_aux_alt) done lemma butlast_bin_rest: "butlast bl = bin_to_bl (length bl - Suc 0) (bin_rest (bl_to_bin bl))" using butlast_rest_bin [where w="bl_to_bin bl" and n="length bl"] by simp lemma butlast_rest_bl2bin_aux: "bl \ [] \ bl_to_bin_aux (butlast bl) w = bin_rest (bl_to_bin_aux bl w)" by (induct bl arbitrary: w) auto lemma butlast_rest_bl2bin: "bl_to_bin (butlast bl) = bin_rest (bl_to_bin bl)" by (cases bl) (auto simp: bl_to_bin_def butlast_rest_bl2bin_aux) lemma trunc_bl2bin_aux: "bintrunc m (bl_to_bin_aux bl w) = bl_to_bin_aux (drop (length bl - m) bl) (bintrunc (m - length bl) w)" proof (induct bl arbitrary: w) case Nil show ?case by simp next case (Cons b bl) show ?case proof (cases "m - length bl") case 0 then have "Suc (length bl) - m = Suc (length bl - m)" by simp with Cons show ?thesis by simp next case (Suc n) then have "m - Suc (length bl) = n" by simp with Cons Suc show ?thesis by (simp add: take_bit_Suc ac_simps) qed qed lemma trunc_bl2bin: "bintrunc m (bl_to_bin bl) = bl_to_bin (drop (length bl - m) bl)" by (simp add: bl_to_bin_def trunc_bl2bin_aux) lemma trunc_bl2bin_len [simp]: "bintrunc (length bl) (bl_to_bin bl) = bl_to_bin bl" by (simp add: trunc_bl2bin) lemma bl2bin_drop: "bl_to_bin (drop k bl) = bintrunc (length bl - k) (bl_to_bin bl)" apply (rule trans) prefer 2 apply (rule trunc_bl2bin [symmetric]) apply (cases "k \ length bl") apply auto done lemma take_rest_power_bin: "m \ n \ take m (bin_to_bl n w) = bin_to_bl m ((bin_rest ^^ (n - m)) w)" apply (rule nth_equalityI) apply simp apply (clarsimp simp add: nth_bin_to_bl nth_rest_power_bin) done lemma last_bin_last': "size xs > 0 \ last xs \ bin_last (bl_to_bin_aux xs w)" by (induct xs arbitrary: w) auto lemma last_bin_last: "size xs > 0 \ last xs \ bin_last (bl_to_bin xs)" unfolding bl_to_bin_def by (erule last_bin_last') lemma bin_last_last: "bin_last w \ last (bin_to_bl (Suc n) w)" by (simp add: bin_to_bl_def) (auto simp: bin_to_bl_aux_alt) lemma drop_bin2bl_aux: "drop m (bin_to_bl_aux n bin bs) = bin_to_bl_aux (n - m) bin (drop (m - n) bs)" apply (induction n arbitrary: m bin bs) apply auto apply (case_tac "m \ n") apply (auto simp add: not_le Suc_diff_le) apply (case_tac "m - n") apply auto apply (use Suc_diff_Suc in fastforce) done lemma drop_bin2bl: "drop m (bin_to_bl n bin) = bin_to_bl (n - m) bin" by (simp add: bin_to_bl_def drop_bin2bl_aux) lemma take_bin2bl_lem1: "take m (bin_to_bl_aux m w bs) = bin_to_bl m w" apply (induct m arbitrary: w bs) apply clarsimp apply clarsimp apply (simp add: bin_to_bl_aux_alt) apply (simp add: bin_to_bl_def) apply (simp add: bin_to_bl_aux_alt) done lemma take_bin2bl_lem: "take m (bin_to_bl_aux (m + n) w bs) = take m (bin_to_bl (m + n) w)" by (induct n arbitrary: w bs) (simp_all (no_asm) add: bin_to_bl_def take_bin2bl_lem1, simp) lemma bin_split_take: "bin_split n c = (a, b) \ bin_to_bl m a = take m (bin_to_bl (m + n) c)" apply (induct n arbitrary: b c) apply clarsimp apply (clarsimp simp: Let_def split: prod.split_asm) apply (simp add: bin_to_bl_def) apply (simp add: take_bin2bl_lem drop_bit_Suc) done lemma bin_to_bl_drop_bit: "k = m + n \ bin_to_bl m (drop_bit n c) = take m (bin_to_bl k c)" using bin_split_take by simp lemma bin_split_take1: "k = m + n \ bin_split n c = (a, b) \ bin_to_bl m a = take m (bin_to_bl k c)" using bin_split_take by simp lemma bl_bin_bl_rep_drop: "bin_to_bl n (bl_to_bin bl) = replicate (n - length bl) False @ drop (length bl - n) bl" by (simp add: bl_to_bin_inj bl_to_bin_rep_F trunc_bl2bin) lemma bl_to_bin_aux_cat: "bl_to_bin_aux bs (bin_cat w nv v) = bin_cat w (nv + length bs) (bl_to_bin_aux bs v)" by (rule bit_eqI) (auto simp add: bin_nth_of_bl_aux bin_nth_cat algebra_simps) lemma bin_to_bl_aux_cat: "bin_to_bl_aux (nv + nw) (bin_cat v nw w) bs = bin_to_bl_aux nv v (bin_to_bl_aux nw w bs)" by (induction nw arbitrary: w bs) (simp_all add: concat_bit_Suc) lemma bl_to_bin_aux_alt: "bl_to_bin_aux bs w = bin_cat w (length bs) (bl_to_bin bs)" using bl_to_bin_aux_cat [where nv = "0" and v = "0"] by (simp add: bl_to_bin_def [symmetric]) lemma bin_to_bl_cat: "bin_to_bl (nv + nw) (bin_cat v nw w) = bin_to_bl_aux nv v (bin_to_bl nw w)" by (simp add: bin_to_bl_def bin_to_bl_aux_cat) lemmas bl_to_bin_aux_app_cat = trans [OF bl_to_bin_aux_append bl_to_bin_aux_alt] lemmas bin_to_bl_aux_cat_app = trans [OF bin_to_bl_aux_cat bin_to_bl_aux_alt] lemma bl_to_bin_app_cat: "bl_to_bin (bsa @ bs) = bin_cat (bl_to_bin bsa) (length bs) (bl_to_bin bs)" by (simp only: bl_to_bin_aux_app_cat bl_to_bin_def) lemma bin_to_bl_cat_app: "bin_to_bl (n + nw) (bin_cat w nw wa) = bin_to_bl n w @ bin_to_bl nw wa" by (simp only: bin_to_bl_def bin_to_bl_aux_cat_app) text \\bl_to_bin_app_cat_alt\ and \bl_to_bin_app_cat\ are easily interderivable.\ lemma bl_to_bin_app_cat_alt: "bin_cat (bl_to_bin cs) n w = bl_to_bin (cs @ bin_to_bl n w)" by (simp add: bl_to_bin_app_cat) lemma mask_lem: "(bl_to_bin (True # replicate n False)) = bl_to_bin (replicate n True) + 1" apply (unfold bl_to_bin_def) apply (induct n) apply simp apply (simp only: Suc_eq_plus1 replicate_add append_Cons [symmetric] bl_to_bin_aux_append) apply simp done lemma bin_exhaust: "(\x b. bin = of_bool b + 2 * x \ Q) \ Q" for bin :: int apply (cases \even bin\) apply (auto elim!: evenE oddE) apply fastforce apply fastforce done primrec rbl_succ :: "bool list \ bool list" where Nil: "rbl_succ Nil = Nil" | Cons: "rbl_succ (x # xs) = (if x then False # rbl_succ xs else True # xs)" primrec rbl_pred :: "bool list \ bool list" where Nil: "rbl_pred Nil = Nil" | Cons: "rbl_pred (x # xs) = (if x then False # xs else True # rbl_pred xs)" primrec rbl_add :: "bool list \ bool list \ bool list" where \ \result is length of first arg, second arg may be longer\ Nil: "rbl_add Nil x = Nil" | Cons: "rbl_add (y # ys) x = (let ws = rbl_add ys (tl x) in (y \ hd x) # (if hd x \ y then rbl_succ ws else ws))" primrec rbl_mult :: "bool list \ bool list \ bool list" where \ \result is length of first arg, second arg may be longer\ Nil: "rbl_mult Nil x = Nil" | Cons: "rbl_mult (y # ys) x = (let ws = False # rbl_mult ys x in if y then rbl_add ws x else ws)" lemma size_rbl_pred: "length (rbl_pred bl) = length bl" by (induct bl) auto lemma size_rbl_succ: "length (rbl_succ bl) = length bl" by (induct bl) auto lemma size_rbl_add: "length (rbl_add bl cl) = length bl" by (induct bl arbitrary: cl) (auto simp: Let_def size_rbl_succ) lemma size_rbl_mult: "length (rbl_mult bl cl) = length bl" by (induct bl arbitrary: cl) (auto simp add: Let_def size_rbl_add) lemmas rbl_sizes [simp] = size_rbl_pred size_rbl_succ size_rbl_add size_rbl_mult lemmas rbl_Nils = rbl_pred.Nil rbl_succ.Nil rbl_add.Nil rbl_mult.Nil lemma rbl_add_app2: "length blb \ length bla \ rbl_add bla (blb @ blc) = rbl_add bla blb" apply (induct bla arbitrary: blb) apply simp apply clarsimp apply (case_tac blb, clarsimp) apply (clarsimp simp: Let_def) done lemma rbl_add_take2: "length blb \ length bla \ rbl_add bla (take (length bla) blb) = rbl_add bla blb" apply (induct bla arbitrary: blb) apply simp apply clarsimp apply (case_tac blb, clarsimp) apply (clarsimp simp: Let_def) done lemma rbl_mult_app2: "length blb \ length bla \ rbl_mult bla (blb @ blc) = rbl_mult bla blb" apply (induct bla arbitrary: blb) apply simp apply clarsimp apply (case_tac blb, clarsimp) apply (clarsimp simp: Let_def rbl_add_app2) done lemma rbl_mult_take2: "length blb \ length bla \ rbl_mult bla (take (length bla) blb) = rbl_mult bla blb" apply (rule trans) apply (rule rbl_mult_app2 [symmetric]) apply simp apply (rule_tac f = "rbl_mult bla" in arg_cong) apply (rule append_take_drop_id) done lemma rbl_add_split: "P (rbl_add (y # ys) (x # xs)) = (\ws. length ws = length ys \ ws = rbl_add ys xs \ (y \ ((x \ P (False # rbl_succ ws)) \ (\ x \ P (True # ws)))) \ (\ y \ P (x # ws)))" by (cases y) (auto simp: Let_def) lemma rbl_mult_split: "P (rbl_mult (y # ys) xs) = (\ws. length ws = Suc (length ys) \ ws = False # rbl_mult ys xs \ (y \ P (rbl_add ws xs)) \ (\ y \ P ws))" by (auto simp: Let_def) lemma rbl_pred: "rbl_pred (rev (bin_to_bl n bin)) = rev (bin_to_bl n (bin - 1))" proof (unfold bin_to_bl_def, induction n arbitrary: bin) case 0 then show ?case by simp next case (Suc n) obtain b k where \bin = of_bool b + 2 * k\ using bin_exhaust by blast moreover have \(2 * k - 1) div 2 = k - 1\ using even_succ_div_2 [of \2 * (k - 1)\] by simp ultimately show ?case using Suc [of \bin div 2\] by simp (simp add: bin_to_bl_aux_alt) qed lemma rbl_succ: "rbl_succ (rev (bin_to_bl n bin)) = rev (bin_to_bl n (bin + 1))" apply (unfold bin_to_bl_def) apply (induction n arbitrary: bin) apply simp_all apply (case_tac bin rule: bin_exhaust) apply simp apply (simp add: bin_to_bl_aux_alt ac_simps) done lemma rbl_add: "\bina binb. rbl_add (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb)) = rev (bin_to_bl n (bina + binb))" apply (unfold bin_to_bl_def) apply (induct n) apply simp apply clarsimp apply (case_tac bina rule: bin_exhaust) apply (case_tac binb rule: bin_exhaust) apply (case_tac b) apply (case_tac [!] "ba") apply (auto simp: rbl_succ bin_to_bl_aux_alt Let_def ac_simps) done lemma rbl_add_long: "m \ n \ rbl_add (rev (bin_to_bl n bina)) (rev (bin_to_bl m binb)) = rev (bin_to_bl n (bina + binb))" apply (rule box_equals [OF _ rbl_add_take2 rbl_add]) apply (rule_tac f = "rbl_add (rev (bin_to_bl n bina))" in arg_cong) apply (rule rev_swap [THEN iffD1]) apply (simp add: rev_take drop_bin2bl) apply simp done lemma rbl_mult_gt1: "m \ length bl \ rbl_mult bl (rev (bin_to_bl m binb)) = rbl_mult bl (rev (bin_to_bl (length bl) binb))" apply (rule trans) apply (rule rbl_mult_take2 [symmetric]) apply simp_all apply (rule_tac f = "rbl_mult bl" in arg_cong) apply (rule rev_swap [THEN iffD1]) apply (simp add: rev_take drop_bin2bl) done lemma rbl_mult_gt: "m > n \ rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl m binb)) = rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb))" by (auto intro: trans [OF rbl_mult_gt1]) lemmas rbl_mult_Suc = lessI [THEN rbl_mult_gt] lemma rbbl_Cons: "b # rev (bin_to_bl n x) = rev (bin_to_bl (Suc n) (of_bool b + 2 * x))" by (simp add: bin_to_bl_def) (simp add: bin_to_bl_aux_alt) lemma rbl_mult: "rbl_mult (rev (bin_to_bl n bina)) (rev (bin_to_bl n binb)) = rev (bin_to_bl n (bina * binb))" apply (induct n arbitrary: bina binb) apply simp_all apply (unfold bin_to_bl_def) apply clarsimp apply (case_tac bina rule: bin_exhaust) apply (case_tac binb rule: bin_exhaust) apply simp apply (simp add: bin_to_bl_aux_alt) apply (simp add: rbbl_Cons rbl_mult_Suc rbl_add algebra_simps) done lemma sclem: "size (concat (map (bin_to_bl n) xs)) = length xs * n" by (induct xs) auto lemma bin_cat_foldl_lem: "foldl (\u. bin_cat u n) x xs = bin_cat x (size xs * n) (foldl (\u. bin_cat u n) y xs)" apply (induct xs arbitrary: x) apply simp apply (simp (no_asm)) apply (frule asm_rl) apply (drule meta_spec) apply (erule trans) apply (drule_tac x = "bin_cat y n a" in meta_spec) apply (simp add: bin_cat_assoc_sym min.absorb2) done lemma bin_rcat_bl: "bin_rcat n wl = bl_to_bin (concat (map (bin_to_bl n) wl))" apply (unfold bin_rcat_eq_foldl) apply (rule sym) apply (induct wl) apply (auto simp add: bl_to_bin_append) apply (simp add: bl_to_bin_aux_alt sclem) apply (simp add: bin_cat_foldl_lem [symmetric]) done lemma bin_last_bl_to_bin: "bin_last (bl_to_bin bs) \ bs \ [] \ last bs" by(cases "bs = []")(auto simp add: bl_to_bin_def last_bin_last'[where w=0]) lemma bin_rest_bl_to_bin: "bin_rest (bl_to_bin bs) = bl_to_bin (butlast bs)" by(cases "bs = []")(simp_all add: bl_to_bin_def butlast_rest_bl2bin_aux) lemma bl_xor_aux_bin: "map2 (\x y. x \ y) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v XOR w) (map2 (\x y. x \ y) bs cs)" apply (induction n arbitrary: v w bs cs) apply auto apply (case_tac v rule: bin_exhaust) apply (case_tac w rule: bin_exhaust) apply clarsimp done lemma bl_or_aux_bin: "map2 (\) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v OR w) (map2 (\) bs cs)" by (induct n arbitrary: v w bs cs) simp_all lemma bl_and_aux_bin: "map2 (\) (bin_to_bl_aux n v bs) (bin_to_bl_aux n w cs) = bin_to_bl_aux n (v AND w) (map2 (\) bs cs)" by (induction n arbitrary: v w bs cs) simp_all lemma bl_not_aux_bin: "map Not (bin_to_bl_aux n w cs) = bin_to_bl_aux n (NOT w) (map Not cs)" by (induct n arbitrary: w cs) auto lemma bl_not_bin: "map Not (bin_to_bl n w) = bin_to_bl n (NOT w)" by (simp add: bin_to_bl_def bl_not_aux_bin) lemma bl_and_bin: "map2 (\) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v AND w)" by (simp add: bin_to_bl_def bl_and_aux_bin) lemma bl_or_bin: "map2 (\) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v OR w)" by (simp add: bin_to_bl_def bl_or_aux_bin) lemma bl_xor_bin: "map2 (\) (bin_to_bl n v) (bin_to_bl n w) = bin_to_bl n (v XOR w)" using bl_xor_aux_bin by (simp add: bin_to_bl_def) subsection \Type \<^typ>\'a word\\ lift_definition of_bl :: \bool list \ 'a::len word\ is bl_to_bin . lift_definition to_bl :: \'a::len word \ bool list\ is \bin_to_bl LENGTH('a)\ by (simp add: bl_to_bin_inj) lemma to_bl_eq: \to_bl w = bin_to_bl (LENGTH('a)) (uint w)\ for w :: \'a::len word\ by transfer simp -lemma bit_of_bl_iff: +lemma bit_of_bl_iff [bit_simps]: \bit (of_bl bs :: 'a word) n \ rev bs ! n \ n < LENGTH('a::len) \ n < length bs\ by transfer (simp add: bin_nth_of_bl ac_simps) lemma rev_to_bl_eq: \rev (to_bl w) = map (bit w) [0.. for w :: \'a::len word\ apply (rule nth_equalityI) apply (simp add: to_bl.rep_eq) apply (simp add: bin_nth_bl bit_word.rep_eq to_bl.rep_eq) done lemma to_bl_eq_rev: \to_bl w = map (bit w) (rev [0.. for w :: \'a::len word\ using rev_to_bl_eq [of w] apply (subst rev_is_rev_conv [symmetric]) apply (simp add: rev_map) done lemma of_bl_rev_eq: \of_bl (rev bs) = horner_sum of_bool 2 bs\ apply (rule bit_word_eqI) apply (simp add: bit_of_bl_iff) apply transfer apply (simp add: bit_horner_sum_bit_iff ac_simps) done lemma of_bl_eq: \of_bl bs = horner_sum of_bool 2 (rev bs)\ using of_bl_rev_eq [of \rev bs\] by simp lemma bshiftr1_eq: \bshiftr1 b w = of_bl (b # butlast (to_bl w))\ apply transfer apply auto apply (subst bl_to_bin_app_cat [of \[True]\, simplified]) apply simp apply (metis One_nat_def add.commute bin_bl_bin bin_last_bl_to_bin bin_rest_bl_to_bin butlast_bin_rest concat_bit_eq last.simps list.distinct(1) list.size(3) list.size(4) odd_iff_mod_2_eq_one plus_1_eq_Suc power_Suc0_right push_bit_of_1 size_bin_to_bl take_bit_eq_mod trunc_bl2bin_len) apply (simp add: butlast_rest_bl2bin) done lemma length_to_bl_eq: \length (to_bl w) = LENGTH('a)\ for w :: \'a::len word\ by transfer simp lemma word_rotr_eq: \word_rotr n w = of_bl (rotater n (to_bl w))\ apply (rule bit_word_eqI) subgoal for n apply (cases \n < LENGTH('a)\) apply (simp_all add: bit_word_rotr_iff bit_of_bl_iff rotater_rev length_to_bl_eq nth_rotate rev_to_bl_eq ac_simps) done done lemma word_rotl_eq: \word_rotl n w = of_bl (rotate n (to_bl w))\ proof - have \rotate n (to_bl w) = rev (rotater n (rev (to_bl w)))\ by (simp add: rotater_rev') then show ?thesis apply (simp add: word_rotl_eq_word_rotr bit_of_bl_iff length_to_bl_eq rev_to_bl_eq) apply (rule bit_word_eqI) subgoal for n apply (cases \n < LENGTH('a)\) apply (simp_all add: bit_word_rotr_iff bit_of_bl_iff nth_rotater) done done qed lemma to_bl_def': "(to_bl :: 'a::len word \ bool list) = bin_to_bl (LENGTH('a)) \ uint" by transfer (simp add: fun_eq_iff) \ \type definitions theorem for in terms of equivalent bool list\ lemma td_bl: "type_definition (to_bl :: 'a::len word \ bool list) of_bl {bl. length bl = LENGTH('a)}" apply (standard; transfer) apply (auto dest: sym) done interpretation word_bl: type_definition "to_bl :: 'a::len word \ bool list" of_bl "{bl. length bl = LENGTH('a::len)}" by (fact td_bl) lemmas word_bl_Rep' = word_bl.Rep [unfolded mem_Collect_eq, iff] lemma word_size_bl: "size w = size (to_bl w)" by (auto simp: word_size) lemma to_bl_use_of_bl: "to_bl w = bl \ w = of_bl bl \ length bl = length (to_bl w)" by (fastforce elim!: word_bl.Abs_inverse [unfolded mem_Collect_eq]) lemma length_bl_gt_0 [iff]: "0 < length (to_bl x)" for x :: "'a::len word" unfolding word_bl_Rep' by (rule len_gt_0) lemma bl_not_Nil [iff]: "to_bl x \ []" for x :: "'a::len word" by (fact length_bl_gt_0 [unfolded length_greater_0_conv]) lemma length_bl_neq_0 [iff]: "length (to_bl x) \ 0" for x :: "'a::len word" by (fact length_bl_gt_0 [THEN gr_implies_not0]) lemma hd_bl_sign_sint: "hd (to_bl w) = (bin_sign (sint w) = -1)" apply transfer apply (auto simp add: bin_sign_def) using bin_sign_lem bl_sbin_sign apply fastforce using bin_sign_lem bl_sbin_sign apply force done lemma of_bl_drop': "lend = length bl - LENGTH('a::len) \ of_bl (drop lend bl) = (of_bl bl :: 'a word)" by transfer (simp flip: trunc_bl2bin) lemma test_bit_of_bl: "(of_bl bl::'a::len word) !! n = (rev bl ! n \ n < LENGTH('a) \ n < length bl)" by transfer (simp add: bin_nth_of_bl ac_simps) lemma no_of_bl: "(numeral bin ::'a::len word) = of_bl (bin_to_bl (LENGTH('a)) (numeral bin))" by transfer simp lemma uint_bl: "to_bl w = bin_to_bl (size w) (uint w)" by transfer simp lemma to_bl_bin: "bl_to_bin (to_bl w) = uint w" by (simp add: uint_bl word_size) lemma to_bl_of_bin: "to_bl (word_of_int bin::'a::len word) = bin_to_bl (LENGTH('a)) bin" by (auto simp: uint_bl word_ubin.eq_norm word_size) lemma to_bl_numeral [simp]: "to_bl (numeral bin::'a::len word) = bin_to_bl (LENGTH('a)) (numeral bin)" unfolding word_numeral_alt by (rule to_bl_of_bin) lemma to_bl_neg_numeral [simp]: "to_bl (- numeral bin::'a::len word) = bin_to_bl (LENGTH('a)) (- numeral bin)" unfolding word_neg_numeral_alt by (rule to_bl_of_bin) lemma to_bl_to_bin [simp] : "bl_to_bin (to_bl w) = uint w" by (simp add: uint_bl word_size) lemma uint_bl_bin: "bl_to_bin (bin_to_bl (LENGTH('a)) (uint x)) = uint x" for x :: "'a::len word" by (rule trans [OF bin_bl_bin word_ubin.norm_Rep]) lemma ucast_bl: "ucast w = of_bl (to_bl w)" by transfer simp lemma ucast_down_bl: \(ucast :: 'a::len word \ 'b::len word) (of_bl bl) = of_bl bl\ if \is_down (ucast :: 'a::len word \ 'b::len word)\ using that by transfer simp lemma of_bl_append_same: "of_bl (X @ to_bl w) = w" by transfer (simp add: bl_to_bin_app_cat) lemma ucast_of_bl_up: \ucast (of_bl bl :: 'a::len word) = of_bl bl\ if \size bl \ size (of_bl bl :: 'a::len word)\ using that apply transfer apply (rule bit_eqI) apply (auto simp add: bit_take_bit_iff) apply (subst (asm) trunc_bl2bin_len [symmetric]) apply (auto simp only: bit_take_bit_iff) done lemma word_rev_tf: "to_bl (of_bl bl::'a::len word) = rev (takefill False (LENGTH('a)) (rev bl))" by transfer (simp add: bl_bin_bl_rtf) lemma word_rep_drop: "to_bl (of_bl bl::'a::len word) = replicate (LENGTH('a) - length bl) False @ drop (length bl - LENGTH('a)) bl" by (simp add: word_rev_tf takefill_alt rev_take) lemma to_bl_ucast: "to_bl (ucast (w::'b::len word) ::'a::len word) = replicate (LENGTH('a) - LENGTH('b)) False @ drop (LENGTH('b) - LENGTH('a)) (to_bl w)" apply (unfold ucast_bl) apply (rule trans) apply (rule word_rep_drop) apply simp done lemma ucast_up_app: \to_bl (ucast w :: 'b::len word) = replicate n False @ (to_bl w)\ if \source_size (ucast :: 'a word \ 'b word) + n = target_size (ucast :: 'a word \ 'b word)\ for w :: \'a::len word\ using that by (auto simp add : source_size target_size to_bl_ucast) lemma ucast_down_drop [OF refl]: "uc = ucast \ source_size uc = target_size uc + n \ to_bl (uc w) = drop n (to_bl w)" by (auto simp add : source_size target_size to_bl_ucast) lemma scast_down_drop [OF refl]: "sc = scast \ source_size sc = target_size sc + n \ to_bl (sc w) = drop n (to_bl w)" apply (subgoal_tac "sc = ucast") apply safe apply simp apply (erule ucast_down_drop) apply (rule down_cast_same [symmetric]) apply (simp add : source_size target_size is_down) done lemma word_0_bl [simp]: "of_bl [] = 0" by transfer simp lemma word_1_bl: "of_bl [True] = 1" by transfer (simp add: bl_to_bin_def) lemma of_bl_0 [simp]: "of_bl (replicate n False) = 0" by transfer (simp add: bl_to_bin_rep_False) lemma to_bl_0 [simp]: "to_bl (0::'a::len word) = replicate (LENGTH('a)) False" by (simp add: uint_bl word_size bin_to_bl_zero) \ \links with \rbl\ operations\ lemma word_succ_rbl: "to_bl w = bl \ to_bl (word_succ w) = rev (rbl_succ (rev bl))" by transfer (simp add: rbl_succ) lemma word_pred_rbl: "to_bl w = bl \ to_bl (word_pred w) = rev (rbl_pred (rev bl))" by transfer (simp add: rbl_pred) lemma word_add_rbl: "to_bl v = vbl \ to_bl w = wbl \ to_bl (v + w) = rev (rbl_add (rev vbl) (rev wbl))" apply transfer apply (drule sym) apply (drule sym) apply (simp add: rbl_add) done lemma word_mult_rbl: "to_bl v = vbl \ to_bl w = wbl \ to_bl (v * w) = rev (rbl_mult (rev vbl) (rev wbl))" apply transfer apply (drule sym) apply (drule sym) apply (simp add: rbl_mult) done lemma rtb_rbl_ariths: "rev (to_bl w) = ys \ rev (to_bl (word_succ w)) = rbl_succ ys" "rev (to_bl w) = ys \ rev (to_bl (word_pred w)) = rbl_pred ys" "rev (to_bl v) = ys \ rev (to_bl w) = xs \ rev (to_bl (v * w)) = rbl_mult ys xs" "rev (to_bl v) = ys \ rev (to_bl w) = xs \ rev (to_bl (v + w)) = rbl_add ys xs" by (auto simp: rev_swap [symmetric] word_succ_rbl word_pred_rbl word_mult_rbl word_add_rbl) lemma of_bl_length_less: \(of_bl x :: 'a::len word) < 2 ^ k\ if \length x = k\ \k < LENGTH('a)\ proof - from that have \length x < LENGTH('a)\ by simp then have \(of_bl x :: 'a::len word) < 2 ^ length x\ apply (simp add: of_bl_eq) apply transfer apply (simp add: take_bit_horner_sum_bit_eq) apply (subst length_rev [symmetric]) apply (simp only: horner_sum_of_bool_2_less) done with that show ?thesis by simp qed lemma word_eq_rbl_eq: "x = y \ rev (to_bl x) = rev (to_bl y)" by simp lemma bl_word_not: "to_bl (NOT w) = map Not (to_bl w)" by transfer (simp add: bl_not_bin) lemma bl_word_xor: "to_bl (v XOR w) = map2 (\) (to_bl v) (to_bl w)" by transfer (simp flip: bl_xor_bin) lemma bl_word_or: "to_bl (v OR w) = map2 (\) (to_bl v) (to_bl w)" by transfer (simp flip: bl_or_bin) lemma bl_word_and: "to_bl (v AND w) = map2 (\) (to_bl v) (to_bl w)" by transfer (simp flip: bl_and_bin) lemma bin_nth_uint': "bin_nth (uint w) n \ rev (bin_to_bl (size w) (uint w)) ! n \ n < size w" apply (unfold word_size) apply (safe elim!: bin_nth_uint_imp) apply (frule bin_nth_uint_imp) apply (fast dest!: bin_nth_bl)+ done lemmas bin_nth_uint = bin_nth_uint' [unfolded word_size] lemma test_bit_bl: "w !! n \ rev (to_bl w) ! n \ n < size w" by transfer (auto simp add: bin_nth_bl) lemma to_bl_nth: "n < size w \ to_bl w ! n = w !! (size w - Suc n)" by (simp add: word_size rev_nth test_bit_bl) lemma map_bit_interval_eq: \map (bit w) [0.. for w :: \'a::len word\ proof (rule nth_equalityI) show \length (map (bit w) [0.. by simp fix m assume \m < length (map (bit w) [0.. then have \m < n\ by simp then have \bit w m \ takefill False n (rev (to_bl w)) ! m\ by (auto simp add: nth_takefill not_less rev_nth to_bl_nth word_size test_bit_word_eq dest: bit_imp_le_length) with \m < n \show \map (bit w) [0.. takefill False n (rev (to_bl w)) ! m\ by simp qed lemma to_bl_unfold: \to_bl w = rev (map (bit w) [0.. for w :: \'a::len word\ by (simp add: map_bit_interval_eq takefill_bintrunc to_bl_def flip: bin_to_bl_def) lemma nth_rev_to_bl: \rev (to_bl w) ! n \ bit w n\ if \n < LENGTH('a)\ for w :: \'a::len word\ using that by (simp add: to_bl_unfold) lemma nth_to_bl: \to_bl w ! n \ bit w (LENGTH('a) - Suc n)\ if \n < LENGTH('a)\ for w :: \'a::len word\ using that by (simp add: to_bl_unfold rev_nth) lemma of_bl_rep_False: "of_bl (replicate n False @ bs) = of_bl bs" by (auto simp: of_bl_def bl_to_bin_rep_F) lemma [code abstract]: \uint (of_bl bs :: 'a word) = horner_sum of_bool 2 (take LENGTH('a::len) (rev bs))\ apply (simp add: of_bl_eq flip: take_bit_horner_sum_bit_eq) apply transfer apply simp done lemma [code]: \to_bl w = map (bit w) (rev [0.. for w :: \'a::len word\ by (simp add: to_bl_unfold rev_map) lemma word_reverse_eq_of_bl_rev_to_bl: \word_reverse w = of_bl (rev (to_bl w))\ by (rule bit_word_eqI) (auto simp add: bit_word_reverse_iff bit_of_bl_iff nth_to_bl) lemmas word_reverse_no_def [simp] = word_reverse_eq_of_bl_rev_to_bl [of "numeral w"] for w lemma to_bl_word_rev: "to_bl (word_reverse w) = rev (to_bl w)" by (rule nth_equalityI) (simp_all add: nth_rev_to_bl word_reverse_def word_rep_drop flip: of_bl_eq) lemma to_bl_n1 [simp]: "to_bl (-1::'a::len word) = replicate (LENGTH('a)) True" apply (rule word_bl.Abs_inverse') apply simp apply (rule word_eqI) apply (clarsimp simp add: word_size) apply (auto simp add: word_bl.Abs_inverse test_bit_bl word_size) done lemma rbl_word_or: "rev (to_bl (x OR y)) = map2 (\) (rev (to_bl x)) (rev (to_bl y))" by (simp add: zip_rev bl_word_or rev_map) lemma rbl_word_and: "rev (to_bl (x AND y)) = map2 (\) (rev (to_bl x)) (rev (to_bl y))" by (simp add: zip_rev bl_word_and rev_map) lemma rbl_word_xor: "rev (to_bl (x XOR y)) = map2 (\) (rev (to_bl x)) (rev (to_bl y))" by (simp add: zip_rev bl_word_xor rev_map) lemma rbl_word_not: "rev (to_bl (NOT x)) = map Not (rev (to_bl x))" by (simp add: bl_word_not rev_map) lemma bshiftr1_numeral [simp]: \bshiftr1 b (numeral w :: 'a word) = of_bl (b # butlast (bin_to_bl LENGTH('a::len) (numeral w)))\ by (simp add: bshiftr1_eq) lemma bshiftr1_bl: "to_bl (bshiftr1 b w) = b # butlast (to_bl w)" unfolding bshiftr1_eq by (rule word_bl.Abs_inverse) simp lemma shiftl1_of_bl: "shiftl1 (of_bl bl) = of_bl (bl @ [False])" by transfer (simp add: bl_to_bin_append) lemma shiftl1_bl: "shiftl1 w = of_bl (to_bl w @ [False])" for w :: "'a::len word" proof - have "shiftl1 w = shiftl1 (of_bl (to_bl w))" by simp also have "\ = of_bl (to_bl w @ [False])" by (rule shiftl1_of_bl) finally show ?thesis . qed lemma bl_shiftl1: "to_bl (shiftl1 w) = tl (to_bl w) @ [False]" for w :: "'a::len word" by (simp add: shiftl1_bl word_rep_drop drop_Suc drop_Cons') (fast intro!: Suc_leI) \ \Generalized version of \bl_shiftl1\. Maybe this one should replace it?\ lemma bl_shiftl1': "to_bl (shiftl1 w) = tl (to_bl w @ [False])" by (simp add: shiftl1_bl word_rep_drop drop_Suc del: drop_append) lemma shiftr1_bl: \shiftr1 w = of_bl (butlast (to_bl w))\ proof (rule bit_word_eqI) fix n assume \n < LENGTH('a)\ show \bit (shiftr1 w) n \ bit (of_bl (butlast (to_bl w)) :: 'a word) n\ proof (cases \n = LENGTH('a) - 1\) case True then show ?thesis by (simp add: bit_shiftr1_iff bit_of_bl_iff) next case False with \n < LENGTH('a)\ have \n < LENGTH('a) - 1\ by simp with \n < LENGTH('a)\ show ?thesis by (simp add: bit_shiftr1_iff bit_of_bl_iff rev_nth nth_butlast word_size test_bit_word_eq to_bl_nth) qed qed lemma bl_shiftr1: "to_bl (shiftr1 w) = False # butlast (to_bl w)" for w :: "'a::len word" by (simp add: shiftr1_bl word_rep_drop len_gt_0 [THEN Suc_leI]) \ \Generalized version of \bl_shiftr1\. Maybe this one should replace it?\ lemma bl_shiftr1': "to_bl (shiftr1 w) = butlast (False # to_bl w)" apply (rule word_bl.Abs_inverse') apply (simp del: butlast.simps) apply (simp add: shiftr1_bl of_bl_def) done lemma bl_sshiftr1: "to_bl (sshiftr1 w) = hd (to_bl w) # butlast (to_bl w)" for w :: "'a::len word" proof (rule nth_equalityI) fix n assume \n < length (to_bl (sshiftr1 w))\ then have \n < LENGTH('a)\ by simp then show \to_bl (sshiftr1 w) ! n \ (hd (to_bl w) # butlast (to_bl w)) ! n\ apply (cases n) apply (simp_all add: to_bl_nth word_size hd_conv_nth test_bit_eq_bit bit_sshiftr1_iff nth_butlast Suc_diff_Suc nth_to_bl) done qed simp lemma drop_shiftr: "drop n (to_bl (w >> n)) = take (size w - n) (to_bl w)" for w :: "'a::len word" apply (unfold shiftr_def) apply (induct n) prefer 2 apply (simp add: drop_Suc bl_shiftr1 butlast_drop [symmetric]) apply (rule butlast_take [THEN trans]) apply (auto simp: word_size) done lemma drop_sshiftr: "drop n (to_bl (w >>> n)) = take (size w - n) (to_bl w)" for w :: "'a::len word" apply (simp_all add: word_size sshiftr_eq) apply (rule nth_equalityI) apply (simp_all add: word_size nth_to_bl bit_signed_drop_bit_iff) done lemma take_shiftr: "n \ size w \ take n (to_bl (w >> n)) = replicate n False" apply (unfold shiftr_def) apply (induct n) prefer 2 apply (simp add: bl_shiftr1' length_0_conv [symmetric] word_size) apply (rule take_butlast [THEN trans]) apply (auto simp: word_size) done lemma take_sshiftr': "n \ size w \ hd (to_bl (w >>> n)) = hd (to_bl w) \ take n (to_bl (w >>> n)) = replicate n (hd (to_bl w))" for w :: "'a::len word" apply (auto simp add: sshiftr_eq hd_bl_sign_sint bin_sign_def not_le word_size sint_signed_drop_bit_eq) apply (rule nth_equalityI) apply (auto simp add: nth_to_bl bit_signed_drop_bit_iff bit_last_iff) apply (rule nth_equalityI) apply (auto simp add: nth_to_bl bit_signed_drop_bit_iff bit_last_iff) done lemmas hd_sshiftr = take_sshiftr' [THEN conjunct1] lemmas take_sshiftr = take_sshiftr' [THEN conjunct2] lemma atd_lem: "take n xs = t \ drop n xs = d \ xs = t @ d" by (auto intro: append_take_drop_id [symmetric]) lemmas bl_shiftr = atd_lem [OF take_shiftr drop_shiftr] lemmas bl_sshiftr = atd_lem [OF take_sshiftr drop_sshiftr] lemma shiftl_of_bl: "of_bl bl << n = of_bl (bl @ replicate n False)" by (induct n) (auto simp: shiftl_def shiftl1_of_bl replicate_app_Cons_same) lemma shiftl_bl: "w << n = of_bl (to_bl w @ replicate n False)" for w :: "'a::len word" proof - have "w << n = of_bl (to_bl w) << n" by simp also have "\ = of_bl (to_bl w @ replicate n False)" by (rule shiftl_of_bl) finally show ?thesis . qed lemma bl_shiftl: "to_bl (w << n) = drop n (to_bl w) @ replicate (min (size w) n) False" by (simp add: shiftl_bl word_rep_drop word_size) lemma shiftr1_bl_of: "length bl \ LENGTH('a) \ shiftr1 (of_bl bl::'a::len word) = of_bl (butlast bl)" by transfer (simp add: butlast_rest_bl2bin trunc_bl2bin) lemma shiftr_bl_of: "length bl \ LENGTH('a) \ (of_bl bl::'a::len word) >> n = of_bl (take (length bl - n) bl)" apply (unfold shiftr_def) apply (induct n) apply clarsimp apply clarsimp apply (subst shiftr1_bl_of) apply simp apply (simp add: butlast_take) done lemma shiftr_bl: "x >> n \ of_bl (take (LENGTH('a) - n) (to_bl x))" for x :: "'a::len word" using shiftr_bl_of [where 'a='a, of "to_bl x"] by simp lemma aligned_bl_add_size [OF refl]: "size x - n = m \ n \ size x \ drop m (to_bl x) = replicate n False \ take m (to_bl y) = replicate m False \ to_bl (x + y) = take m (to_bl x) @ drop m (to_bl y)" for x :: \'a::len word\ apply (subgoal_tac "x AND y = 0") prefer 2 apply (rule word_bl.Rep_eqD) apply (simp add: bl_word_and) apply (rule align_lem_and [THEN trans]) apply (simp_all add: word_size)[5] apply simp apply (subst word_plus_and_or [symmetric]) apply (simp add : bl_word_or) apply (rule align_lem_or) apply (simp_all add: word_size) done lemma mask_bl: "mask n = of_bl (replicate n True)" by (auto simp add : test_bit_of_bl word_size intro: word_eqI) lemma bl_and_mask': "to_bl (w AND mask n :: 'a::len word) = replicate (LENGTH('a) - n) False @ drop (LENGTH('a) - n) (to_bl w)" apply (rule nth_equalityI) apply simp apply (clarsimp simp add: to_bl_nth word_size) apply (simp add: word_size word_ops_nth_size) apply (auto simp add: word_size test_bit_bl nth_append rev_nth) done lemma slice1_eq_of_bl: \(slice1 n w :: 'b::len word) = of_bl (takefill False n (to_bl w))\ for w :: \'a::len word\ proof (rule bit_word_eqI) fix m assume \m < LENGTH('b)\ show \bit (slice1 n w :: 'b::len word) m \ bit (of_bl (takefill False n (to_bl w)) :: 'b word) m\ by (cases \m \ n\; cases \LENGTH('a) \ n\) (auto simp add: bit_slice1_iff bit_of_bl_iff not_less rev_nth not_le nth_takefill nth_to_bl algebra_simps) qed lemma slice1_no_bin [simp]: "slice1 n (numeral w :: 'b word) = of_bl (takefill False n (bin_to_bl (LENGTH('b::len)) (numeral w)))" by (simp add: slice1_eq_of_bl) (* TODO: neg_numeral *) lemma slice_no_bin [simp]: "slice n (numeral w :: 'b word) = of_bl (takefill False (LENGTH('b::len) - n) (bin_to_bl (LENGTH('b::len)) (numeral w)))" by (simp add: slice_def) (* TODO: neg_numeral *) lemma slice_take': "slice n w = of_bl (take (size w - n) (to_bl w))" by (simp add: slice_def word_size slice1_eq_of_bl takefill_alt) lemmas slice_take = slice_take' [unfolded word_size] \ \shiftr to a word of the same size is just slice, slice is just shiftr then ucast\ lemmas shiftr_slice = trans [OF shiftr_bl [THEN meta_eq_to_obj_eq] slice_take [symmetric]] lemma slice1_down_alt': "sl = slice1 n w \ fs = size sl \ fs + k = n \ to_bl sl = takefill False fs (drop k (to_bl w))" apply (simp add: slice1_eq_of_bl) apply transfer apply (simp add: bl_bin_bl_rep_drop) using drop_takefill apply force done lemma slice1_up_alt': "sl = slice1 n w \ fs = size sl \ fs = n + k \ to_bl sl = takefill False fs (replicate k False @ (to_bl w))" apply (simp add: slice1_eq_of_bl) apply transfer apply (simp add: bl_bin_bl_rep_drop flip: takefill_append) apply (metis diff_add_inverse) done lemmas sd1 = slice1_down_alt' [OF refl refl, unfolded word_size] lemmas su1 = slice1_up_alt' [OF refl refl, unfolded word_size] lemmas slice1_down_alt = le_add_diff_inverse [THEN sd1] lemmas slice1_up_alts = le_add_diff_inverse [symmetric, THEN su1] le_add_diff_inverse2 [symmetric, THEN su1] lemma slice1_tf_tf': "to_bl (slice1 n w :: 'a::len word) = rev (takefill False (LENGTH('a)) (rev (takefill False n (to_bl w))))" unfolding slice1_eq_of_bl by (rule word_rev_tf) lemmas slice1_tf_tf = slice1_tf_tf' [THEN word_bl.Rep_inverse', symmetric] lemma revcast_eq_of_bl: \(revcast w :: 'b::len word) = of_bl (takefill False (LENGTH('b)) (to_bl w))\ for w :: \'a::len word\ by (simp add: revcast_def slice1_eq_of_bl) lemmas revcast_no_def [simp] = revcast_eq_of_bl [where w="numeral w", unfolded word_size] for w lemma to_bl_revcast: "to_bl (revcast w :: 'a::len word) = takefill False (LENGTH('a)) (to_bl w)" apply (rule nth_equalityI) apply simp apply (cases \LENGTH('a) \ LENGTH('b)\) apply (auto simp add: nth_to_bl nth_takefill bit_revcast_iff) done lemma word_cat_bl: "word_cat a b = of_bl (to_bl a @ to_bl b)" apply (rule bit_word_eqI) apply (simp add: bit_word_cat_iff bit_of_bl_iff nth_append not_less nth_rev_to_bl) apply (meson bit_word.rep_eq less_diff_conv2 nth_rev_to_bl) done lemma of_bl_append: "(of_bl (xs @ ys) :: 'a::len word) = of_bl xs * 2^(length ys) + of_bl ys" apply transfer apply (simp add: bl_to_bin_app_cat bin_cat_num) done lemma of_bl_False [simp]: "of_bl (False#xs) = of_bl xs" by (rule word_eqI) (auto simp: test_bit_of_bl nth_append) lemma of_bl_True [simp]: "(of_bl (True # xs) :: 'a::len word) = 2^length xs + of_bl xs" by (subst of_bl_append [where xs="[True]", simplified]) (simp add: word_1_bl) lemma of_bl_Cons: "of_bl (x#xs) = of_bool x * 2^length xs + of_bl xs" by (cases x) simp_all lemma word_split_bl': "std = size c - size b \ (word_split c = (a, b)) \ (a = of_bl (take std (to_bl c)) \ b = of_bl (drop std (to_bl c)))" apply (simp add: word_split_def) apply transfer apply (cases \LENGTH('b) \ LENGTH('a)\) apply (auto simp add: drop_bit_take_bit drop_bin2bl bin_to_bl_drop_bit [symmetric, of \LENGTH('a)\ \LENGTH('a) - LENGTH('b)\ \LENGTH('b)\] min_absorb2) done lemma word_split_bl: "std = size c - size b \ (a = of_bl (take std (to_bl c)) \ b = of_bl (drop std (to_bl c))) \ word_split c = (a, b)" apply (rule iffI) defer apply (erule (1) word_split_bl') apply (case_tac "word_split c") apply (auto simp add: word_size) apply (frule word_split_bl' [rotated]) apply (auto simp add: word_size) done lemma word_split_bl_eq: "(word_split c :: ('c::len word \ 'd::len word)) = (of_bl (take (LENGTH('a::len) - LENGTH('d::len)) (to_bl c)), of_bl (drop (LENGTH('a) - LENGTH('d)) (to_bl c)))" for c :: "'a::len word" apply (rule word_split_bl [THEN iffD1]) apply (unfold word_size) apply (rule refl conjI)+ done lemma word_rcat_bl: \word_rcat wl = of_bl (concat (map to_bl wl))\ proof - define ws where \ws = rev wl\ moreover have \word_rcat (rev ws) = of_bl (concat (map to_bl (rev ws)))\ apply (simp add: word_rcat_def of_bl_eq rev_concat rev_map comp_def rev_to_bl_eq flip: horner_sum_of_bool_2_concat) apply transfer apply simp done ultimately show ?thesis by simp qed lemma size_rcat_lem': "size (concat (map to_bl wl)) = length wl * size (hd wl)" by (induct wl) (auto simp: word_size) lemmas size_rcat_lem = size_rcat_lem' [unfolded word_size] lemma nth_rcat_lem: "n < length (wl::'a word list) * LENGTH('a::len) \ rev (concat (map to_bl wl)) ! n = rev (to_bl (rev wl ! (n div LENGTH('a)))) ! (n mod LENGTH('a))" apply (induct wl) apply clarsimp apply (clarsimp simp add : nth_append size_rcat_lem) apply (simp flip: mult_Suc minus_div_mult_eq_mod add: less_Suc_eq_le not_less) apply (metis (no_types, lifting) diff_is_0_eq div_le_mono len_not_eq_0 less_Suc_eq less_mult_imp_div_less nonzero_mult_div_cancel_right not_le nth_Cons_0) done lemma foldl_eq_foldr: "foldl (+) x xs = foldr (+) (x # xs) 0" for x :: "'a::comm_monoid_add" by (induct xs arbitrary: x) (auto simp: add.assoc) lemmas word_cat_bl_no_bin [simp] = word_cat_bl [where a="numeral a" and b="numeral b", unfolded to_bl_numeral] for a b (* FIXME: negative numerals, 0 and 1 *) lemmas word_split_bl_no_bin [simp] = word_split_bl_eq [where c="numeral c", unfolded to_bl_numeral] for c lemmas word_rot_defs = word_roti_eq_word_rotr_word_rotl word_rotr_eq word_rotl_eq lemma to_bl_rotl: "to_bl (word_rotl n w) = rotate n (to_bl w)" by (simp add: word_rotl_eq to_bl_use_of_bl) lemmas blrs0 = rotate_eqs [THEN to_bl_rotl [THEN trans]] lemmas word_rotl_eqs = blrs0 [simplified word_bl_Rep' word_bl.Rep_inject to_bl_rotl [symmetric]] lemma to_bl_rotr: "to_bl (word_rotr n w) = rotater n (to_bl w)" by (simp add: word_rotr_eq to_bl_use_of_bl) lemmas brrs0 = rotater_eqs [THEN to_bl_rotr [THEN trans]] lemmas word_rotr_eqs = brrs0 [simplified word_bl_Rep' word_bl.Rep_inject to_bl_rotr [symmetric]] declare word_rotr_eqs (1) [simp] declare word_rotl_eqs (1) [simp] lemmas abl_cong = arg_cong [where f = "of_bl"] locale word_rotate begin lemmas word_rot_defs' = to_bl_rotl to_bl_rotr lemmas blwl_syms [symmetric] = bl_word_not bl_word_and bl_word_or bl_word_xor lemmas lbl_lbl = trans [OF word_bl_Rep' word_bl_Rep' [symmetric]] lemmas ths_map2 [OF lbl_lbl] = rotate_map2 rotater_map2 lemmas ths_map [where xs = "to_bl v"] = rotate_map rotater_map for v lemmas th1s [simplified word_rot_defs' [symmetric]] = ths_map2 ths_map end lemmas bl_word_rotl_dt = trans [OF to_bl_rotl rotate_drop_take, simplified word_bl_Rep'] lemmas bl_word_rotr_dt = trans [OF to_bl_rotr rotater_drop_take, simplified word_bl_Rep'] lemma bl_word_roti_dt': "n = nat ((- i) mod int (size (w :: 'a::len word))) \ to_bl (word_roti i w) = drop n (to_bl w) @ take n (to_bl w)" apply (unfold word_roti_eq_word_rotr_word_rotl) apply (simp add: bl_word_rotl_dt bl_word_rotr_dt word_size) apply safe apply (simp add: zmod_zminus1_eq_if) apply safe apply (simp add: nat_mult_distrib) apply (simp add: nat_diff_distrib [OF pos_mod_sign pos_mod_conj [THEN conjunct2, THEN order_less_imp_le]] nat_mod_distrib) apply (simp add: nat_mod_distrib) done lemmas bl_word_roti_dt = bl_word_roti_dt' [unfolded word_size] lemmas word_rotl_dt = bl_word_rotl_dt [THEN word_bl.Rep_inverse' [symmetric]] lemmas word_rotr_dt = bl_word_rotr_dt [THEN word_bl.Rep_inverse' [symmetric]] lemmas word_roti_dt = bl_word_roti_dt [THEN word_bl.Rep_inverse' [symmetric]] lemmas word_rotr_dt_no_bin' [simp] = word_rotr_dt [where w="numeral w", unfolded to_bl_numeral] for w (* FIXME: negative numerals, 0 and 1 *) lemmas word_rotl_dt_no_bin' [simp] = word_rotl_dt [where w="numeral w", unfolded to_bl_numeral] for w (* FIXME: negative numerals, 0 and 1 *) lemma max_word_bl: "to_bl (max_word::'a::len word) = replicate LENGTH('a) True" by (fact to_bl_n1) lemma to_bl_mask: "to_bl (mask n :: 'a::len word) = replicate (LENGTH('a) - n) False @ replicate (min (LENGTH('a)) n) True" by (simp add: mask_bl word_rep_drop min_def) lemma map_replicate_True: "n = length xs \ map (\(x,y). x \ y) (zip xs (replicate n True)) = xs" by (induct xs arbitrary: n) auto lemma map_replicate_False: "n = length xs \ map (\(x,y). x \ y) (zip xs (replicate n False)) = replicate n False" by (induct xs arbitrary: n) auto lemma bl_and_mask: fixes w :: "'a::len word" and n :: nat defines "n' \ LENGTH('a) - n" shows "to_bl (w AND mask n) = replicate n' False @ drop n' (to_bl w)" proof - note [simp] = map_replicate_True map_replicate_False have "to_bl (w AND mask n) = map2 (\) (to_bl w) (to_bl (mask n::'a::len word))" by (simp add: bl_word_and) also have "to_bl w = take n' (to_bl w) @ drop n' (to_bl w)" by simp also have "map2 (\) \ (to_bl (mask n::'a::len word)) = replicate n' False @ drop n' (to_bl w)" unfolding to_bl_mask n'_def by (subst zip_append) auto finally show ?thesis . qed lemma drop_rev_takefill: "length xs \ n \ drop (n - length xs) (rev (takefill False n (rev xs))) = xs" by (simp add: takefill_alt rev_take) declare bin_to_bl_def [simp] end diff --git a/thys/Word_Lib/Traditional_Infix_Syntax.thy b/thys/Word_Lib/Traditional_Infix_Syntax.thy --- a/thys/Word_Lib/Traditional_Infix_Syntax.thy +++ b/thys/Word_Lib/Traditional_Infix_Syntax.thy @@ -1,534 +1,534 @@ (* Author: Jeremy Dawson, NICTA *) section \Operation variants with traditional syntax\ theory Traditional_Infix_Syntax imports "HOL-Library.Word" begin class semiring_bit_syntax = semiring_bit_shifts begin definition test_bit :: \'a \ nat \ bool\ (infixl "!!" 100) where test_bit_eq_bit: \test_bit = bit\ definition shiftl :: \'a \ nat \ 'a\ (infixl "<<" 55) where shiftl_eq_push_bit: \a << n = push_bit n a\ definition shiftr :: \'a \ nat \ 'a\ (infixl ">>" 55) where shiftr_eq_drop_bit: \a >> n = drop_bit n a\ end instance word :: (len) semiring_bit_syntax .. context includes lifting_syntax begin lemma test_bit_word_transfer [transfer_rule]: \(pcr_word ===> (=)) (\k n. n < LENGTH('a) \ bit k n) (test_bit :: 'a::len word \ _)\ by (unfold test_bit_eq_bit) transfer_prover lemma shiftl_word_transfer [transfer_rule]: \(pcr_word ===> (=) ===> pcr_word) (\k n. push_bit n k) shiftl\ by (unfold shiftl_eq_push_bit) transfer_prover lemma shiftr_word_transfer [transfer_rule]: \(pcr_word ===> (=) ===> pcr_word) (\k n. (drop_bit n \ take_bit LENGTH('a)) k) (shiftr :: 'a::len word \ _)\ by (unfold shiftr_eq_drop_bit) transfer_prover end lemma test_bit_word_eq: \test_bit = (bit :: 'a::len word \ _)\ by (fact test_bit_eq_bit) lemma shiftl_word_eq: \w << n = push_bit n w\ for w :: \'a::len word\ by (fact shiftl_eq_push_bit) lemma shiftr_word_eq: \w >> n = drop_bit n w\ for w :: \'a::len word\ by (fact shiftr_eq_drop_bit) lemma test_bit_eq_iff: "test_bit u = test_bit v \ u = v" for u v :: "'a::len word" by (simp add: bit_eq_iff test_bit_eq_bit fun_eq_iff) lemma test_bit_size: "w !! n \ n < size w" for w :: "'a::len word" by transfer simp lemma word_eq_iff: "x = y \ (\n?P \ ?Q\) for x y :: "'a::len word" by transfer (auto simp add: bit_eq_iff bit_take_bit_iff) lemma word_eqI: "(\n. n < size u \ u !! n = v !! n) \ u = v" for u :: "'a::len word" by (simp add: word_size word_eq_iff) lemma word_eqD: "u = v \ u !! x = v !! x" for u v :: "'a::len word" by simp lemma test_bit_bin': "w !! n \ n < size w \ bit (uint w) n" by transfer (simp add: bit_take_bit_iff) lemmas test_bit_bin = test_bit_bin' [unfolded word_size] lemma word_test_bit_def: \test_bit a = bit (uint a)\ by transfer (simp add: fun_eq_iff bit_take_bit_iff) lemmas test_bit_def' = word_test_bit_def [THEN fun_cong] lemma word_test_bit_transfer [transfer_rule]: "(rel_fun pcr_word (rel_fun (=) (=))) (\x n. n < LENGTH('a) \ bit x n) (test_bit :: 'a::len word \ _)" by (simp only: test_bit_eq_bit) transfer_prover lemma test_bit_wi [simp]: "(word_of_int x :: 'a::len word) !! n \ n < LENGTH('a) \ bit x n" by transfer simp lemma word_ops_nth_size: "n < size x \ (x OR y) !! n = (x !! n | y !! n) \ (x AND y) !! n = (x !! n \ y !! n) \ (x XOR y) !! n = (x !! n \ y !! n) \ (NOT x) !! n = (\ x !! n)" for x :: "'a::len word" by transfer (simp add: bit_or_iff bit_and_iff bit_xor_iff bit_not_iff) lemma word_ao_nth: "(x OR y) !! n = (x !! n | y !! n) \ (x AND y) !! n = (x !! n \ y !! n)" for x :: "'a::len word" by transfer (auto simp add: bit_or_iff bit_and_iff) lemmas msb0 = len_gt_0 [THEN diff_Suc_less, THEN word_ops_nth_size [unfolded word_size]] lemmas msb1 = msb0 [where i = 0] lemma test_bit_numeral [simp]: "(numeral w :: 'a::len word) !! n \ n < LENGTH('a) \ bit (numeral w :: int) n" by transfer (rule refl) lemma test_bit_neg_numeral [simp]: "(- numeral w :: 'a::len word) !! n \ n < LENGTH('a) \ bit (- numeral w :: int) n" by transfer (rule refl) lemma test_bit_1 [simp]: "(1 :: 'a::len word) !! n \ n = 0" by transfer (auto simp add: bit_1_iff) lemma nth_0 [simp]: "\ (0 :: 'a::len word) !! n" by transfer simp lemma nth_minus1 [simp]: "(-1 :: 'a::len word) !! n \ n < LENGTH('a)" by transfer simp lemma shiftl1_code [code]: \shiftl1 w = push_bit 1 w\ by transfer (simp add: ac_simps) lemma uint_shiftr_eq: \uint (w >> n) = uint w div 2 ^ n\ by transfer (simp flip: drop_bit_eq_div add: drop_bit_take_bit min_def le_less less_diff_conv) lemma shiftr1_code [code]: \shiftr1 w = drop_bit 1 w\ by transfer (simp add: drop_bit_Suc) lemma shiftl_def: \w << n = (shiftl1 ^^ n) w\ proof - have \push_bit n = (((*) 2 ^^ n) :: int \ int)\ for n by (induction n) (simp_all add: fun_eq_iff funpow_swap1, simp add: ac_simps) then show ?thesis by transfer simp qed lemma shiftr_def: \w >> n = (shiftr1 ^^ n) w\ proof - have \shiftr1 ^^ n = (drop_bit n :: 'a word \ 'a word)\ apply (induction n) apply simp apply (simp only: shiftr1_eq_div_2 [abs_def] drop_bit_eq_div [abs_def] funpow_Suc_right) apply (use div_exp_eq [of _ 1, where ?'a = \'a word\] in simp) done then show ?thesis by (simp add: shiftr_eq_drop_bit) qed -lemma bit_shiftl_word_iff: +lemma bit_shiftl_word_iff [bit_simps]: \bit (w << m) n \ m \ n \ n < LENGTH('a) \ bit w (n - m)\ for w :: \'a::len word\ by (simp add: shiftl_word_eq bit_push_bit_iff exp_eq_zero_iff not_le) -lemma bit_shiftr_word_iff: +lemma bit_shiftr_word_iff [bit_simps]: \bit (w >> m) n \ bit w (m + n)\ for w :: \'a::len word\ by (simp add: shiftr_word_eq bit_drop_bit_eq) lift_definition sshiftr :: \'a::len word \ nat \ 'a word\ (infixl \>>>\ 55) is \\k n. take_bit LENGTH('a) (drop_bit n (signed_take_bit (LENGTH('a) - Suc 0) k))\ by (simp flip: signed_take_bit_decr_length_iff) lemma sshiftr_eq [code]: \w >>> n = signed_drop_bit n w\ by transfer simp lemma sshiftr_eq_funpow_sshiftr1: \w >>> n = (sshiftr1 ^^ n) w\ apply (rule sym) apply (simp add: sshiftr1_eq_signed_drop_bit_Suc_0 sshiftr_eq) apply (induction n) apply simp_all done lemma uint_sshiftr_eq: \uint (w >>> n) = take_bit LENGTH('a) (sint w div 2 ^ n)\ for w :: \'a::len word\ by transfer (simp flip: drop_bit_eq_div) lemma sshift1_code [code]: \sshiftr1 w = signed_drop_bit 1 w\ by transfer (simp add: drop_bit_Suc) lemma sshiftr_0 [simp]: "0 >>> n = 0" by transfer simp lemma sshiftr_n1 [simp]: "-1 >>> n = -1" by transfer simp -lemma bit_sshiftr_word_iff: +lemma bit_sshiftr_word_iff [bit_simps]: \bit (w >>> m) n \ bit w (if LENGTH('a) - m \ n \ n < LENGTH('a) then LENGTH('a) - 1 else (m + n))\ for w :: \'a::len word\ apply transfer apply (auto simp add: bit_take_bit_iff bit_drop_bit_eq bit_signed_take_bit_iff min_def not_le simp flip: bit_Suc) using le_less_Suc_eq apply fastforce using le_less_Suc_eq apply fastforce done lemma nth_sshiftr : "(w >>> m) !! n = (n < size w \ (if n + m \ size w then w !! (size w - 1) else w !! (n + m)))" apply transfer apply (auto simp add: bit_take_bit_iff bit_drop_bit_eq bit_signed_take_bit_iff min_def not_le ac_simps) using le_less_Suc_eq apply fastforce using le_less_Suc_eq apply fastforce done lemma sshiftr_numeral [simp]: \(numeral k >>> numeral n :: 'a::len word) = word_of_int (drop_bit (numeral n) (signed_take_bit (LENGTH('a) - 1) (numeral k)))\ apply (rule word_eqI) apply (cases \LENGTH('a)\) apply (simp_all add: word_size bit_drop_bit_eq nth_sshiftr bit_signed_take_bit_iff min_def not_le not_less less_Suc_eq_le ac_simps) done lemma revcast_down_us [OF refl]: "rc = revcast \ source_size rc = target_size rc + n \ rc w = ucast (w >>> n)" for w :: "'a::len word" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_ucast_iff bit_sshiftr_word_iff ac_simps) done lemma revcast_down_ss [OF refl]: "rc = revcast \ source_size rc = target_size rc + n \ rc w = scast (w >>> n)" for w :: "'a::len word" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_word_scast_iff bit_sshiftr_word_iff ac_simps) done lemma sshiftr_div_2n: "sint (w >>> n) = sint w div 2 ^ n" using sint_signed_drop_bit_eq [of n w] by (simp add: drop_bit_eq_div sshiftr_eq) lemmas lsb0 = len_gt_0 [THEN word_ops_nth_size [unfolded word_size]] lemma nth_sint: fixes w :: "'a::len word" defines "l \ LENGTH('a)" shows "bit (sint w) n = (if n < l - 1 then w !! n else w !! (l - 1))" unfolding sint_uint l_def by (auto simp: bit_signed_take_bit_iff word_test_bit_def not_less min_def) lemma test_bit_2p: "(word_of_int (2 ^ n)::'a::len word) !! m \ m = n \ m < LENGTH('a)" by transfer (auto simp add: bit_exp_iff) lemma nth_w2p: "((2::'a::len word) ^ n) !! m \ m = n \ m < LENGTH('a::len)" by transfer (auto simp add: bit_exp_iff) lemma bang_is_le: "x !! m \ 2 ^ m \ x" for x :: "'a::len word" apply (rule xtrans(3)) apply (rule_tac [2] y = "x" in le_word_or2) apply (rule word_eqI) apply (auto simp add: word_ao_nth nth_w2p word_size) done lemma mask_eq: \mask n = (1 << n) - (1 :: 'a::len word)\ by transfer (simp add: mask_eq_exp_minus_1 push_bit_of_1) lemma nth_ucast: "(ucast w::'a::len word) !! n = (w !! n \ n < LENGTH('a))" by transfer (simp add: bit_take_bit_iff ac_simps) lemma shiftl_0 [simp]: "(0::'a::len word) << n = 0" by transfer simp lemma shiftr_0 [simp]: "(0::'a::len word) >> n = 0" by transfer simp lemma nth_shiftl1: "shiftl1 w !! n \ n < size w \ n > 0 \ w !! (n - 1)" by transfer (auto simp add: bit_double_iff) lemma nth_shiftl': "(w << m) !! n \ n < size w \ n >= m \ w !! (n - m)" for w :: "'a::len word" by transfer (auto simp add: bit_push_bit_iff) lemmas nth_shiftl = nth_shiftl' [unfolded word_size] lemma nth_shiftr1: "shiftr1 w !! n = w !! Suc n" by transfer (auto simp add: bit_take_bit_iff simp flip: bit_Suc) lemma nth_shiftr: "(w >> m) !! n = w !! (n + m)" for w :: "'a::len word" apply (unfold shiftr_def) apply (induct "m" arbitrary: n) apply (auto simp add: nth_shiftr1) done lemma nth_sshiftr1: "sshiftr1 w !! n = (if n = size w - 1 then w !! n else w !! Suc n)" apply transfer apply (auto simp add: bit_take_bit_iff bit_signed_take_bit_iff min_def simp flip: bit_Suc) using le_less_Suc_eq apply fastforce using le_less_Suc_eq apply fastforce done lemma shiftr_div_2n: "uint (shiftr w n) = uint w div 2 ^ n" by (fact uint_shiftr_eq) lemma shiftl_rev: "shiftl w n = word_reverse (shiftr (word_reverse w) n)" by (induct n) (auto simp add: shiftl_def shiftr_def shiftl1_rev) lemma rev_shiftl: "word_reverse w << n = word_reverse (w >> n)" by (simp add: shiftl_rev) lemma shiftr_rev: "w >> n = word_reverse (word_reverse w << n)" by (simp add: rev_shiftl) lemma rev_shiftr: "word_reverse w >> n = word_reverse (w << n)" by (simp add: shiftr_rev) lemma shiftl_numeral [simp]: \numeral k << numeral l = (push_bit (numeral l) (numeral k) :: 'a::len word)\ by (fact shiftl_word_eq) lemma shiftl_zero_size: "size x \ n \ x << n = 0" for x :: "'a::len word" apply transfer apply (simp add: take_bit_push_bit) done lemma shiftl_t2n: "shiftl w n = 2 ^ n * w" for w :: "'a::len word" by (induct n) (auto simp: shiftl_def shiftl1_2t) lemma shiftr_numeral [simp]: \(numeral k >> numeral n :: 'a::len word) = drop_bit (numeral n) (numeral k)\ by (fact shiftr_word_eq) lemma nth_mask [simp]: \(mask n :: 'a::len word) !! i \ i < n \ i < size (mask n :: 'a word)\ by (auto simp add: test_bit_word_eq word_size Word.bit_mask_iff) lemma slice_shiftr: "slice n w = ucast (w >> n)" apply (rule bit_word_eqI) apply (cases \n \ LENGTH('b)\) apply (auto simp add: bit_slice_iff bit_ucast_iff bit_shiftr_word_iff ac_simps dest: bit_imp_le_length) done lemma nth_slice: "(slice n w :: 'a::len word) !! m = (w !! (m + n) \ m < LENGTH('a))" by (simp add: slice_shiftr nth_ucast nth_shiftr) lemma revcast_down_uu [OF refl]: "rc = revcast \ source_size rc = target_size rc + n \ rc w = ucast (w >> n)" for w :: "'a::len word" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_ucast_iff bit_shiftr_word_iff ac_simps) done lemma revcast_down_su [OF refl]: "rc = revcast \ source_size rc = target_size rc + n \ rc w = scast (w >> n)" for w :: "'a::len word" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_word_scast_iff bit_shiftr_word_iff ac_simps) done lemma cast_down_rev [OF refl]: "uc = ucast \ source_size uc = target_size uc + n \ uc w = revcast (w << n)" for w :: "'a::len word" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_word_ucast_iff bit_shiftl_word_iff) done lemma revcast_up [OF refl]: "rc = revcast \ source_size rc + n = target_size rc \ rc w = (ucast w :: 'a::len word) << n" apply (simp add: source_size_def target_size_def) apply (rule bit_word_eqI) apply (simp add: bit_revcast_iff bit_word_ucast_iff bit_shiftl_word_iff) apply auto apply (metis add.commute add_diff_cancel_right) apply (metis diff_add_inverse2 diff_diff_add) done lemmas rc1 = revcast_up [THEN revcast_rev_ucast [symmetric, THEN trans, THEN word_rev_gal, symmetric]] lemmas rc2 = revcast_down_uu [THEN revcast_rev_ucast [symmetric, THEN trans, THEN word_rev_gal, symmetric]] lemmas ucast_up = rc1 [simplified rev_shiftr [symmetric] revcast_ucast [symmetric]] lemmas ucast_down = rc2 [simplified rev_shiftr revcast_ucast [symmetric]] \ \problem posed by TPHOLs referee: criterion for overflow of addition of signed integers\ lemma sofl_test: \sint x + sint y = sint (x + y) \ (x + y XOR x) AND (x + y XOR y) >> (size x - 1) = 0\ for x y :: \'a::len word\ proof - obtain n where n: \LENGTH('a) = Suc n\ by (cases \LENGTH('a)\) simp_all have *: \sint x + sint y + 2 ^ Suc n > signed_take_bit n (sint x + sint y) \ sint x + sint y \ - (2 ^ n)\ \signed_take_bit n (sint x + sint y) > sint x + sint y - 2 ^ Suc n \ 2 ^ n > sint x + sint y\ using signed_take_bit_int_greater_eq [of \sint x + sint y\ n] signed_take_bit_int_less_eq [of n \sint x + sint y\] by (auto intro: ccontr) have \sint x + sint y = sint (x + y) \ (sint (x + y) < 0 \ sint x < 0) \ (sint (x + y) < 0 \ sint y < 0)\ using sint_less [of x] sint_greater_eq [of x] sint_less [of y] sint_greater_eq [of y] signed_take_bit_int_eq_self [of \LENGTH('a) - 1\ \sint x + sint y\] apply (auto simp add: not_less) apply (unfold sint_word_ariths) apply (subst signed_take_bit_int_eq_self) prefer 4 apply (subst signed_take_bit_int_eq_self) prefer 7 apply (subst signed_take_bit_int_eq_self) prefer 10 apply (subst signed_take_bit_int_eq_self) apply (auto simp add: signed_take_bit_int_eq_self signed_take_bit_eq_take_bit_minus take_bit_Suc_from_most n not_less intro!: *) done then show ?thesis apply (simp only: One_nat_def word_size shiftr_word_eq drop_bit_eq_zero_iff_not_bit_last bit_and_iff bit_xor_iff) apply (simp add: bit_last_iff) done qed lemma shiftr_zero_size: "size x \ n \ x >> n = 0" for x :: "'a :: len word" by (rule word_eqI) (auto simp add: nth_shiftr dest: test_bit_size) lemma test_bit_cat [OF refl]: "wc = word_cat a b \ wc !! n = (n < size wc \ (if n < size b then b !! n else a !! (n - size b)))" apply (simp add: word_size not_less; transfer) apply (auto simp add: bit_concat_bit_iff bit_take_bit_iff) done \ \keep quantifiers for use in simplification\ lemma test_bit_split': "word_split c = (a, b) \ (\n m. b !! n = (n < size b \ c !! n) \ a !! m = (m < size a \ c !! (m + size b)))" by (auto simp add: word_split_bin' test_bit_bin bit_unsigned_iff word_size bit_drop_bit_eq ac_simps exp_eq_zero_iff dest: bit_imp_le_length) lemma test_bit_split: "word_split c = (a, b) \ (\n::nat. b !! n \ n < size b \ c !! n) \ (\m::nat. a !! m \ m < size a \ c !! (m + size b))" by (simp add: test_bit_split') lemma test_bit_split_eq: "word_split c = (a, b) \ ((\n::nat. b !! n = (n < size b \ c !! n)) \ (\m::nat. a !! m = (m < size a \ c !! (m + size b))))" apply (rule_tac iffI) apply (rule_tac conjI) apply (erule test_bit_split [THEN conjunct1]) apply (erule test_bit_split [THEN conjunct2]) apply (case_tac "word_split c") apply (frule test_bit_split) apply (erule trans) apply (fastforce intro!: word_eqI simp add: word_size) done lemma test_bit_rcat: "sw = size (hd wl) \ rc = word_rcat wl \ rc !! n = (n < size rc \ n div sw < size wl \ (rev wl) ! (n div sw) !! (n mod sw))" for wl :: "'a::len word list" by (simp add: word_size word_rcat_def foldl_map rev_map bit_horner_sum_uint_exp_iff) (simp add: test_bit_eq_bit) lemmas test_bit_cong = arg_cong [where f = "test_bit", THEN fun_cong] lemma max_test_bit: "(max_word::'a::len word) !! n \ n < LENGTH('a)" by (fact nth_minus1) lemma shiftr_x_0 [iff]: "x >> 0 = x" for x :: "'a::len word" by transfer simp lemma shiftl_x_0 [simp]: "x << 0 = x" for x :: "'a::len word" by (simp add: shiftl_t2n) lemma shiftl_1 [simp]: "(1::'a::len word) << n = 2^n" by (simp add: shiftl_t2n) lemma shiftr_1[simp]: "(1::'a::len word) >> n = (if n = 0 then 1 else 0)" by (induct n) (auto simp: shiftr_def) lemma map_nth_0 [simp]: "map ((!!) (0::'a::len word)) xs = replicate (length xs) False" by (induct xs) auto lemma word_and_1: "n AND 1 = (if n !! 0 then 1 else 0)" for n :: "_ word" by (rule bit_word_eqI) (auto simp add: bit_and_iff test_bit_eq_bit bit_1_iff intro: gr0I) lemma test_bit_1' [simp]: "(1 :: 'a :: len word) !! n \ 0 < LENGTH('a) \ n = 0" by simp lemma shiftl0: "x << 0 = (x :: 'a :: len word)" by (fact shiftl_x_0) setup \ Context.theory_map (fold SMT_Word.add_word_shift' [ (\<^term>\shiftl :: 'a::len word \ _\, "bvshl"), (\<^term>\shiftr :: 'a::len word \ _\, "bvlshr"), (\<^term>\sshiftr :: 'a::len word \ _\, "bvashr") ]) \ end