diff --git a/src/HOL/Library/AList.thy b/src/HOL/Library/AList.thy --- a/src/HOL/Library/AList.thy +++ b/src/HOL/Library/AList.thy @@ -1,768 +1,768 @@ (* Title: HOL/Library/AList.thy Author: Norbert Schirmer, Tobias Nipkow, Martin Wildmoser, TU Muenchen *) section \Implementation of Association Lists\ theory AList imports Main begin context begin text \ The operations preserve distinctness of keys and function \<^term>\clearjunk\ distributes over them. Since \<^term>\clearjunk\ enforces distinctness of keys it can be used to establish the invariant, e.g. for inductive proofs. \ subsection \\update\ and \updates\\ qualified primrec update :: "'key \ 'val \ ('key \ 'val) list \ ('key \ 'val) list" where "update k v [] = [(k, v)]" | "update k v (p # ps) = (if fst p = k then (k, v) # ps else p # update k v ps)" lemma update_conv': "map_of (update k v al) = (map_of al)(k\v)" by (induct al) (auto simp add: fun_eq_iff) corollary update_conv: "map_of (update k v al) k' = ((map_of al)(k\v)) k'" by (simp add: update_conv') lemma dom_update: "fst ` set (update k v al) = {k} \ fst ` set al" by (induct al) auto lemma update_keys: "map fst (update k v al) = (if k \ set (map fst al) then map fst al else map fst al @ [k])" by (induct al) simp_all lemma distinct_update: assumes "distinct (map fst al)" shows "distinct (map fst (update k v al))" using assms by (simp add: update_keys) lemma update_filter: "a \ k \ update k v [q\ps. fst q \ a] = [q\update k v ps. fst q \ a]" by (induct ps) auto lemma update_triv: "map_of al k = Some v \ update k v al = al" by (induct al) auto lemma update_nonempty [simp]: "update k v al \ []" by (induct al) auto lemma update_eqD: "update k v al = update k v' al' \ v = v'" proof (induct al arbitrary: al') case Nil then show ?case by (cases al') (auto split: if_split_asm) next case Cons then show ?case by (cases al') (auto split: if_split_asm) qed lemma update_last [simp]: "update k v (update k v' al) = update k v al" by (induct al) auto text \Note that the lists are not necessarily the same: \<^term>\update k v (update k' v' []) = [(k', v'), (k, v)]\ and \<^term>\update k' v' (update k v []) = [(k, v), (k', v')]\.\ lemma update_swap: "k \ k' \ map_of (update k v (update k' v' al)) = map_of (update k' v' (update k v al))" by (simp add: update_conv' fun_eq_iff) lemma update_Some_unfold: "map_of (update k v al) x = Some y \ x = k \ v = y \ x \ k \ map_of al x = Some y" by (simp add: update_conv' map_upd_Some_unfold) lemma image_update [simp]: "x \ A \ map_of (update x y al) ` A = map_of al ` A" by (auto simp add: update_conv') qualified definition updates :: "'key list \ 'val list \ ('key \ 'val) list \ ('key \ 'val) list" where "updates ks vs = fold (case_prod update) (zip ks vs)" lemma updates_simps [simp]: "updates [] vs ps = ps" "updates ks [] ps = ps" "updates (k#ks) (v#vs) ps = updates ks vs (update k v ps)" by (simp_all add: updates_def) lemma updates_key_simp [simp]: "updates (k # ks) vs ps = (case vs of [] \ ps | v # vs \ updates ks vs (update k v ps))" by (cases vs) simp_all lemma updates_conv': "map_of (updates ks vs al) = (map_of al)(ks[\]vs)" proof - have "map_of \ fold (case_prod update) (zip ks vs) = fold (\(k, v) f. f(k \ v)) (zip ks vs) \ map_of" by (rule fold_commute) (auto simp add: fun_eq_iff update_conv') then show ?thesis by (auto simp add: updates_def fun_eq_iff map_upds_fold_map_upd foldl_conv_fold split_def) qed lemma updates_conv: "map_of (updates ks vs al) k = ((map_of al)(ks[\]vs)) k" by (simp add: updates_conv') lemma distinct_updates: assumes "distinct (map fst al)" shows "distinct (map fst (updates ks vs al))" proof - have "distinct (fold (\(k, v) al. if k \ set al then al else al @ [k]) (zip ks vs) (map fst al))" by (rule fold_invariant [of "zip ks vs" "\_. True"]) (auto intro: assms) moreover have "map fst \ fold (case_prod update) (zip ks vs) = fold (\(k, v) al. if k \ set al then al else al @ [k]) (zip ks vs) \ map fst" by (rule fold_commute) (simp add: update_keys split_def case_prod_beta comp_def) ultimately show ?thesis by (simp add: updates_def fun_eq_iff) qed lemma updates_append1[simp]: "size ks < size vs \ updates (ks@[k]) vs al = update k (vs!size ks) (updates ks vs al)" by (induct ks arbitrary: vs al) (auto split: list.splits) lemma updates_list_update_drop[simp]: "size ks \ i \ i < size vs \ updates ks (vs[i:=v]) al = updates ks vs al" by (induct ks arbitrary: al vs i) (auto split: list.splits nat.splits) lemma update_updates_conv_if: "map_of (updates xs ys (update x y al)) = map_of (if x \ set (take (length ys) xs) then updates xs ys al else (update x y (updates xs ys al)))" by (simp add: updates_conv' update_conv' map_upd_upds_conv_if) lemma updates_twist [simp]: "k \ set ks \ map_of (updates ks vs (update k v al)) = map_of (update k v (updates ks vs al))" by (simp add: updates_conv' update_conv') lemma updates_apply_notin [simp]: "k \ set ks \ map_of (updates ks vs al) k = map_of al k" by (simp add: updates_conv) lemma updates_append_drop [simp]: "size xs = size ys \ updates (xs @ zs) ys al = updates xs ys al" by (induct xs arbitrary: ys al) (auto split: list.splits) lemma updates_append2_drop [simp]: "size xs = size ys \ updates xs (ys @ zs) al = updates xs ys al" by (induct xs arbitrary: ys al) (auto split: list.splits) subsection \\delete\\ qualified definition delete :: "'key \ ('key \ 'val) list \ ('key \ 'val) list" where delete_eq: "delete k = filter (\(k', _). k \ k')" lemma delete_simps [simp]: "delete k [] = []" "delete k (p # ps) = (if fst p = k then delete k ps else p # delete k ps)" by (auto simp add: delete_eq) lemma delete_conv': "map_of (delete k al) = (map_of al)(k := None)" by (induct al) (auto simp add: fun_eq_iff) corollary delete_conv: "map_of (delete k al) k' = ((map_of al)(k := None)) k'" by (simp add: delete_conv') lemma delete_keys: "map fst (delete k al) = removeAll k (map fst al)" by (simp add: delete_eq removeAll_filter_not_eq filter_map split_def comp_def) lemma distinct_delete: assumes "distinct (map fst al)" shows "distinct (map fst (delete k al))" using assms by (simp add: delete_keys distinct_removeAll) lemma delete_id [simp]: "k \ fst ` set al \ delete k al = al" by (auto simp add: image_iff delete_eq filter_id_conv) lemma delete_idem: "delete k (delete k al) = delete k al" by (simp add: delete_eq) lemma map_of_delete [simp]: "k' \ k \ map_of (delete k al) k' = map_of al k'" by (simp add: delete_conv') lemma delete_notin_dom: "k \ fst ` set (delete k al)" by (auto simp add: delete_eq) lemma dom_delete_subset: "fst ` set (delete k al) \ fst ` set al" by (auto simp add: delete_eq) lemma delete_update_same: "delete k (update k v al) = delete k al" by (induct al) simp_all lemma delete_update: "k \ l \ delete l (update k v al) = update k v (delete l al)" by (induct al) simp_all lemma delete_twist: "delete x (delete y al) = delete y (delete x al)" by (simp add: delete_eq conj_commute) lemma length_delete_le: "length (delete k al) \ length al" by (simp add: delete_eq) subsection \\update_with_aux\ and \delete_aux\\ qualified primrec update_with_aux :: "'val \ 'key \ ('val \ 'val) \ ('key \ 'val) list \ ('key \ 'val) list" where "update_with_aux v k f [] = [(k, f v)]" | "update_with_aux v k f (p # ps) = (if (fst p = k) then (k, f (snd p)) # ps else p # update_with_aux v k f ps)" text \ The above \<^term>\delete\ traverses all the list even if it has found the key. This one does not have to keep going because is assumes the invariant that keys are distinct. \ qualified fun delete_aux :: "'key \ ('key \ 'val) list \ ('key \ 'val) list" where "delete_aux k [] = []" | "delete_aux k ((k', v) # xs) = (if k = k' then xs else (k', v) # delete_aux k xs)" lemma map_of_update_with_aux': "map_of (update_with_aux v k f ps) k' = ((map_of ps)(k \ (case map_of ps k of None \ f v | Some v \ f v))) k'" by (induct ps) auto lemma map_of_update_with_aux: "map_of (update_with_aux v k f ps) = (map_of ps)(k \ (case map_of ps k of None \ f v | Some v \ f v))" by (simp add: fun_eq_iff map_of_update_with_aux') lemma dom_update_with_aux: "fst ` set (update_with_aux v k f ps) = {k} \ fst ` set ps" by (induct ps) auto lemma distinct_update_with_aux [simp]: "distinct (map fst (update_with_aux v k f ps)) = distinct (map fst ps)" by (induct ps) (auto simp add: dom_update_with_aux) lemma set_update_with_aux: "distinct (map fst xs) \ set (update_with_aux v k f xs) = (set xs - {k} \ UNIV \ {(k, f (case map_of xs k of None \ v | Some v \ v))})" by (induct xs) (auto intro: rev_image_eqI) lemma set_delete_aux: "distinct (map fst xs) \ set (delete_aux k xs) = set xs - {k} \ UNIV" apply (induct xs) apply simp_all apply clarsimp apply (fastforce intro: rev_image_eqI) done lemma dom_delete_aux: "distinct (map fst ps) \ fst ` set (delete_aux k ps) = fst ` set ps - {k}" by (auto simp add: set_delete_aux) lemma distinct_delete_aux [simp]: "distinct (map fst ps) \ distinct (map fst (delete_aux k ps))" proof (induct ps) case Nil then show ?case by simp next case (Cons a ps) obtain k' v where a: "a = (k', v)" by (cases a) show ?case proof (cases "k' = k") case True with Cons a show ?thesis by simp next case False with Cons a have "k' \ fst ` set ps" "distinct (map fst ps)" by simp_all with False a have "k' \ fst ` set (delete_aux k ps)" by (auto dest!: dom_delete_aux[where k=k]) with Cons a show ?thesis by simp qed qed lemma map_of_delete_aux': "distinct (map fst xs) \ map_of (delete_aux k xs) = (map_of xs)(k := None)" apply (induct xs) apply (fastforce simp add: map_of_eq_None_iff fun_upd_twist) apply (auto intro!: ext) apply (simp add: map_of_eq_None_iff) done lemma map_of_delete_aux: "distinct (map fst xs) \ map_of (delete_aux k xs) k' = ((map_of xs)(k := None)) k'" by (simp add: map_of_delete_aux') lemma delete_aux_eq_Nil_conv: "delete_aux k ts = [] \ ts = [] \ (\v. ts = [(k, v)])" by (cases ts) (auto split: if_split_asm) subsection \\restrict\\ qualified definition restrict :: "'key set \ ('key \ 'val) list \ ('key \ 'val) list" where restrict_eq: "restrict A = filter (\(k, v). k \ A)" lemma restr_simps [simp]: "restrict A [] = []" "restrict A (p#ps) = (if fst p \ A then p # restrict A ps else restrict A ps)" by (auto simp add: restrict_eq) lemma restr_conv': "map_of (restrict A al) = ((map_of al)|` A)" proof show "map_of (restrict A al) k = ((map_of al)|` A) k" for k apply (induct al) apply simp apply (cases "k \ A") apply auto done qed corollary restr_conv: "map_of (restrict A al) k = ((map_of al)|` A) k" by (simp add: restr_conv') lemma distinct_restr: "distinct (map fst al) \ distinct (map fst (restrict A al))" by (induct al) (auto simp add: restrict_eq) lemma restr_empty [simp]: "restrict {} al = []" "restrict A [] = []" by (induct al) (auto simp add: restrict_eq) lemma restr_in [simp]: "x \ A \ map_of (restrict A al) x = map_of al x" by (simp add: restr_conv') lemma restr_out [simp]: "x \ A \ map_of (restrict A al) x = None" by (simp add: restr_conv') lemma dom_restr [simp]: "fst ` set (restrict A al) = fst ` set al \ A" by (induct al) (auto simp add: restrict_eq) lemma restr_upd_same [simp]: "restrict (-{x}) (update x y al) = restrict (-{x}) al" by (induct al) (auto simp add: restrict_eq) lemma restr_restr [simp]: "restrict A (restrict B al) = restrict (A\B) al" by (induct al) (auto simp add: restrict_eq) lemma restr_update[simp]: "map_of (restrict D (update x y al)) = map_of ((if x \ D then (update x y (restrict (D-{x}) al)) else restrict D al))" by (simp add: restr_conv' update_conv') lemma restr_delete [simp]: "delete x (restrict D al) = (if x \ D then restrict (D - {x}) al else restrict D al)" apply (simp add: delete_eq restrict_eq) apply (auto simp add: split_def) proof - have "y \ x \ x \ y" for y by auto then show "[p \ al. fst p \ D \ x \ fst p] = [p \ al. fst p \ D \ fst p \ x]" by simp assume "x \ D" then have "y \ D \ y \ D \ x \ y" for y by auto then show "[p \ al . fst p \ D \ x \ fst p] = [p \ al . fst p \ D]" by simp qed lemma update_restr: "map_of (update x y (restrict D al)) = map_of (update x y (restrict (D - {x}) al))" by (simp add: update_conv' restr_conv') (rule fun_upd_restrict) lemma update_restr_conv [simp]: "x \ D \ map_of (update x y (restrict D al)) = map_of (update x y (restrict (D - {x}) al))" by (simp add: update_conv' restr_conv') lemma restr_updates [simp]: "length xs = length ys \ set xs \ D \ map_of (restrict D (updates xs ys al)) = map_of (updates xs ys (restrict (D - set xs) al))" by (simp add: updates_conv' restr_conv') lemma restr_delete_twist: "(restrict A (delete a ps)) = delete a (restrict A ps)" by (induct ps) auto subsection \\clearjunk\\ qualified function clearjunk :: "('key \ 'val) list \ ('key \ 'val) list" where "clearjunk [] = []" | "clearjunk (p#ps) = p # clearjunk (delete (fst p) ps)" by pat_completeness auto termination by (relation "measure length") (simp_all add: less_Suc_eq_le length_delete_le) lemma map_of_clearjunk: "map_of (clearjunk al) = map_of al" by (induct al rule: clearjunk.induct) (simp_all add: fun_eq_iff) lemma clearjunk_keys_set: "set (map fst (clearjunk al)) = set (map fst al)" by (induct al rule: clearjunk.induct) (simp_all add: delete_keys) lemma dom_clearjunk: "fst ` set (clearjunk al) = fst ` set al" using clearjunk_keys_set by simp lemma distinct_clearjunk [simp]: "distinct (map fst (clearjunk al))" by (induct al rule: clearjunk.induct) (simp_all del: set_map add: clearjunk_keys_set delete_keys) lemma ran_clearjunk: "ran (map_of (clearjunk al)) = ran (map_of al)" by (simp add: map_of_clearjunk) lemma ran_map_of: "ran (map_of al) = snd ` set (clearjunk al)" proof - have "ran (map_of al) = ran (map_of (clearjunk al))" by (simp add: ran_clearjunk) also have "\ = snd ` set (clearjunk al)" by (simp add: ran_distinct) finally show ?thesis . qed lemma clearjunk_update: "clearjunk (update k v al) = update k v (clearjunk al)" by (induct al rule: clearjunk.induct) (simp_all add: delete_update) lemma clearjunk_updates: "clearjunk (updates ks vs al) = updates ks vs (clearjunk al)" proof - have "clearjunk \ fold (case_prod update) (zip ks vs) = fold (case_prod update) (zip ks vs) \ clearjunk" by (rule fold_commute) (simp add: clearjunk_update case_prod_beta o_def) then show ?thesis by (simp add: updates_def fun_eq_iff) qed lemma clearjunk_delete: "clearjunk (delete x al) = delete x (clearjunk al)" by (induct al rule: clearjunk.induct) (auto simp add: delete_idem delete_twist) lemma clearjunk_restrict: "clearjunk (restrict A al) = restrict A (clearjunk al)" by (induct al rule: clearjunk.induct) (auto simp add: restr_delete_twist) lemma distinct_clearjunk_id [simp]: "distinct (map fst al) \ clearjunk al = al" by (induct al rule: clearjunk.induct) auto lemma clearjunk_idem: "clearjunk (clearjunk al) = clearjunk al" by simp lemma length_clearjunk: "length (clearjunk al) \ length al" proof (induct al rule: clearjunk.induct [case_names Nil Cons]) case Nil then show ?case by simp next case (Cons kv al) moreover have "length (delete (fst kv) al) \ length al" by (fact length_delete_le) ultimately have "length (clearjunk (delete (fst kv) al)) \ length al" by (rule order_trans) then show ?case by simp qed lemma delete_map: assumes "\kv. fst (f kv) = fst kv" shows "delete k (map f ps) = map f (delete k ps)" by (simp add: delete_eq filter_map comp_def split_def assms) lemma clearjunk_map: assumes "\kv. fst (f kv) = fst kv" shows "clearjunk (map f ps) = map f (clearjunk ps)" by (induct ps rule: clearjunk.induct [case_names Nil Cons]) (simp_all add: clearjunk_delete delete_map assms) subsection \\map_ran\\ -definition map_ran :: "('key \ 'val \ 'val) \ ('key \ 'val) list \ ('key \ 'val) list" +definition map_ran :: "('key \ 'val1 \ 'val2) \ ('key \ 'val1) list \ ('key \ 'val2) list" where "map_ran f = map (\(k, v). (k, f k v))" lemma map_ran_simps [simp]: "map_ran f [] = []" "map_ran f ((k, v) # ps) = (k, f k v) # map_ran f ps" by (simp_all add: map_ran_def) lemma dom_map_ran: "fst ` set (map_ran f al) = fst ` set al" by (simp add: map_ran_def image_image split_def) lemma map_ran_conv: "map_of (map_ran f al) k = map_option (f k) (map_of al k)" by (induct al) auto lemma distinct_map_ran: "distinct (map fst al) \ distinct (map fst (map_ran f al))" by (simp add: map_ran_def split_def comp_def) lemma map_ran_filter: "map_ran f [p\ps. fst p \ a] = [p\map_ran f ps. fst p \ a]" by (simp add: map_ran_def filter_map split_def comp_def) lemma clearjunk_map_ran: "clearjunk (map_ran f al) = map_ran f (clearjunk al)" by (simp add: map_ran_def split_def clearjunk_map) subsection \\merge\\ qualified definition merge :: "('key \ 'val) list \ ('key \ 'val) list \ ('key \ 'val) list" where "merge qs ps = foldr (\(k, v). update k v) ps qs" lemma merge_simps [simp]: "merge qs [] = qs" "merge qs (p#ps) = update (fst p) (snd p) (merge qs ps)" by (simp_all add: merge_def split_def) lemma merge_updates: "merge qs ps = updates (rev (map fst ps)) (rev (map snd ps)) qs" by (simp add: merge_def updates_def foldr_conv_fold zip_rev zip_map_fst_snd) lemma dom_merge: "fst ` set (merge xs ys) = fst ` set xs \ fst ` set ys" by (induct ys arbitrary: xs) (auto simp add: dom_update) lemma distinct_merge: "distinct (map fst xs) \ distinct (map fst (merge xs ys))" by (simp add: merge_updates distinct_updates) lemma clearjunk_merge: "clearjunk (merge xs ys) = merge (clearjunk xs) ys" by (simp add: merge_updates clearjunk_updates) lemma merge_conv': "map_of (merge xs ys) = map_of xs ++ map_of ys" proof - have "map_of \ fold (case_prod update) (rev ys) = fold (\(k, v) m. m(k \ v)) (rev ys) \ map_of" by (rule fold_commute) (simp add: update_conv' case_prod_beta split_def fun_eq_iff) then show ?thesis by (simp add: merge_def map_add_map_of_foldr foldr_conv_fold fun_eq_iff) qed corollary merge_conv: "map_of (merge xs ys) k = (map_of xs ++ map_of ys) k" by (simp add: merge_conv') lemma merge_empty: "map_of (merge [] ys) = map_of ys" by (simp add: merge_conv') lemma merge_assoc [simp]: "map_of (merge m1 (merge m2 m3)) = map_of (merge (merge m1 m2) m3)" by (simp add: merge_conv') lemma merge_Some_iff: "map_of (merge m n) k = Some x \ map_of n k = Some x \ map_of n k = None \ map_of m k = Some x" by (simp add: merge_conv' map_add_Some_iff) lemmas merge_SomeD [dest!] = merge_Some_iff [THEN iffD1] lemma merge_find_right [simp]: "map_of n k = Some v \ map_of (merge m n) k = Some v" by (simp add: merge_conv') lemma merge_None [iff]: "(map_of (merge m n) k = None) = (map_of n k = None \ map_of m k = None)" by (simp add: merge_conv') lemma merge_upd [simp]: "map_of (merge m (update k v n)) = map_of (update k v (merge m n))" by (simp add: update_conv' merge_conv') lemma merge_updatess [simp]: "map_of (merge m (updates xs ys n)) = map_of (updates xs ys (merge m n))" by (simp add: updates_conv' merge_conv') lemma merge_append: "map_of (xs @ ys) = map_of (merge ys xs)" by (simp add: merge_conv') subsection \\compose\\ qualified function compose :: "('key \ 'a) list \ ('a \ 'b) list \ ('key \ 'b) list" where "compose [] ys = []" | "compose (x # xs) ys = (case map_of ys (snd x) of None \ compose (delete (fst x) xs) ys | Some v \ (fst x, v) # compose xs ys)" by pat_completeness auto termination by (relation "measure (length \ fst)") (simp_all add: less_Suc_eq_le length_delete_le) lemma compose_first_None [simp]: "map_of xs k = None \ map_of (compose xs ys) k = None" by (induct xs ys rule: compose.induct) (auto split: option.splits if_split_asm) lemma compose_conv: "map_of (compose xs ys) k = (map_of ys \\<^sub>m map_of xs) k" proof (induct xs ys rule: compose.induct) case 1 then show ?case by simp next case (2 x xs ys) show ?case proof (cases "map_of ys (snd x)") case None with 2 have hyp: "map_of (compose (delete (fst x) xs) ys) k = (map_of ys \\<^sub>m map_of (delete (fst x) xs)) k" by simp show ?thesis proof (cases "fst x = k") case True from True delete_notin_dom [of k xs] have "map_of (delete (fst x) xs) k = None" by (simp add: map_of_eq_None_iff) with hyp show ?thesis using True None by simp next case False from False have "map_of (delete (fst x) xs) k = map_of xs k" by simp with hyp show ?thesis using False None by (simp add: map_comp_def) qed next case (Some v) with 2 have "map_of (compose xs ys) k = (map_of ys \\<^sub>m map_of xs) k" by simp with Some show ?thesis by (auto simp add: map_comp_def) qed qed lemma compose_conv': "map_of (compose xs ys) = (map_of ys \\<^sub>m map_of xs)" by (rule ext) (rule compose_conv) lemma compose_first_Some [simp]: "map_of xs k = Some v \ map_of (compose xs ys) k = map_of ys v" by (simp add: compose_conv) lemma dom_compose: "fst ` set (compose xs ys) \ fst ` set xs" proof (induct xs ys rule: compose.induct) case 1 then show ?case by simp next case (2 x xs ys) show ?case proof (cases "map_of ys (snd x)") case None with "2.hyps" have "fst ` set (compose (delete (fst x) xs) ys) \ fst ` set (delete (fst x) xs)" by simp also have "\ \ fst ` set xs" by (rule dom_delete_subset) finally show ?thesis using None by auto next case (Some v) with "2.hyps" have "fst ` set (compose xs ys) \ fst ` set xs" by simp with Some show ?thesis by auto qed qed lemma distinct_compose: assumes "distinct (map fst xs)" shows "distinct (map fst (compose xs ys))" using assms proof (induct xs ys rule: compose.induct) case 1 then show ?case by simp next case (2 x xs ys) show ?case proof (cases "map_of ys (snd x)") case None with 2 show ?thesis by simp next case (Some v) with 2 dom_compose [of xs ys] show ?thesis by auto qed qed lemma compose_delete_twist: "compose (delete k xs) ys = delete k (compose xs ys)" proof (induct xs ys rule: compose.induct) case 1 then show ?case by simp next case (2 x xs ys) show ?case proof (cases "map_of ys (snd x)") case None with 2 have hyp: "compose (delete k (delete (fst x) xs)) ys = delete k (compose (delete (fst x) xs) ys)" by simp show ?thesis proof (cases "fst x = k") case True with None hyp show ?thesis by (simp add: delete_idem) next case False from None False hyp show ?thesis by (simp add: delete_twist) qed next case (Some v) with 2 have hyp: "compose (delete k xs) ys = delete k (compose xs ys)" by simp with Some show ?thesis by simp qed qed lemma compose_clearjunk: "compose xs (clearjunk ys) = compose xs ys" by (induct xs ys rule: compose.induct) (auto simp add: map_of_clearjunk split: option.splits) lemma clearjunk_compose: "clearjunk (compose xs ys) = compose (clearjunk xs) ys" by (induct xs rule: clearjunk.induct) (auto split: option.splits simp add: clearjunk_delete delete_idem compose_delete_twist) lemma compose_empty [simp]: "compose xs [] = []" by (induct xs) (auto simp add: compose_delete_twist) lemma compose_Some_iff: "(map_of (compose xs ys) k = Some v) \ (\k'. map_of xs k = Some k' \ map_of ys k' = Some v)" by (simp add: compose_conv map_comp_Some_iff) lemma map_comp_None_iff: "map_of (compose xs ys) k = None \ (map_of xs k = None \ (\k'. map_of xs k = Some k' \ map_of ys k' = None))" by (simp add: compose_conv map_comp_None_iff) subsection \\map_entry\\ qualified fun map_entry :: "'key \ ('val \ 'val) \ ('key \ 'val) list \ ('key \ 'val) list" where "map_entry k f [] = []" | "map_entry k f (p # ps) = (if fst p = k then (k, f (snd p)) # ps else p # map_entry k f ps)" lemma map_of_map_entry: "map_of (map_entry k f xs) = (map_of xs)(k := case map_of xs k of None \ None | Some v' \ Some (f v'))" by (induct xs) auto lemma dom_map_entry: "fst ` set (map_entry k f xs) = fst ` set xs" by (induct xs) auto lemma distinct_map_entry: assumes "distinct (map fst xs)" shows "distinct (map fst (map_entry k f xs))" using assms by (induct xs) (auto simp add: dom_map_entry) subsection \\map_default\\ fun map_default :: "'key \ 'val \ ('val \ 'val) \ ('key \ 'val) list \ ('key \ 'val) list" where "map_default k v f [] = [(k, v)]" | "map_default k v f (p # ps) = (if fst p = k then (k, f (snd p)) # ps else p # map_default k v f ps)" lemma map_of_map_default: "map_of (map_default k v f xs) = (map_of xs)(k := case map_of xs k of None \ Some v | Some v' \ Some (f v'))" by (induct xs) auto lemma dom_map_default: "fst ` set (map_default k v f xs) = insert k (fst ` set xs)" by (induct xs) auto lemma distinct_map_default: assumes "distinct (map fst xs)" shows "distinct (map fst (map_default k v f xs))" using assms by (induct xs) (auto simp add: dom_map_default) end end