diff options
author | Jason Gross <jagro@google.com> | 2018-06-14 22:17:17 -0400 |
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committer | Jason Gross <jagro@google.com> | 2018-06-14 22:17:17 -0400 |
commit | a1289c75dcc5382b7e9cab31958fa60965f77c27 (patch) | |
tree | d8231951bacdef02d30d9daddec8ead33f25cddd /src/Util/ListUtil | |
parent | 43fa7ce9a96617aa777ef8ea15f133d80131fcad (diff) |
Add some lemmas and defs to ListUtil.FoldBool
Diffstat (limited to 'src/Util/ListUtil')
-rw-r--r-- | src/Util/ListUtil/FoldBool.v | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/Util/ListUtil/FoldBool.v b/src/Util/ListUtil/FoldBool.v index fcdc6d2e6..6cfe6734a 100644 --- a/src/Util/ListUtil/FoldBool.v +++ b/src/Util/ListUtil/FoldBool.v @@ -1,3 +1,4 @@ +Require Import Coq.Classes.Morphisms. Require Import Coq.Lists.List. Lemma fold_left_orb_true ls @@ -6,3 +7,39 @@ Proof. induction ls as [|?? IHls]; [ reflexivity | assumption ]. Qed. Lemma fold_left_orb_pull ls v : List.fold_left orb ls v = orb v (List.fold_left orb ls false). Proof. destruct v; [ apply fold_left_orb_true | reflexivity ]. Qed. + +Fixpoint fold_andb_map {A B} (f : A -> B -> bool) (ls1 : list A) (ls2 : list B) + : bool + := match ls1, ls2 with + | nil, nil => true + | nil, _ => false + | cons x xs, cons y ys => andb (f x y) (@fold_andb_map A B f xs ys) + | cons _ _, _ => false + end. +Lemma fold_andb_map_map {A B C} f g ls1 ls2 + : @fold_andb_map A B f ls1 (@List.map C _ g ls2) + = fold_andb_map (fun a b => f a (g b)) ls1 ls2. +Proof. revert ls1 ls2; induction ls1, ls2; cbn; congruence. Qed. + +Lemma fold_andb_map_map1 {A B C} f g ls1 ls2 + : @fold_andb_map A B f (@List.map C _ g ls1) ls2 + = fold_andb_map (fun a b => f (g a) b) ls1 ls2. +Proof. revert ls1 ls2; induction ls1, ls2; cbn; congruence. Qed. + +Lemma fold_andb_map_length A B f ls1 ls2 + (H : @fold_andb_map A B f ls1 ls2 = true) + : length ls1 = length ls2. +Proof. + revert ls1 ls2 H; induction ls1, ls2; cbn; intros; + rewrite ?Bool.andb_true_iff in *; + f_equal; try congruence; intuition auto. +Qed. + +Global Instance fold_andb_map_Proper {A B} + : Proper (pointwise_relation _ (pointwise_relation _ eq) ==> eq ==> eq ==> eq) (@fold_andb_map A B). +Proof. + unfold pointwise_relation. + intros f g H ls1 y ? ls2 z ?; subst y z. + revert ls2; induction ls1, ls2; cbn; try reflexivity. + apply f_equal2; eauto. +Qed. |