proposition: Lemma fold_right_andb_true_map_filter {A} (f : A -> bool) (ls : list A) : fold_right andb true (map f (filter f ls)) = true.
proof: Proof. induction ls as [|l ls IHls]; simpl. { reflexivity. } { destruct (f l) eqn:H; simpl; rewrite ?H; simpl; assumption. } Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.ZArith.ZArith Coq.Lists.List Coq.Lists.SetoidList Coq.Bool.Bool Fiat.Common Fiat.Common.List.Operations Fiat.Common.Equality Fiat.Common.List.FlattenList Fiat.Common.LogicFacts