proposition: Lemma Forall_impl : forall A (P P' : A -> Prop) ls, Forall P ls -> (forall x, In x ls -> P x -> P' x) -> Forall P' ls.
proof: Proof. induction 1; simpl; intuition. Qed.
imports: Coq(FunctionalExtensionality Arith Lia) Coq(Arith.Peano_dec Arith.Compare_dec) Coq(Relations.Relation_Operators) Coq(List) Chapar(Predefs)