proposition: Lemma Forall2_Nth_inv : forall P r s n x y, Forall2 P r s -> Nth n r x -> Nth n s y -> P x y.
proof: Proof. Proof using. introv F N1 N2. gen n. induction~ F; introv N1 N2; inverts N1; inverts* N2. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)