proposition: Lemma Forall2_nil_l_inv : forall P s, Forall2 P nil s -> s = nil.
proof: Proof. Proof using. introv E. inverts* E. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)