proposition: Lemma nth_default_of_Nth : forall n l x d, Nth n l x -> nth_default d n l = x.
proof: Proof. Proof using. introv H. induction~ H. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)