proposition: Lemma nth_default_succ : forall n x l d, nth_default d (S n) (x::l) = nth_default d n l.
proof: Proof. Proof using. introv. reflexivity. Qed.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)