proposition: Lemma Vsub_nil : forall i k (h:i+k<=0), Vsub Vnil h = Vcast Vnil (Vsub_nil_aux1 h).
proof: Proof. intros. apply Vsub_nil_aux. Qed.
imports: Coq(Vector Program Structures.Equalities Morphisms) CoLoR(LogicUtil NatUtil EqUtil ListUtil BoolUtil RelUtil)