(* Lemmas that DO NOT depend on CompCert or Verifiable C *)
Definition Vector_0_is_nil (T : Type) (v : Vector.t T 0) : v = Vector.nil T :=
match v with Vector.nil => eq_refl end.
intros. inversion H; split; trivial. Qed.

Lemma skipn_length:
forall {A} n (al: list A),
(length al >= n)%nat ->
(length (skipn n al) = length al - n)%nat.