(** * The list of integers between 1 and n (inclusive) *)

Fixpoint until (n : nat) : Zlist :=
  match n with
  | O => Nil Z
  | S n => Cons Z (Z_of_nat (S n)) (until n)
  end.

Lemma until_ok : forall (n : nat) (x : Z), (0 < x <= Z_of_nat n)%Z -> inlist Z x (until n).