(** * 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_nodoubles1 : forall p : nat, Prime p -> forall n : nat, n < p -> nodoubles p (until n).