(** ** Remaining constants not defined in Stdlib.Init.Nat *)
(** NB: Aliasing [le] is mandatory, since only a Definition can implement an interface Parameter... *)
Definition eq := @Logic.eq nat.
Definition le := Peano.le.
Definition lt := Peano.lt.
(** ** Basic specifications : pred add sub mul *)

Lemma iter_add :
forall p q (A:Type) (f:A -> A) (x:A),
iter (p+q) f x = iter p f (iter q f x).