Module Type NZAddOrderProp (Import NZ : NZOrdAxiomsSig').
Include NZBaseProp NZ <+ NZMulProp NZ <+ NZOrderProp NZ.
(** Subtraction *)
(** We can prove the existence of a subtraction of any number by a smaller one *)

Lemma le_exists_sub : forall n m, n<=m -> exists p, m == p+n /\ 0<=p.