Module NAddProp (Import N : NAxiomsMiniSig').
Include NBaseProp N.
(** For theorems about [add] that are both valid for [N] and [Z], see [NZAdd] *)
(** Now comes theorems valid for natural numbers but not for Z *)

Theorem eq_add_succ :
forall n m, (exists p, n + m == S p) <->
(exists n', n == S n') \/ (exists m', m == S m').