Module Type NZParityProp
(Import A : NZOrdAxiomsSig')
(Import B : NZParity A)
(Import C : NZMulOrderProp A).
(** Morphisms *)
#[global]
Instance Even_wd : Proper (eq==>iff) Even.
#[global]
Instance odd_wd : Proper (eq==>Logic.eq) odd.
(** Evenness and oddity are dual notions *)

(** A particular case : adding by an even number *)
Lemma even_add_even : forall n m, Even m -> even (n+m) = even n.