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

Lemma orb_even_odd : forall n, orb (even n) (odd n) = true.