End intRing.
End intRing.
Canonical int_Ring := Eval hnf in RingType int intRing.comMixin.
Canonical int_comRing := Eval hnf in ComRingType int intRing.mulzC.
Section intRingTheory.
Implicit Types m n : int.
Local Coercion Posz : nat >-> int.

Lemma invz_out : {in [predC unitz], invz =1 id}.
Definition comMixin := ComUnitRingMixin mulVz unitzPl invz_out.