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 predn_int (n : nat) : (0 < n)%N -> n.-1%:Z = n%:Z - 1.