Library Coq.setoid_ring.Rings_Z
Require Export Cring.
Require Export Integral_domain.
Require Export Ncring_initial.
Require Export Omega.
Instance Zcri: (Cring (Rr:=Zr)).
red. exact Z.mul_comm. Defined.
Lemma Z_one_zero: 1%Z <> 0%Z.
omega.
Qed.
Instance Zdi : (Integral_domain (Rcr:=Zcri)).
constructor.
exact Zmult_integral. exact Z_one_zero. Defined.