(************************************************************************)
(*         *      The Rocq Prover / The Rocq Development Team           *)
(*  v      *         Copyright INRIA, CNRS and contributors             *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)
Local Open Scope R_scope.

Lemma IZR_eq : forall z1 z2:Z, z1 = z2 -> IZR z1 = IZR z2.
Ltac discrR :=
try
match goal with
|  |- (?X1 <> ?X2) =>
repeat
rewrite <- plus_IZR ||
rewrite <- mult_IZR ||
rewrite <- Ropp_Ropp_IZR || rewrite Z_R_minus;
apply eq_IZR_contrapositive; try discriminate
end.