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[helm.git] / matita / contribs / RELATIONAL / ZEq / defs.ma

diff --git a/matita/contribs/RELATIONAL/ZEq/defs.ma b/matita/contribs/RELATIONAL/ZEq/defs.ma
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+
+
+include "datatypes/Zah.ma".
+include "NPlus/defs.ma".
+
+inductive ZEq: Zah \to Zah \to Prop :=
+   | zeq: \forall m1,m2,m3,m4,n.
+          (m1 + m4 == n) \to (m3 + m2 == n) \to
+          ZEq \langle m1, m2 \rangle \langle m3, m4 \rangle
+.
+
+interpretation "integer equality" 'eq x y =
+ (cic:/matita/RELATIONAL/ZEq/defs/ZEq.ind#xpointer(1/1) x y).
+