- work in progress proceeds for the new definition of voids ...

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / syntax / voids_voids.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/syntax/voids_voids.ma b/matita/matita/contribs/lambdadelta/basic_2/syntax/voids_voids.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 "basic_2/syntax/voids.ma".
+
+(* EQUIVALENCE FOR LOCAL ENVIRONMENTS UP TO EXCLUSION BINDERS ***************)
+
+(* Main inversion lemmas ****************************************************)
+
+theorem voids_inj: ∀L1,L2,n1,n2. ⓧ*[n1]L1 ≋ ⓧ*[n2]L2 →
+                   ∀m1,m2. ⓧ*[m1]L1 ≋ ⓧ*[m2]L2 →
+                   ∧∧ n1 = m1 & n2 = m2.