X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambda-delta%2FBasic-2%2Fsubstitution%2Flift.ma;h=7526f0c4513845bfe690f44776fa7551373ff2da;hb=fd991956035d0f1b663aab48325097e53ed9e00e;hp=a5b15e1100d74da3278a51f706b50aa1bc729554;hpb=e4f11cddf44dd9bba21f689d4f56e2d00d8d7bb5;p=helm.git

diff --git a/matita/matita/contribs/lambda-delta/Basic-2/substitution/lift.ma b/matita/matita/contribs/lambda-delta/Basic-2/substitution/lift.ma
index a5b15e110..7526f0c45 100644
--- a/matita/matita/contribs/lambda-delta/Basic-2/substitution/lift.ma
+++ b/matita/matita/contribs/lambda-delta/Basic-2/substitution/lift.ma
@@ -1,15 +1,18 @@
-(*
-    ||M||  This file is part of HELM, an Hypertextual, Electronic
-    ||A||  Library of Mathematics, developed at the Computer Science
-    ||T||  Department of the University of Bologna, Italy.
-    ||I||
-    ||T||
-    ||A||  This file is distributed under the terms of the
-    \   /  GNU General Public License Version 2
-     \ /
-      V_______________________________________________________________ *)
-
-include "lambda-delta/syntax/term.ma".
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/grammar/term_weight.ma".
 
 (* RELOCATION ***************************************************************)
 
@@ -72,6 +75,12 @@ lemma lift_split: ∀d1,e2,T1,T2. ↑[d1, e2] T1 ≡ T2 → ∀d2,e1.
 ]
 qed.
 
+(* Basic forward lemmas *****************************************************)
+
+lemma tw_lift: ∀d,e,T1,T2. ↑[d, e] T1 ≡ T2 → #T1 = #T2.
+#d #e #T1 #T2 #H elim H -d e T1 T2; normalize //
+qed.
+
 (* Basic inversion lemmas ***************************************************)
 
 lemma lift_inv_refl_aux: ∀d,e,T1,T2. ↑[d, e] T1 ≡ T2 → e = 0 → T1 = T2.