milestone update in basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / rt_transition / fpbc_fpb.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/rt_transition/fpbc_fpb.ma b/matita/matita/contribs/lambdadelta/basic_2/rt_transition/fpbc_fpb.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 "static_2/static/feqx_feqx.ma".
+include "basic_2/rt_transition/fpbc.ma".
+
+(* PROPER PARALLEL RST-TRANSITION FOR CLOSURES ******************************)
+
+(* Inversrion lemmas with parallel rst-transition for closures **************)
+
+(* Basic_2A1: uses: fpbq_ind_alt *)
+lemma fpb_inv_fpbc:
+      ∀G1,G2,L1,L2,T1,T2. ❪G1,L1,T1❫ ≽ ❪G2,L2,T2❫ →
+      ∨∨ ❪G1,L1,T1❫ ≅ ❪G2,L2,T2❫
+       | ❪G1,L1,T1❫ ≻ ❪G2,L2,T2❫.
+#G1 #G2 #L1 #L2 #T1 #T2 #H 
+elim (feqx_dec G1 G2 L1 L2 T1 T2)
+/4 width=1 by fpbc_intro, or_intror, or_introl/
+qed-.