advances on csx towards strong normalization of rt-computation ,,,

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / rt_computation / csx_drops.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/rt_computation/csx_drops.ma b/matita/matita/contribs/lambdadelta/basic_2/rt_computation/csx_drops.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/relocation/lifts_tdeq.ma".
+include "basic_2/rt_transition/cpx_drops.ma".
+include "basic_2/rt_computation/csx.ma".
+
+(* STRONGLY NORMALIZING TERMS FOR UNCOUNTED PARALLEL RT-TRANSITION **********)
+
+(* Properties with generic relocation ***************************************)
+
+(* Basic_1: was just: sn3_lift *)
+(* Basic_2A1: was just: csx_lift *)
+lemma csx_lifts: ∀h,o,G. d_liftable1 … (csx h o G).
+#h #o #G #K #T #H @(csx_ind … H) -T
+#T1 #_ #IH #b #f #L #HLK #U1 #HTU1
+@csx_intro #U2 #HU12 #HnU12
+elim (cpx_inv_lifts … HU12 … HLK … HTU1) -HU12
+/4 width=7 by tdeq_lifts_bi/
+qed-.
+
+(* Inversion lemmas with generic slicing ************************************)
+
+(* Basic_1: was just: sn3_gen_lift *)
+(* Basic_2A1: was just: csx_inv_lift *)
+lemma csx_inv_lifts: ∀h,o,G. d_deliftable1 … (csx h o G).
+#h #o #G #L #U #H @(csx_ind … H) -U
+#U1 #_ #IH #b #f #K #HLK #T1 #HTU1
+@csx_intro #T2 #HT12 #HnT12
+elim (cpx_lifts … HT12 … HLK … HTU1) -HT12
+/4 width=7 by tdeq_inv_lifts_bi/
+qed-.