- exclusion binder in local environments allows to complete lfsx_lfsx !

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

diff --git a/matita/matita/contribs/lambdadelta/basic_2/rt_computation/csx_lfdeq.ma b/matita/matita/contribs/lambdadelta/basic_2/rt_computation/csx_lfdeq.ma
new file mode 100644 (file)
index 0000000..67e6361
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/rt_computation/csx_lfdeq.ma
@@ -0,0 +1,35 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/rt_transition/cpx_lfdeq.ma".
+include "basic_2/rt_computation/csx_csx.ma".
+
+(* STRONGLY NORMALIZING TERMS FOR UNCOUNTED PARALLEL RT-TRANSITION **********)
+
+(* Properties with degree-based equivalence for local environments **********)
+
+(* Basic_2A1: uses: csx_lleq_conf *)
+lemma csx_lfdeq_conf: ∀h,o,G,L1,T. ⦃G, L1⦄ ⊢ ⬈*[h, o] 𝐒⦃T⦄ →
+                      ∀L2. L1 ≡[h, o, T] L2 → ⦃G, L2⦄ ⊢ ⬈*[h, o] 𝐒⦃T⦄.
+#h #o #G #L1 #T #H
+@(csx_ind … H) -T #T1 #_ #IH #L2 #HL12
+@csx_intro #T2 #HT12 #HnT12
+elim (lfdeq_cpx_trans … HL12 … HT12) -HT12
+/5 width=4 by cpx_lfdeq_conf_sn, csx_tdeq_trans, tdeq_trans/
+qed-.
+
+(* Basic_2A1: uses: csx_lleq_conf *)
+lemma csx_lfdeq_trans: ∀h,o,L1,L2,T. L1 ≡[h, o, T] L2 →
+                       ∀G. ⦃G, L2⦄ ⊢ ⬈*[h, o] 𝐒⦃T⦄ → ⦃G, L1⦄ ⊢ ⬈*[h, o] 𝐒⦃T⦄.
+/3 width=3 by csx_lfdeq_conf, lfdeq_sym/ qed-.