milestone update in ground_2 and basic_2A

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / etc / llpx / llsx_llpx.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/etc/llpx/llsx_llpx.etc b/matita/matita/contribs/lambdadelta/basic_2A/etc/llpx/llsx_llpx.etc
new file mode 100644 (file)
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+++ b/matita/matita/contribs/lambdadelta/basic_2A/etc/llpx/llsx_llpx.etc
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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/substitution/lleq_lleq.ma".
+include "basic_2/reduction/llpx_lleq.ma".
+include "basic_2/computation/llsx.ma".
+
+(* SN EXTENDED STRONGLY NORMALIZING LOCAL ENVIRONMENTS **********************)
+
+(* Advanced properties ******************************************************)
+
+lemma llsx_llpx_trans: ∀h,g,G,L1,T,d. G ⊢ ⋕⬊*[h, g, T, d] L1 →
+                       ∀L2. ⦃G, L1⦄ ⊢ ➡[h, g, T, d] L2 → G ⊢ ⋕⬊*[h, g, T, d] L2.
+#h #g #G #L1 #T #d #H @(llsx_ind … H) -L1 #L1 #HL1 #IHL1 #L2 #HL12 @llsx_intro
+elim (lleq_dec T L1 L2 d) /4 width=4 by lleq_llpx_trans, lleq_canc_sn/
+qed-.