milestone update in ground_2 and basic_2A

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / etc / xpr / xprs_lsubss.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/etc/xpr/xprs_lsubss.etc b/matita/matita/contribs/lambdadelta/basic_2A/etc/xpr/xprs_lsubss.etc
new file mode 100644 (file)
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+++ b/matita/matita/contribs/lambdadelta/basic_2A/etc/xpr/xprs_lsubss.etc
@@ -0,0 +1,27 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/reducibility/xpr_lsubss.ma".
+include "basic_2/computation/xprs.ma".
+
+(* EXTENDED PARALLEL COMPUTATION ON TERMS ***********************************)
+
+(* Properties on lenv ref for stratified type assignment ********************)
+
+lemma lsubss_xprs_trans: ∀h,g,L1,L2. h ⊢ L1 •⊑[g] L2 →
+                         ∀T1,T2. ⦃h, L2⦄ ⊢ T1 •➡*[g] T2 → ⦃h, L1⦄ ⊢ T1 •➡*[g] T2.
+#h #g #L1 #L2 #HL12 #T1 #T2 #H @(xprs_ind … H) -T2 //
+#T #T2 #_ #HT2 #IHT1
+lapply (lsubss_xpr_trans … HL12 … HT2) -L2 /2 width=3/
+qed-.