- local environment refinement for the first recursive lemma on validity preservation

[helm.git] / matita / matita / contribs / lambda_delta / basic_2 / etc / lsubsv / lsubsv_ssta.etc

diff --git a/matita/matita/contribs/lambda_delta/basic_2/etc/lsubsv/lsubsv_ssta.etc b/matita/matita/contribs/lambda_delta/basic_2/etc/lsubsv/lsubsv_ssta.etc
new file mode 100644 (file)
index 0000000..1e5b5fd
--- /dev/null
+++ b/matita/matita/contribs/lambda_delta/basic_2/etc/lsubsv/lsubsv_ssta.etc
@@ -0,0 +1,24 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/computation/xprs_lsubss.ma".
+include "basic_2/dynamic/lsubsv.ma".
+
+(* LOCAL ENVIRONMENT REFINEMENT FOR STRATIFIED NATIVE VALIDITY **************)
+
+(* Properties on stratified native type assignment **************************)
+
+axiom lsubsv_ssta_trans: ∀h,g,L2,T,U2,l. ⦃h, L2⦄ ⊢ T •[g,l] U2 →
+                         ∀L1. h ⊢ L1 ⊩:⊑[g] L2 →
+                         ∃∃U1. L1 ⊢ U2 ⬌* U1 & ⦃h, L1⦄ ⊢ T •[g,l] U1.