- main proof case closed in the 4th component of preservation

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / etc / lsubss / sstas_lsubss.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2/etc/lsubss/sstas_lsubss.etc b/matita/matita/contribs/lambdadelta/basic_2/etc/lsubss/sstas_lsubss.etc
new file mode 100644 (file)
index 0000000..5ec3363
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/etc/lsubss/sstas_lsubss.etc
@@ -0,0 +1,30 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/static/lsubss_ssta.ma".
+include "basic_2/unwind/sstas.ma".
+
+(* ITERATED STRATIFIED STATIC TYPE ASSIGNMENT FOR TERMS *********************)
+
+(* Properties on lenv ref for stratified type assignment ********************)
+
+lemma lsubss_sstas_trans: ∀h,g,L2,T,U. ⦃h, L2⦄ ⊢ T •*[g] U →
+                          ∀L1. h ⊢ L1 •⊑[g] L2 → ⦃h, L1⦄ ⊢ T •*[g] U.
+#h #g #L2 #T #U #H @(sstas_ind_dx … H) -T // /3 width=5/
+qed.
+
+lemma lsubss_sstas_conf: ∀h,g,L1,T,U. ⦃h, L1⦄ ⊢ T •*[g] U →
+                         ∀L2. h ⊢ L1 •⊑[g] L2 → ⦃h, L2⦄ ⊢ T •*[g] U.
+#h #g #L2 #T #U #H @(sstas_ind_dx … H) -T // /3 width=5/
+qed.