- free variables innclusion (fle) encapsulates some complexity

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / static / lfxs_fle.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma
new file mode 100644 (file)
index 0000000..df8aec0
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma
@@ -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/static/frees_frees.ma".
+include "basic_2/static/fle.ma".
+include "basic_2/static/lfxs_lfxs.ma".
+
+(* GENERIC EXTENSION ON REFERRED ENTRIES OF A CONTEXT-SENSITIVE REALTION ****)
+
+(* Properties with free variables inclusion for restricted closures *********)
+
+lemma fle_lfxs_trans: ∀R,L1,T1,T2. ⦃L1, T1⦄ ⊆ ⦃L1, T2⦄ →
+                      ∀L2. L1 ⪤*[R, T2] L2 → L1 ⪤*[R, T1] L2.
+#R #L1 #T1 #T2 * #f1 #f2 #Hf1 #Hf2 #Hf12 #L2 #HL12
+/4 width=5 by lfxs_inv_frees, sle_lexs_trans, ex2_intro/
+qed-.