- exclusion binder added in local environments

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / syntax / ext2_ext2.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/syntax/ext2_ext2.ma b/matita/matita/contribs/lambdadelta/basic_2/syntax/ext2_ext2.ma
new file mode 100644 (file)
index 0000000..9abbbc0
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/syntax/ext2_ext2.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/syntax/ext2.ma".
+
+(* EXTENSION TO BINDERS OF A RELATION FOR TERMS *****************************)
+
+(* Main properties **********************************************************)
+
+theorem ext2_trans: ∀R. Transitive … R → Transitive … (ext2 R).
+#R #HR #I1 #I #H elim H -I1 -I
+[ #I1 #J #H >(ext2_inv_unit_sn … H) -J /2 width=1 by ext2_unit/
+| #I1 #V1 #V #HV1 #J #H elim (ext2_inv_pair_sn … H) -H 
+  #V2 #HV2 #H destruct /3 width=3 by ext2_pair/
+]
+qed-.