update in static_2

[helm.git] / matita / matita / contribs / lambdadelta / static_2 / syntax / teq_teq.ma

diff --git a/matita/matita/contribs/lambdadelta/static_2/syntax/teq_teq.ma b/matita/matita/contribs/lambdadelta/static_2/syntax/teq_teq.ma
new file mode 100644 (file)
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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 "static_2/syntax/teq.ma".
+
+(* SYNTACTIC EQUIVALENCE ON TERMS *******************************************)
+
+(* Main forward properties **************************************************)
+
+theorem teq_trans:
+        Transitive … teq.
+/2 width=3 by teq_repl_1/ qed-.
+(*
+theorem teq_repl_2 (R):
+        replace_2 … R teq teq.
+#R #T1 #U1 #HTU1 #T2 #HT12 #U2 #HU12
+<(teq_inv_eq … HT12) -T2 <(teq_inv_eq … HU12) -U2 //
+qed-.
+*)