matita/matita/contribs/lambdadelta/basic_2/syntax/ceq_ext_ceq_ext.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "basic_2/syntax/ceq_ext.ma".
  16
  17 (* CONTEXT-AWARE SYNTACTIC EQUIVALENCE FOR BINDERS **************************)
  18
  19 (* Main properties **********************************************************)
  20
  21 theorem ceq_ext_trans: ∀L1,I1,I. ceq_ext L1 I1 I →
  22                        ∀L2,I2. ceq_ext L2 I I2 → ∀L3. ceq_ext L3 I1 I2.
  23 #L1 #I1 #I * -I1 -I //
  24 #I1 #V1 #V #HV1 #L2 #Z #H elim (ext2_inv_pair_sn … H) -H //
  25 qed-.