matita/matita/contribs/lambdadelta/basic_2/etc/cpys/lsuby_lsuby.etc

   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/relocation/lsuby.ma".
  16
  17 (* LOCAL ENVIRONMENT REFINEMENT FOR EXTENDED SUBSTITUTION *******************)
  18
  19 (* Main properties **********************************************************)
  20
  21 theorem lsuby_trans: Transitive … lsuby.
  22 #L1 #L #H elim H -L1 -L
  23 [ #L1 #X #H lapply (lsuby_inv_atom1 … H) -H //
  24 | #I1 #I #L1 #L #V #_ #IHL1 #X #H elim (lsuby_inv_pair1 … H) -H // *
  25   #I2 #L2 #HL2 #H destruct /3 width=1 by lsuby_pair/
  26 ]
  27 qed-.