matita/matita/contribs/lambdadelta/basic_2/relocation/drops_cext2.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/relocation/drops.ma".
  16
  17 (* GENERIC SLICING FOR LOCAL ENVIRONMENTS ***********************************)
  18
  19 (* Properties with the extension to binders of a context-sensitive relation *)
  20
  21 lemma cext2_d_liftable2_sn: ∀R. d_liftable2_sn … lifts R →
  22                             d_liftable2_sn … liftsb (cext2 R).
  23 #R #HR #K #I1 #I2 * -I1 -I2 #I [| #T1 #T2 #HT12 ]
  24 #b #f #L #HLK #Z1 #H
  25 [ lapply (liftsb_inv_unit_sn … H)
  26 | lapply (liftsb_inv_pair_sn … H) * #U1 #HTU1
  27 ] -H #H destruct /3 width=3 by ext2_unit, ex2_intro/
  28 elim (HR … HT12 … HLK … HTU1) -HR -b -K -T1 /3 width=3 by ext2_pair, ex2_intro/
  29 qed-.