matita/matita/contribs/lambdadelta/basic_2/dynamic/shnv_aaa.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/dynamic/snv_aaa.ma".
  16 include "basic_2/dynamic/shnv.ma".
  17
  18 (* STRATIFIED HIGHER NATIVE VALIDITY FOR TERMS ******************************)
  19
  20 (* Advanced properties ******************************************************)
  21
  22 lemma snv_shnv_cast: ∀h,g,G,L,U,T. ⦃G, L⦄ ⊢ ⓝU.T ¡[h, g] → ⦃G, L⦄ ⊢ ⓝU.T ¡[h, g, 0].
  23 #h #g #G #L #U #T #H elim (snv_inv_cast … H) -H
  24 #U0 #HU #HT #HU0 #HTU0 @shnv_cast // -HT
  25 #l #H <(le_n_O_to_eq … H) -l
  26 elim (snv_fwd_da … HU) -HU /3 width=3 by cprs_scpds, scpds_div/
  27 qed.