matita/matita/contribs/lambdadelta/basic_2/etc/csup/ysteps_csups.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/computation/yprs_csups.ma".
  16 include "basic_2/computation/ysteps.ma".
  17
  18 (* ITERATED STEP OF HYPER PARALLEL COMPUTATION ON CLOSURES ******************)
  19
  20 (* Properties on iterated supclosure ****************************************)
  21
  22 lemma csups_ysteps: ∀h,g,L1,L2,T1,T2. ⦃L1, T1⦄ >* ⦃L2, T2⦄ →
  23                     h ⊢ ⦃L1, T1⦄ •⭃*[g] ⦃L2, T2⦄.
  24 #h #g #L1 #L2 #T1 #T2 #H
  25 lapply (csups_fwd_cw … H) #H1
  26 @ysteps_intro /2 width=1/ -H #H2 #H3 destruct
  27 elim (lt_refl_false … H1)
  28 qed.