matita/matita/contribs/lambdadelta/basic_2/relocation/seq_length.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/sex_length.ma".
  16 include "basic_2/relocation/seq.ma".
  17
  18 (* SYNTACTIC EQUIVALENCE FOR SELECTED LOCAL ENVIRONMENTS ********************)
  19
  20 (* Forward lemmas with length for local environments ************************)
  21
  22 (* Basic_2A1: includes: lreq_fwd_length *)
  23 lemma seq_fwd_length: ∀f,L1,L2. L1 ≡[f] L2 → |L1| = |L2|.
  24 /2 width=4 by sex_fwd_length/ qed-.