matita/matita/contribs/lambdadelta/basic_2/static/lsubr_length.ma

   1 (**************************************************************************)
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   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
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   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
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  13 (**************************************************************************)
  14
  15 include "basic_2/grammar/lenv_length.ma".
  16 include "basic_2/static/lsubr.ma".
  17
  18 (* RESTRICTED REFINEMENT FOR LOCAL ENVIRONMENTS *****************************)
  19
  20 (* Forward lemmas with length for local environments ************************)
  21
  22 lemma lsubr_fwd_length: ∀L1,L2. L1 ⫃ L2 → |L2| ≤ |L1|.
  23 #L1 #L2 #H elim H -L1 -L2 /2 width=1 by O, le_S_S/
  24 qed-.