matita/matita/contribs/lambdadelta/basic_2/syntax/theq_tdeq.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/syntax/tdeq.ma".
  16 include "basic_2/syntax/theq.ma".
  17
  18 (* HEAD EQUIVALENCE FOR TERMS ***********************************************)
  19
  20 (* Properties with degree-based equivalence for terms ***********************)
  21
  22 lemma tdeq_theq: ∀h,o,T1,T2. T1 ≛[h, o] T2 → T1 ⩳[h, o] T2.
  23 #h #o #T1 #T2 * -T1 -T2 /2 width=3 by theq_sort, theq_pair/
  24 qed.