matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv_cpcs.ma

   1 (**************************************************************************)
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   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
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  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
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  14
  15 include "basic_2/rt_computation/csx_aaa.ma".
  16 include "basic_2/rt_equivalence/cpcs_csx.ma".
  17 include "basic_2/dynamic/cnv_aaa.ma".
  18
  19 (* CONTEXT-SENSITIVE NATIVE VALIDITY FOR TERMS ******************************)
  20
  21 (* Properties with r-equivalence ********************************************)
  22
  23 lemma cnv_cpcs_dec (a) (h) (G) (L):
  24       ∀T1. ⦃G,L⦄ ⊢ T1 ![a,h] → ∀T2. ⦃G,L⦄ ⊢ T2 ![a,h] →
  25       Decidable … (⦃G,L⦄ ⊢ T1 ⬌*[h] T2).
  26 #a #h #G #L #T1 #HT1 #T2 #HT2
  27 elim (cnv_fwd_aaa … HT1) -HT1 #A1 #HA1
  28 elim (cnv_fwd_aaa … HT2) -HT2 #A2 #HA2
  29 /3 width=2 by csx_cpcs_dec, aaa_csx/
  30 qed-.