matita/matita/contribs/lambdadelta/basic_2/reduction/fpbc_lift.ma

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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/static/ssta_ssta.ma".
  16 include "basic_2/reduction/cpx_lift.ma".
  17 include "basic_2/reduction/fpbc.ma".
  18
  19 (* "BIG TREE" PROPER PARALLEL REDUCTION FOR CLOSURES ************************)
  20
  21 (* Advanced properties ******************************************************)
  22
  23 lemma ssta_fpbc: ∀h,g,G,L,T1,T2,l. ⦃G, L⦄ ⊢ T1 ▪[h, g] l+1 →
  24                 ⦃G, L⦄ ⊢ T1 •[h, g] T2 → ⦃G, L, T1⦄ ≻[h, g] ⦃G, L, T2⦄.
  25 #h #g #G #L #T1 #T2 #l #HT1 #HT12 elim (eq_term_dec T1 T2)
  26 /3 width=5 by fpbc_cpx, ssta_cpx/ #H destruct
  27 elim (ssta_inv_refl_pos … HT1 … HT12)
  28 qed.