matita/matita/contribs/lambdadelta/basic_2/computation/fpbs_alt.ma

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  14
  15 include "basic_2/notation/relations/btpredstaralt_8.ma".
  16 include "basic_2/computation/fpbs_fpbs.ma".
  17
  18 (* "BIG TREE" PARALLEL COMPUTATION FOR CLOSURES *****************************)
  19
  20 (* Note: alternative definition of fpbs *)
  21 definition fpbsa: ∀h. sd h → tri_relation genv lenv term ≝
  22                   λh,g,G1,L1,T1,G2,L2,T2.
  23                   ∃∃L,T. ⦃G1, L1, T1⦄ ⊃* ⦃G2, L, T⦄ & ⦃G2, L⦄ ⊢ T ➡*[h, g] T2 & ⦃G2, L⦄ ⊢ ➡*[h, g] L2.
  24
  25 interpretation "'big tree' parallel computation (closure) alternative"
  26    'BTPRedStarAlt h g G1 L1 T1 G2 L2 T2 = (fpbsa h g G1 L1 T1 G2 L2 T2).
  27
  28 (* Main inversion lemmas ****************************************************)
  29
  30 theorem fpbsa_inv_fpbs: ∀h,g,G1,G2,L1,L2,T1,T2.
  31                         ⦃G1, L1, T1⦄ ≥≥[h, g] ⦃G2, L2, T2⦄ → ⦃G1, L1, T1⦄ ≥[h, g] ⦃G2, L2, T2⦄.
  32 #h #g #G1 #G2 #L1 #L2 #T1 #T2 *
  33 /4 width=5 by fpbs_trans, fsups_fpbs, cpxs_fpbs, lpxs_fpbs/
  34 qed-.