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

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  14
  15 include "basic_2/static/sta_sta.ma".
  16 include "basic_2/computation/cpxs_lift.ma".
  17 include "basic_2/computation/fpbu.ma".
  18
  19 (* UNITARY "BIG TREE" PROPER PARALLEL COMPUTATION FOR CLOSURES **************)
  20
  21 (* Advanced properties ******************************************************)
  22
  23 lemma lstas_fpbu: ∀h,g,G,L,T1,T2,l2. ⦃G, L⦄ ⊢ T1 •*[h, l2] T2 → (T1 = T2 → ⊥) →
  24                   ∀l1. l2 ≤ l1 → ⦃G, L⦄ ⊢ T1 ▪[h, g] l1 → ⦃G, L, T1⦄ ≻[h, g] ⦃G, L, T2⦄.
  25 /4 width=5 by fpbu_cpxs, lstas_cpxs/ qed.
  26
  27 lemma sta_fpbu: ∀h,g,G,L,T1,T2,l. ⦃G, L⦄ ⊢ T1 ▪[h, g] l+1 →
  28                 ⦃G, L⦄ ⊢ T1 •[h] T2 → ⦃G, L, T1⦄ ≻[h, g] ⦃G, L, T2⦄.
  29 #h #g #G #L #T1 #T2 #l #HT1 #HT12 elim (eq_term_dec T1 T2)
  30 /3 width=5 by sta_lstas, lstas_fpbu/ #H destruct
  31 elim (sta_inv_refl_pos … HT1 … HT12)
  32 qed.