matita/matita/contribs/lambda_delta/basic_2/reducibility/xpr.ma

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  14
  15 include "basic_2/static/ssta.ma".
  16 include "basic_2/reducibility/cpr.ma".
  17
  18 (* EXTENDED PARALLEL REDUCTION ON TERMS *************************************)
  19
  20 inductive xpr (h) (g) (L) (T1) (T2): Prop ≝
  21 | xpr_cpr : L ⊢ T1 ➡ T2 → xpr h g L T1 T2
  22 | xpr_ssta: ∀l. ⦃h, L⦄ ⊢ T1 •[g, l + 1] T2 → xpr h g L T1 T2
  23 .
  24
  25 interpretation
  26    "extended parallel reduction (term)"
  27    'XPRed h g L T1 T2 = (xpr h g L T1 T2).
  28
  29 (* Basic properties *********************************************************)
  30
  31 lemma xpr_refl: ∀h,g,L. reflexive … (xpr h g L).
  32 /2 width=1/ qed.