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

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  14
  15 include "basic_2/unfold/ltpsss.ma".
  16 include "basic_2/reducibility/ltpr_ltpss.ma".
  17
  18 (* CONTEXT-FREE PARALLEL REDUCTION ON LOCAL ENVIRONMENTS ********************)
  19
  20 (* Properties on iterated parallel unfold on local environments *************)
  21
  22 lemma ltpr_ltpsss_conf: ∀L1,K1,d,e. L1 [d, e] ▶** K1 → ∀L2. L1 ➡ L2 →
  23                         ∃∃K2. L2 [d, e] ▶** K2 & K1 ➡ K2.
  24 #L1 #K1 #d #e #H @(ltpsss_ind … H) -K1 /2 width=3/
  25 #K #K1 #_ #HK1 #IHK #L2 #HL12
  26 elim (IHK … HL12) -L1 #K2 #HLK2 #HK2
  27 elim (ltpr_ltpss_conf … HK1 … HK2) -K /3 width=3/
  28 qed.