matita/matita/contribs/lambdadelta/basic_2/etc/xpr/xprs_lsubss.etc

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  14
  15 include "basic_2/reducibility/xpr_lsubss.ma".
  16 include "basic_2/computation/xprs.ma".
  17
  18 (* EXTENDED PARALLEL COMPUTATION ON TERMS ***********************************)
  19
  20 (* Properties on lenv ref for stratified type assignment ********************)
  21
  22 lemma lsubss_xprs_trans: ∀h,g,L1,L2. h ⊢ L1 •⊑[g] L2 →
  23                          ∀T1,T2. ⦃h, L2⦄ ⊢ T1 •➡*[g] T2 → ⦃h, L1⦄ ⊢ T1 •➡*[g] T2.
  24 #h #g #L1 #L2 #HL12 #T1 #T2 #H @(xprs_ind … H) -T2 //
  25 #T #T2 #_ #HT2 #IHT1
  26 lapply (lsubss_xpr_trans … HL12 … HT2) -L2 /2 width=3/
  27 qed-.