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

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  14
  15 include "basic_2/static/lsubss_ssta.ma".
  16 include "basic_2/reducibility/xpr.ma".
  17
  18 (* EXTENDED PARALLEL REDUCTION ON TERMS *************************************)
  19
  20 (* Properties on lenv ref for stratified type assignment ********************)
  21
  22 lemma lsubss_xpr_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 * [ | #l ] #HT12
  25 [ lapply (lsubss_fwd_lsubs2 … HL12) -HL12 /3 width=3/
  26 | /3 width=4/
  27 ]
  28 qed-.