matita/matita/contribs/lambda_delta/Basic_2/unfold/delift.ma

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  14
  15 include "Basic_2/unfold/tpss.ma".
  16
  17 (* DELIFT ON TERMS **********************************************************)
  18
  19 definition delift: nat → nat → lenv → relation term ≝
  20                    λd,e,L,T1,T2. ∃∃T. L ⊢ T1 [d, e] ≫* T & ↑[d, e] T2 ≡ T.
  21
  22 interpretation "delift (term)"
  23    'TSubst L T1 d e T2 = (delift d e L T1 T2).