matita/matita/contribs/lambdadelta/delayed_updating/syntax/prototerm_proper.ma

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  14
  15 include "delayed_updating/syntax/path_proper.ma".
  16 include "ground/lib/subset_ext_equivalence.ma".
  17
  18 (* PROPER CONDITION FOR PROTOTERM *******************************************)
  19
  20 interpretation
  21   "proper condition (prototerm)"
  22   'PredicatePTail t = (subset_ext_p1 path ppc t).
  23
  24 (* Basic constructions ******************************************************)
  25
  26 lemma tpc_i (t):
  27       (𝐞 ⧸ϵ t) → Ꝕt.
  28 #t #Ht * //
  29 #H elim (Ht H)
  30 qed.
  31
  32 (* Basic inversions *********************************************************)
  33
  34 lemma tpc_e (t): Ꝕt → 𝐞 ϵ t → ⊥.
  35 /2 width=5 by subset_in_inv_ext_p1_dx/ qed-.