matita/matita/contribs/lambdadelta/basic_2A/etc/fpa/fpa.etc

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  14
  15 include "basic_2/notation/relations/rajust_5.ma".
  16 include "basic_2/substitution/drop.ma".
  17
  18 (* AJUSTMENT ****************************************************************)
  19
  20 inductive fpa (s:bool): bi_relation lenv term ≝
  21 | fpa_fwd: ∀L,K,T,U,d,e. ⇩[s, d, e] L ≡ K → ⇧[d, e] T ≡ U → fpa s K T L U
  22 | fpa_bwd: ∀L,K,T,U,d,e. ⇩[s, d, e] L ≡ K → ⇧[d, e] T ≡ U → fpa s L U K T
  23 .
  24
  25 interpretation
  26    "ajustment (restricted closure)"
  27    'RAjust L1 T1 s L2 T2 = (fpa s L1 T1 L2 T2).
  28
  29 (* Basic properties *********************************************************)
  30
  31 lemma fpa_refl: ∀s. bi_reflexive … (fpa s).
  32 /2 width=4 by fpa_fwd/ qed.
  33
  34 lemma fpa_sym: ∀s. bi_symmetric … (fpa s).
  35 #s #L1 #L2 #T1 #T2 * /2 width=4 by fpa_fwd, fpa_bwd/
  36 qed-.