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

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "delayed_updating/syntax/path.ma".
  16 include "delayed_updating/notation/functions/class_g_0.ma".
  17 include "ground/lib/subset.ma".
  18
  19 (* GUARD CONDITION FOR PATH *************************************************)
  20
  21 inductive pgc: predicate path ≝
  22 | pgc_empty: (𝐞) ϵ pgc
  23 | pgc_L_dx (p): p◖𝗟 ϵ pgc
  24 .
  25
  26 interpretation
  27   "guard condition (path)"
  28   'ClassG = (pgc).