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

   1 (**************************************************************************)
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   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
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  10 (*       \ /        This file is distributed under the terms of the       *)
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  14
  15 include "delayed_updating/syntax/path.ma".
  16 include "delayed_updating/notation/functions/circled_times_1.ma".
  17
  18 (* STRUCTURE FOR PATH *******************************************************)
  19
  20 rec definition path_structure (p) on p ≝
  21 match p with
  22 [ list_empty     ⇒ 𝐞
  23 | list_lcons l q ⇒
  24    match l with
  25    [ label_node_d n ⇒ path_structure q
  26    | label_edge_L   ⇒ 𝗟◗path_structure q
  27    | label_edge_A   ⇒ 𝗔◗path_structure q
  28    | label_edge_S   ⇒ 𝗦◗path_structure q
  29    ]
  30 ].
  31
  32 interpretation
  33   "structure (path)"
  34   'CircledTimes p = (path_structure p).