matita/matita/contribs/lambdadelta/ground/relocation/pr_tl.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
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   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "ground/notation/functions/downspoon_1.ma".
  16 include "ground/lib/stream_hdtl.ma".
  17 include "ground/relocation/pr_map.ma".
  18
  19 (* TAIL FOR PARTIAL RELOCATION MAPS *****************************************)
  20
  21 (*** tl *)
  22 definition pr_tl (f): pr_map ≝ ⇂f.
  23
  24 interpretation
  25   "tail (partial relocation maps)"
  26   'DownSpoon f = (pr_tl f).
  27
  28 (* Basic constructions ******************************************************)
  29
  30 (*** tl_push_rew *)
  31 lemma pr_tl_push (f): f = ⫰⫯f.
  32 // qed.
  33
  34 (*** tl_next_rew *)
  35 lemma pr_tl_next (f): f = ⫰↑f.
  36 // qed.
  37
  38 (* Basic eliminations *******************************************************)
  39
  40 (*** pn_split pr_map_split *)
  41 lemma pr_map_split_tl (f): ∨∨ ⫯⫰f = f | ↑⫰f = f.
  42 * * /2 width=1 by or_introl, or_intror/
  43 qed-.