matita/matita/contribs/lambdadelta/ground_2/steps/rtc_shift.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 "ground_2/notation/functions/drop_1.ma".
  16 include "ground_2/steps/rtc.ma".
  17
  18 (* RT-TRANSITION COUNTER ****************************************************)
  19
  20 definition shift (r:rtc): rtc ≝ match r with
  21 [ mk_rtc ri rh ti th ⇒ 〈ri+rh, 0, ti+th, 0〉 ].
  22
  23 interpretation "shift (rtc)"
  24    'Drop r = (shift r).
  25
  26 (* Basic properties *********************************************************)
  27
  28 lemma shift_refl: ∀ri,ti. 〈ri, 0, ti, 0〉 = ↓〈ri, 0, ti, 0〉.
  29 normalize //
  30 qed.