matita/matita/contribs/lambdadelta/ground_2/steps/rtc.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/constructors/tuple_4.ma".
  16 include "ground_2/notation/constructors/zerozero_0.ma".
  17 include "ground_2/notation/constructors/zeroone_0.ma".
  18 include "ground_2/notation/constructors/onezero_0.ma".
  19 include "ground_2/lib/arith.ma".
  20
  21 (* RT-TRANSITION COUNTER ****************************************************)
  22
  23 record rtc: Type[0] ≝ {
  24    ri: nat; (* Note: inner r-steps *)
  25    rs: nat; (* Note: spine r-steps *)
  26    ti: nat; (* Note: inner t-steps *)
  27    ts: nat  (* Note: spine t-steps *)
  28 }.
  29
  30 interpretation "constructor (rtc)"
  31    'Tuple ri rs ti ts = (mk_rtc ri rs ti ts).
  32
  33 interpretation "one structural step (rtc)"
  34    'ZeroZero = (mk_rtc O O O O).
  35
  36 interpretation "one r-step (rtc)"
  37    'OneZero = (mk_rtc O (S O) O O).
  38
  39 interpretation "one t-step (rtc)"
  40    'ZeroOne = (mk_rtc O O O (S O)).