ground_2: generic rt-transition counter

[helm.git] / matita / matita / contribs / lambdadelta / ground_2 / steps / rtc.ma

diff --git a/matita/matita/contribs/lambdadelta/ground_2/steps/rtc.ma b/matita/matita/contribs/lambdadelta/ground_2/steps/rtc.ma
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+include "ground_2/notation/constructors/tuple_4.ma".
+include "ground_2/notation/constructors/zerozero_0.ma".
+include "ground_2/notation/constructors/zeroone_0.ma".
+include "ground_2/notation/constructors/onezero_0.ma".
+include "ground_2/lib/arith.ma".
+
+(* RT-TRANSITION COUNTER ****************************************************)
+
+record rtc: Type[0] ≝ {
+   ri: nat; (* Note: inner r-steps *)
+   rh: nat; (* Note: head  r-steps *)
+   ti: nat; (* Note: inner t-steps *)
+   th: nat  (* Note: head  t-steps *)
+}.
+
+interpretation "constructor (rtc)"
+   'Tuple ri rh ti th = (mk_rtc ri rh ti th).
+
+(* Note: for one structural step *)
+definition OO: rtc ≝ 〈0, 0, 0, 0〉.
+
+interpretation "one structural step (rtc)"
+   'ZeroZero = (OO).
+
+(* Note: for one r-step *)
+definition UO: rtc ≝ 〈0, 1, 0, 0〉.
+
+interpretation "one r-step (rtc)"
+   'OneZero = (UO).
+
+(* Note: for one t-step *)
+definition OU: rtc ≝ 〈0, 0, 0, 1〉.
+
+interpretation "one t-step (rtc)"
+   'ZeroOne = (OU).