src/HOL/UNITY/Simple/Common.thy
author nipkow
Thu, 10 May 2001 17:28:40 +0200
changeset 11295 66925f23ac7f
parent 11195 65ede8dfe304
child 13785 e2fcd88be55d
permissions -rw-r--r--
improved tracing of permutative rules.

(*  Title:      HOL/UNITY/Common
    ID:         $Id$
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1998  University of Cambridge

Common Meeting Time example from Misra (1994)

The state is identified with the one variable in existence.

From Misra, "A Logic for Concurrent Programming" (1994), sections 5.1 and 13.1.
*)

Common = SubstAx + 

consts
  ftime,gtime :: nat=>nat

rules
  fmono "m <= n ==> ftime m <= ftime n"
  gmono "m <= n ==> gtime m <= gtime n"

  fasc  "m <= ftime n"
  gasc  "m <= gtime n"

constdefs
  common :: nat set
    "common == {n. ftime n = n & gtime n = n}"

  maxfg :: nat => nat set
    "maxfg m == {t. t <= max (ftime m) (gtime m)}"

end