src/HOL/UNITY/Union.thy
author paulson
Wed Aug 05 18:21:37 1998 +0200 (1998-08-05)
changeset 5259 86d80749453f
parent 5252 1b0f14d11142
child 5313 1861a564d7e2
permissions -rw-r--r--
Null program and a few new results
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(*  Title:      HOL/UNITY/Union.thy
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1998  University of Cambridge
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Unions of programs
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From Misra's Chapter 5: Asynchronous Compositions of Programs
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*)
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Union = SubstAx + FP +
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constdefs
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   Join :: ['a program, 'a program] => 'a program
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    "Join prgF prgG == (|Init = Init prgF Int Init prgG,
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			 Acts = Acts prgF Un Acts prgG|)"
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   Null :: 'a program
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    "Null == (|Init = UNIV, Acts = {id}|)"
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end