src/HOL/UNITY/Union.thy
author paulson
Thu Aug 13 18:06:40 1998 +0200 (1998-08-13)
changeset 5313 1861a564d7e2
parent 5259 86d80749453f
child 5584 aad639e56d4e
permissions -rw-r--r--
Constrains, Stable, Invariant...more of the substitution axiom, but Union
does not work well with them
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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 set, 'a => 'b program] => 'b program
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    "JOIN I prg == (|Init = INT i:I. Init (prg i),
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	           Acts = UN  i:I. Acts (prg i)|)"
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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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syntax
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  "@JOIN"      :: [pttrn, 'a set, 'b set] => 'b set  ("(3JN _:_./ _)" 10)
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translations
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  "JN x:A. B"   == "JOIN A (%x. B)"
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end