Constrains, Stable, Invariant...more of the substitution axiom, but Union
does not work well with them
(* Title: HOL/UNITY/Union.thy
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1998 University of Cambridge
Unions of programs
From Misra's Chapter 5: Asynchronous Compositions of Programs
*)
Union = SubstAx + FP +
constdefs
JOIN :: ['a set, 'a => 'b program] => 'b program
"JOIN I prg == (|Init = INT i:I. Init (prg i),
Acts = UN i:I. Acts (prg i)|)"
Join :: ['a program, 'a program] => 'a program
"Join prgF prgG == (|Init = Init prgF Int Init prgG,
Acts = Acts prgF Un Acts prgG|)"
Null :: 'a program
"Null == (|Init = UNIV, Acts = {id}|)"
syntax
"@JOIN" :: [pttrn, 'a set, 'b set] => 'b set ("(3JN _:_./ _)" 10)
translations
"JN x:A. B" == "JOIN A (%x. B)"
end