Gfp.thy
author clasohm
Wed, 02 Nov 1994 11:50:09 +0100
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(*  Title: 	HOL/gfp.thy
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    ID:         $Id$
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    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1994  University of Cambridge
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Greatest fixed points (requires Lfp too!)
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*)
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Gfp = Lfp +
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consts gfp :: "['a set=>'a set] => 'a set"
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rules
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 (*greatest fixed point*)
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 gfp_def "gfp(f) == Union({u. u <= f(u)})"
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end