Installation of new simplifier for ZF/ex. The hom_ss example in misc.ML is
particularly delicate. There is a variable renaming problem in
ramsey.ML/pigeon2_lemma. In some cases, rewriting by typechecking rules
had to be replaced by setsolver type_auto_tac... because only the solver
can instantiate variables.
(* Title: HOL/lfp.thy
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1992 University of Cambridge
The Knaster-Tarski Theorem
*)
Lfp = Set +
consts lfp :: "['a set=>'a set] => 'a set"
rules
(*least fixed point*)
lfp_def "lfp(f) == Inter({u. f(u) <= u})"
end