1997-04-02 paulson 1997-04-02 Now tests for essential ancestors (Lfp or Gfp)
1996-11-28 paulson 1996-11-28 Replaced map...~~ by
1996-01-30 clasohm 1996-01-30 expanded tabs
1995-12-08 paulson 1995-12-08 Improved error message, suggesting addition of type constraints if occurrences of the recursive set remain in the fixedpoint definition.
1995-07-25 lcp 1995-07-25 Changed comments
1995-03-03 clasohm 1995-03-03 new version of HOL with curried function application