2012-03-06 ago mathematical symbols instead of ASCII
2010-03-13 ago removed old CVS Ids;
2007-10-07 ago modernized specifications;
2005-06-17 ago migrated theory headers to new format
2003-05-27 ago updating ZF-UNITY with Sidi's new material
2002-07-14 ago improved presentation markup
2002-06-18 ago tidying
2002-06-18 ago conversion of Fixedpt to Isar script
2002-05-21 ago converted domrange to Isar and merged with equalities
1999-01-12 ago eliminated global/local names;
1997-10-20 ago local;
1997-10-17 ago global;
1997-01-03 ago Implicit simpsets and clasets for FOL and ZF
1996-02-06 ago expanded tabs
1995-12-09 ago removed quotes from consts and syntax sections
1994-11-29 ago replaced "rules" by "defs"
1993-11-16 ago made pseudo theories for all ML files;
1993-09-16 ago Initial revision