2012-03-15 ago replacing ":" by "\<in>"
2012-03-06 ago mathematical symbols instead of ASCII
2011-11-20 ago eliminated obsolete "standard";
2010-03-13 ago removed old CVS Ids;
2007-10-07 ago modernized specifications;
2005-06-17 ago migrated theory headers to new format
2004-04-22 ago constdefs: proper order;
2003-01-23 ago tidying (by script)
2002-08-27 ago avoid duplicate fact bindings;
2002-07-14 ago Removal of mono.thy
2002-07-14 ago improved presentation markup
2002-07-02 ago Tidying and introduction of various new theorems
2002-06-26 ago new theorems
2002-06-24 ago new lemmas
2002-06-23 ago conversion of Sum, pair to Isar script
2002-06-22 ago converted Bool, Trancl, Rel to Isar format
2002-06-18 ago tidying
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"
1994-06-21 ago Addition of cardinals and order types, various tidying
1993-11-16 ago made pseudo theories for all ML files;
1993-09-16 ago Initial revision