2006-01-03 ago added implementation manual;
2004-12-06 ago add latex sugar
2004-11-17 ago removed Exercises document (available on separate web site now)
2004-04-16 ago add locales
2004-03-29 ago include exercises again
2004-03-29 ago put in sections, reorganized, removed intro to isabelle
2003-05-12 ago added isar-overview
2003-03-01 ago added exercises
2000-07-04 ago tuned;
1999-07-19 ago added isar-ref;
1999-05-04 ago updated;
1998-08-27 ago made tutorial first;
1998-08-26 ago fixed tutorial;
1998-08-26 ago added HOL tutorial;
1997-05-12 ago added system, ind_defs, axclass;
1996-12-09 ago Contents - list of available documentation;