2001-12-05 ago simplified NetRules;
2001-11-28 ago theory data: removed obsolete finish method;
2001-11-09 ago theory data: finish method;
2001-11-08 ago make SML/XL of NJ happy;
2001-11-05 ago pretty/print functions with context;
2001-10-16 ago allow empty set/type name;
2001-10-15 ago tuned NetRules;
2001-10-12 ago removed get_cases, get_induct;
2001-10-04 ago tuned print operation;
2001-10-03 ago Isar/induct_attrib.ML;
2001-10-03 ago moved HOL/Tools/induct_attrib.ML to Pure/Isar/induct_attrib.ML;