1999-07-02 ago skip_proof feature 'sorry' (for quick_and_dirty mode only);
1999-06-05 ago renamed object_logic.ML to Isar/auto_bind.ML and tuned this module;
1999-06-04 ago added calculation.ML;
1999-05-15 ago tuned;
1999-04-30 ago added Isar/comment.ML;
1999-03-11 ago moved Thy/session.ML to Isar/session.ML;
1999-02-05 ago tuned;
1998-11-24 ago added isar.ML;
1998-11-16 ago structure PureIsar;
1998-11-09 ago Isar -- Intelligible Semi-Automated Reasoning for Isabelle.