2005-05-17 ago tuned;
2005-04-16 ago added make_gram;
2005-03-03 ago Move towards standard functions.
2005-02-13 ago Deleted Library.option type.
2004-06-21 ago Merged in license change from Isabelle2004
2004-04-16 ago Replaced quote by Pretty.quote / Library.quote, since quote now refers to Symbol.quote
2002-03-14 ago increased treshold for "this expression could be extremely ambigous" warning
2002-01-16 ago GPLed;
1999-10-27 ago symbols in (error) messages now consistently with single backslash
1999-07-10 ago more specific exn;
1999-06-25 ago branching_level = 400;
1999-01-29 ago corrected output of symbols for several (probably not all) relevant functions
1998-05-12 ago branching_level = 250;
1998-03-09 ago tuned syntax error msg;
1997-12-28 ago renamed Symtab.null to Symtab.empty;
1996-11-26 ago Eta-expansion of a function definition, for value polymorphism
1996-11-14 ago removed silly message;
1996-03-15 ago Added some functions which allow redirection of Isabelle's output
1996-02-16 ago Elimination of fully-functorial style.
1996-01-15 ago added comments
1995-07-03 ago removed debugging output
1995-07-03 ago added comments; fixed a bug; reduced memory usage slightly
1995-06-14 ago removed 'raw' productions from gram datatype; replaced mk_gram by add_prods;
1995-02-02 ago simplified elimination of chain productions
1995-01-11 ago pretty_gram: now sorts productions;
1994-12-08 ago changed Pure's grammar and the way types are converted to nonterminals
1994-11-09 ago changed warning for extremely ambiguous expressions
1994-11-03 ago added warning message
1994-10-04 ago made major changes to grammar;
1994-08-19 ago removed roots arg of extend_gram;
1994-05-26 ago "Building new grammar" message is no longer displayed by empty_gram
1994-05-19 ago lookaheads are now computed faster (during the grammar is built)
1994-05-17 ago fixed a bug in syntax_error, added "Building new grammar" message;
1994-05-13 ago syntax_error now checks precedences when computing expected tokens
1994-05-09 ago syntax_error now removes duplicate tokens in its output and doesn't
1994-05-06 ago improved syntax error:
1994-04-26 ago made a few cosmetic changes
1994-04-22 ago changed the way a grammar is generated to allow the new parser to work;
1994-02-03 ago minor internal changes;
1994-01-19 ago MAJOR INTERNAL CHANGE: extend and merge operations of syntax tables
1993-10-08 ago *** empty log message ***
1993-10-04 ago lots of internal cleaning and tuning;