2006-12-30 ago removed conditional combinator;
2006-04-27 ago tuned;
2006-04-26 ago tuned;
2005-09-15 ago TableFun/Symtab: curried lookup and update;
2005-09-01 ago curried_lookup/update;
2005-06-29 ago removed obsolete (un)fold_ast2;
2005-05-17 ago tuned;
2005-03-03 ago Move towards standard functions.
2005-02-13 ago Deleted Library.option type.
2004-12-18 ago Syntax: last premise of "_bigimpl" is wrapped with "_asm", to have a hook for
2004-06-21 ago Merged in license change from Isabelle2004
2004-04-16 ago Replaced quote by Pretty.quote.
2002-01-16 ago GPLed;
2001-11-21 ago use tracing function for trace output;
2001-10-12 ago removed lookups count;
2001-01-16 ago export fold_ast etc.;
2000-07-16 ago AST translation rules no longer require constant head on LHS;
2000-05-30 ago renamed trace/stat_norm_ast to trace/stat_ast;
1998-10-20 ago simple Env replaced by Symtab;
1997-10-06 ago eliminated raise_ast;
1996-11-26 ago Eta-expansion of a function definition, for value polymorphism
1996-02-16 ago Elimination of fully-functorial style.
1995-05-26 ago changed macro expander such that patterns also match prefixes of appls;
1995-03-03 ago added CPure (curried functions) and ProtoPure (ancestor of Pure and CPure)
1994-08-12 ago updated reference to parents
1994-02-03 ago minor internal changes;
1994-01-19 ago cosmetic changes;
1993-10-04 ago lots of internal cleaning and tuning;
1993-09-16 ago Initial revision