2006-12-05 ago more careful indexing of local facts;
2006-07-19 ago add_local: simplified interface, all frees are known'';
2006-07-04 ago added props selector;
2006-02-26 ago add_local: do_index;
2006-02-06 ago TableFun: renamed xxx_multi to xxx_list;
2005-10-28 ago added add_local/add_global;
2005-09-15 ago TableFun/Symtab: curried lookup and update;
2005-09-01 ago curried_lookup/update;
2005-07-19 ago tuned;
2005-06-20 ago OrdList.inter;
2005-05-22 ago major tuning;
2005-03-03 ago Move towards standard functions.
2004-06-21 ago Merged in license change from Isabelle2004
2002-08-27 ago thms_containing: allow "_" in specification;
2002-07-02 ago proper treatment of border cases;
2002-07-02 ago Facts indexed by consts or (some) frees.