2006-10-10 ago gen_rem(s) abandoned in favour of remove / subtract
2006-09-21 ago serial numbers for types;
2006-09-15 ago renamed Term.map_term_types to Term.map_types (cf. Term.fold_types);
2006-07-11 ago replaced Term.variant(list) by Name.variant(_list);
2006-06-07 ago renamed Type.(un)varifyT to Logic.(un)varifyT;
2006-05-22 ago export raw_unifys, could_unifys;
2006-05-20 ago export raw_matches;
2006-05-16 ago more abstract interface to classes/arities;
2006-05-05 ago replaced Sorts.DOMAIN by general Sorts.CLASS_ERROR;
2006-05-02 ago tuned;
2006-04-30 ago build classes/arities: refer to operations in sorts.ML;
2006-04-25 ago added inter_sort;
2006-03-21 ago avoid polymorphic equality;
2006-03-11 ago got rid of type;
2006-02-07 ago renamed gen_duplicates to duplicates;
2006-02-06 ago TableFun: renamed xxx_multi to xxx_list;
2006-02-06 ago subsituted gen_duplicates / has_duplicates for duplicates whenever appropriate
2005-10-08 ago added could_unify;
2005-10-04 ago minor tweaks for Poplog/ML;
2005-09-20 ago slight adaptions to library changes
2005-09-15 ago TableFun/Symtab: curried lookup and update;
2005-09-01 ago curried_lookup/update;
2005-08-29 ago use AList operations;
2005-07-28 ago typ_match, unify: canonical argument order;
2005-07-19 ago tuned match, unify;
2005-07-01 ago Moved eq_type from envir.ML to type.ML
2005-06-17 ago Symtab.fold;
2005-06-11 ago name space of classes and types maintained in tsig;
2005-06-09 ago renamed cert_typ_raw to cert_typ_abbrev;
2005-06-05 ago added Type.freeze(_type);
2005-04-21 ago - Eliminated nodup_vars check.
2005-03-04 ago Removed practically all references to Library.foldr.
2005-03-03 ago Move towards standard functions.
2005-02-13 ago Deleted Library.option type.
2004-06-22 ago tuned;
2004-06-22 ago tuned certify_typ/term;
2004-06-21 ago tuned certify_typ;
2004-06-09 ago tuned messages;
2004-05-29 ago removed norm_typ; improved output; refer to Pretty.pp;
2004-05-21 ago major cleanup of tsig datastructures and extend/merge operations; fixes old bugs in classes/arities code; proper treatment of nonterminals and syntax-only types;
2002-10-21 ago Removed add_env because was too slow for large environments.
2002-01-12 ago paramify_dummies: proper treatment of maxidx;
2001-12-18 ago tuned interface of unify, param;
2001-12-14 ago varify returns newly introduced variables;
2001-11-28 ago Syntax.typ_of_term: pass intern sort fn;
2001-11-16 ago ext_tsig_classes: rebuild_tsig!!!!!
2001-02-01 ago ext_classrel: certify_class;
2000-11-18 ago export freeze_thaw_type;
2000-08-03 ago typ_no_norm;
2000-05-21 ago removed is_type_abbr;
2000-04-17 ago NameSpace.is_qualified;
2000-04-14 ago added is_type_abbr;
2000-03-30 ago tuned;
2000-03-10 ago Type.unify and Type.typ_match now use Vartab instead of association lists.
1999-09-29 ago added witness_sorts, univ_witness;
1999-08-18 ago freeze_thaw does nothing if no variables
1999-07-23 ago replaced assoc lists by Symtab.table;
1998-08-19 ago fixed param;
1998-06-25 ago defaults for free variables hide consts of same name;
1998-05-28 ago fixed error msgs;