2010-05-03 ago renamed ProofContext.init to ProofContext.init_global to emphasize that this is not the real thing;
2010-04-26 ago eliminanated some unreferenced identifiers;
2010-04-11 ago Thm.add_axiom/add_def: return internal name of foundational axiom;
2010-03-21 ago tuned whitespace
2010-02-15 ago clarifed type
2009-11-13 ago modernized structure Local_Theory;
2009-11-08 ago adapted Generic_Data, Proof_Data;
2009-08-15 ago additional checkpoints avoid problems in error situations
2009-07-30 ago improved handling of parameters
2009-07-17 ago tuned/modernized Envir.subst_XXX;
2009-06-17 ago uncheck is liberal wrt. semityped terms
2009-03-13 ago coherent binding policy with primitive target operations
2009-01-21 ago removed Ids;
2009-01-21 ago binding replaces bstring
2008-06-19 ago ProofContext.abbrev_mode;
2008-05-18 ago moved global pretty/string_of functions from Sign to Syntax;
2008-04-22 ago proper abbreviations in class
2008-04-10 ago improvements are strict
2008-04-02 ago tuned
2008-03-12 ago better improvement in instantiation target
2008-03-10 ago tuned
2008-03-07 ago generic improvable syntax for targets
2008-01-08 ago refined overloading target
2007-12-11 ago continued
2007-12-05 ago improved
2007-12-03 ago overloading target