src/Pure/par_tactical.ML
2015-06-06 wenzelm 2015-06-06 more tight treatment of subgoals: main goal may refer to extra variables;
2014-11-08 wenzelm 2014-11-08 optional proof context for unify operations, for the sake of proper local options;
2014-08-19 wenzelm 2014-08-19 clarified modules;