2003-12-09  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* orderings.cc: Fixed bug returning the incorrect makespan for
	non-temporal ordering constraints.

	* plans.cc: Fixed bug causing segmentation fault when doing
	temporal planning without a planning graph.

	* plans.cc: Fixed bug creating bindings for universally quantified
	effect variables.

2003-12-05  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Using standard C++ exceptions instead of custom Exception class.

	* Added support for action costs based on duration.

	* When planning with lifted action, the planner now makes sure all
	actions are fully instantiated before returning an otherwise
	complete plan.

	* Fixed bug, reported by Ulrich Scholz, that allowed
	type-inconsistent bindings.

2003-09-18  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Added support for timed initial literals.

	* Changed from floating point to integer representation of
	temporal ordering constraints to avoid precision errors.

2003-09-08  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Changed max heuristic to makespan heuristic.

	* Added ability to add arbitrary temporal constraints to
	collection of temporal ordering constraints.

2003-09-05  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Added support for function declarations.

	* Added support for numeric initial conditions.

	* Added support for action durations that are functions of the
	action parameters (only when planning with ground actions).

2003-08-29  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Merged code for counting refinements and generating refinements.

2003-08-28  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Replaced all uses of hashing with standard sets and maps as this
	seems to make things faster.

2003-08-27  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Caching of compatible objects for faster instantiation of
	actions.

2003-07-28  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Fixed longstanding bug in handling of universally quantified
	effects.

	* Effect class now holds a single literal effect instead of lists
	of add and delete effects.

2003-07-27  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Added support for universally quantified preconditions when
	planning with lifted actions.

2003-07-21  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Added method `universal_base' to formulas to enable support for
	universally quantified preconditions when planning with lifted
	actions.

	* No longer creates new objects for identical substitutions and
	instantiations.

	* Changed name of methods <Classname>::make_<classname> to
	<Classname>::make.

	* Making sure constant equalities, inequalities, and
	quantifications are not created.

2003-07-20  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Removed time stamp from literal.  Formulas with time annotations
	are now in a Condition class.

	* Identical ground literals are represented by the same object
	allowing for faster comparison and hashing of literals.

2003-07-13  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Changed CollectibleChain to Chain.

	* New compact representation of predicates, terms, and types.

	* Removed all code related to transformational planning.

2003-03-01  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Added -S option for specifying seed to random number generator.

	* Changed -r option to mean random open condition order.

2002-12-18  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Fixed recently introduced bug that made end times equal start
	times when scheduling steps with temporal orderings.

	* Workaround for bug in Bison 1.35 that disables stack growth.

2002-12-17  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Effects with a false link condition must not be removed during
	instantiation.  It is necessary to keep them so that interference
	between concurrent actions can be properly detected.  This fixes a
	bug that was introduced in the most recent code overhaul.

2002-12-16  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Fixed memory leaks of actions, effects, and formulas.

	* All lists are now stored directly in objects, instead of being
	stored indirectly as pointers to lists.

2002-11-05  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Types are no longer required to be declared before they are used
	as supertypes.

2002-09-24  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Instead of stripping static preconditions before planning phase,
	just do not add static open conditions.  This prevents unnecessary
	duplication of objects.

2002-09-23  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Removed known memory leaks in handling of variable bindings.

	* Compute projections lazily for ActionDomain objects.

2002-09-21  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Fixed compatibility problems with GCC 3.x.

2002-09-20  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Terms and formulas are no longer instantiated when planning with
	lifted action.  This reduces memory usage.  It also means that
	there is a unique instance of every variable, which simplifies
	variable comparison.  All variables are now compared using pointer
	comparison instead of string comparison, and this leads to a
	significant performance improvement when planning with lifted
	actions.  Variables are paired with step ids when stored in
	binding constraints so that variables from the same operator but
	different instantiations can be separated.

2002-07-24  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Fixed test for durative actions in ipc3-vhpop script.

2002-07-22  Hkan L. S. Younes  <lorens@cs.cmu.edu>

	* Changed string comparisons to pointer comparisons for simple
	types, names, and literal predicates.  This both improves speed
	and reduces memory usage.
