This projects contains three planners:

- hsp : original version of HSP that translates each problem 
        into an executable that is run to solve the task.

- hspr: like hsp but performs search in the reverse search space
        from goal to initial situations. This search permites a
        more efficient evaluation of the heuristic function h^2.
        This planner introduces the h^2 heuristic and mutex pairs.

- hsp2: this is the planner that entered the IPC-2000 competetition.
        It is an integration of hsp and hspr. The translation and
        compilation phase is removed.