Dominance and Subsumption in Constraint-Posting Planning

By integrating a dominance prover into the plan search process, the traditional constraint-posting planning paradigm can be generalised to permit partially satisfiable goals. In this approach, the view of planning as theorem proving is retained, although the emphasis is on proving theorems about dominance relations on classes of candidate plans. Plan classes are generated by posting constraints at various levels of abstraction, then classified within a plan lattice that manages inheritance of properties and dominance characteristics. An analysis of TWEAK demonstrates how to recast existing planning ideas in this framework, providing insight into the planner's capabilities with a dominance-proving interpretation. The plan lattice representation highlights the role of plan subsumption in optimizing search.