Craig A. Knoblock, Josh D. Tenenberg, Qiang Yang
The purposes of this paper are threefold. The first is to provide a crisp formalization of ABSTRIPS-style abstraction, since the lack of such formalizations has made it difficult to ascertain the uses and value of this type of abstraction in previous research. Second, we define the refinement relationship between solutions at different levels of the abstraction hierarchy. Such definitions are crucial to developing efficient search strategies with this type of hierarchical planning. And third, we provide a restriction on the abstraction mapping that provides a criterion for generating useful abstractions.