Symbolic Merge-and-Shrink for Cost-Optimal Planning

Álvaro Torralba Arias de Reyna, Carlos Linares López, Daniel Borrajo

Abstract: Symbolic PDBs and Merge-and-Shrink (M&S) are two approaches to derive admissible heuristics for optimal planning. We present a combination of these techniques, Symbolic Merge-and-Shrink (SM&S), which uses M&S abstractions as a relaxation criterion for a symbolic backward search. Empirical evaluation shows that SM&S has the strengths of both techniques deriving heuristics at least as good as the best of them for most domains.