Abstract:

In the process of grounding domain descriptions of planning tasks, symmetries in operator descriptions may lead to multiple operators which don't differ in their semantics. If the domain is not carefully designed, this may lead to thousands of copies of the same operator. We adapt symmetry reduction techniques from state-based search and deploy these techniques before the process of grounding is initiated. Results from novel IPC domains indicate that performing symmetry reduction on the domain description level reduces the number of final operators by several orders of magnitude.