Expressing User Intent in Planning by Instance Rewriting

Classical planning is the problem of synthesizing an executable sequence of actions to achieve the given goal from the given completely-specified initial state, assuming perfect perception, deterministic actions, and a static and fullyobservable environment. Domain-specific knowledge can be specified to improve the quality of plans or control search in plan synthesis or express user intent to get plans meeting a user’s constraints. In this paper we identify many constraints about occurrence of actions in plans, their ordering, and achievement of subgoals, which can be enforced without modifying a classical planner.