Metaphysics of Planning Domain Descriptions

Domain models for sequential decision making typically represent abstract versions of real-world systems. In practice, such representations are compact, easy to maintain, and affort faster solution times. Unfortunately, as we show in this paper, simple ways of abstracting solvable real-world problems may lead to models whose solutions are incorrect with respect to the real-world problem. There is some evidence that such limitations have restricted the applicability of SDM technology in the real world, as is apparent in the case of task and motion planning in robotics. We show that the situation can be ameliorated by a combination of increased expressive power---for example, allowing angelic nondeterminism in action effects---and new kinds of algorithmic approaches designed to produce correct solutions from initially incorrect or non-Markovian abstract models.