Reasoning About Actions in Prioritized Default Theory

Abstract. This paper shows how action theory in the language B can be naturally encoded using prioritized default theory. We also show how prioritized default theory can be extended to express preferences between rules and formulae. This extension provides a natural framework to introduce preferences over trajectories in B. We illustrate how these preferences can be expressed and how they can be represented within extended prioritized default theory. We also discuss how this framework can be implemented in terms of answer set programming.