Reasoning about Actions and Planning with Preferences Using Prioritized Default Theory

Abstract

This paper shows how action theories, expressed in an extended version of 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. This extension provides a natural framework to introduce different types of preferences in action theories-preferences between actions and preferences between final states. In particular, we demonstrate how these preferences can be expressed within extended prioritized default theory. We also discuss how this framework can be implemented in terms of answer set programming.

Planning with preferences using logic programming

“…The work presented in this paper is the natural continuation of the work we presented in (Son and Pontelli 2004a), where we rely on prioritized default theories to express limited classes of preferences between trajectories-a strict subset of the preferences covered in this paper. This work is also influenced by other works on exploiting domain-specific knowledge in planning (e.g., (Bacchus and Kabanza 2000;Dal Lago, Pistore, and Traverso 2002;Son et al 2005)), in which domain-specific knowledge is expressed as a constraint on the trajectories achieving the goal, and hence, is a hard constraint.…”