Representing Actions and State Constraints in Model-Based Diagnosis

In this paper we examine an important set of representation issues which have not been addressed by the model-based diagnosis community. In particular, we examine the problem of integrating a model-based diagnosissystem description, £¥ ¤ , with a theory of action to parsimoniously represent the effect of actions on a system and the effects of system state on performing actions in the world. We employ the situation calculus, a first-order language, as our representation language. In the context of the situation calculus, £¥ ¤ presents an, often complex, set of state constraints. These state constraints implicitly define indirect effects of actions as well as indirectly imposing further preconditions on the performance of actions. As a consequence, £¥ ¤ presents further complications to addressing the frame, ramification and qualification problems. For the purposes of this paper, we examine a syntactically restricted £¥ ¤ , which commonly occurs in the axiomatization of model-based diagnosis domains. The contributions of this paper include: 1) a framework for integrating £¥ ¤ and a theory of action. 2) a procedure for compiling £¥ ¤ into a set of successor state axioms. These axioms capture the intended interpretation of £¥ ¤ , while providing a closed-form solution to the frame and ramification problems