Modal tableaux for reasoning about actions and plans

Abstract

In this paper we investigate tableau proof procedures for reasoning about actions and plans. Our framework is a multimodal language close to that of propositional dynamic logic, wherein we solve the frame problem by introducing the notion of dependence as a weak causal connection between actions and atoms. The tableau procedure is sound and complete for an important fragment of our language, within which all standard problems of reasoning about actions can be expressed, in particular planning tasks. Moreover, our tableaux are analytic and provide thus a decision procedure.