Vladimir Lifschitz, Wanwan Ren
This is a preliminary report on the design of a modular language for describing actions. In the new language, an action description consists of several modules; each module describes a set of interrelated fluents and actions. "Import statements" allow the user to provide references to other modules and thus characterize new fluents and actions by relating them to others, introduced earlier. This capability is essential for designing a repository of background knowledge involving actions, because descriptions of specific action domains will need to “import” parts of the repository.