摘要: Applications in business and industry often use expert systems to autonomously monitor and control events and processes. An important component in monitoring and controlling applications is the ability to represent temporal knowledge and to be able to reason on the basis of that knowledge. Allen’s theory of temporal intervals has often been used to represent temporal knowledge, because it offers flexibility in representing a variety of complex temporal relations among events. In this paper we show how CLIPS (C Language Integrated Production System) can be used to model temporal relations. We first use existing CLIPS constructs to develop Allen-style relations. We then present a temporal extension to CLIPS that generates the same set of relations through a call to a user-defined function. We describe the mechanics of the extension and use it in a typical workflow scenario for engineering design review. We …