Implementing Discrete Event Calculus with Semantic Web Technologies

The event calculus is a logical formalism that provides the ability for a software agent to understand sequences of events and how they can affect system states. We are interested in the application of this formalism to the Web at large through semantic Web languages which offer access to a continually growing body of interconnected knowledge bases. We describe a simplified version of the event calculus that deals with discrete time points, hereafter referred to as the discrete event calculus (DEC). We justify the organization of our ontology and show how it can express some DEC axioms. We discuss a software prototype that enables the construction of statements in the DEC by doing the work of the DEC axioms that cannot be expressed in SWRL. We show how our ontology can be used to define the well-known Hanks-McDermott Problem as proof of concept. We suggest how the DEC implementation could be deployed in the context of semantic Web services.