Including domain-specific reasoners with reusable ontologies

In this paper, we extend the methodology for developing intelligent systems that promotes building knowledge bases by assembling reusable ontologies and knowledge base modules from online libraries to include associating domainspecific reasoners with reusable ontologies and incorporating such reasoners into an intelligent system as part of the knowledge assembly process. The methodology is based on an existing hybrid reasoning architecture that provides an API and functional specification for special-purpose reasoners. We illustrate the methodology by describing a reusable time ontology and an associated set of domain-specific reasoners for the vocabulary of relations defined in that ontology. The ontology is designed to support large-scale knowledge system applications by providing an easily understandable, flexible, formally defined, and effective means of representing knowledge about time and the standard components and properties of calendars. The domain-specific reasoners support "telling and "asking" operations for temporal ordering relations on time points and the Allen relations on time intervals.