Terminological Systems Revisited: Terminology = Schema + Views

Traditionally, the core of a Termino-logical Knowledge Representation System (TKRS) consists of a so-called TBox, where concepts are introduced, and an ABox, where facts about individuals are stated in terms of these concepts. This design has a drawback because in most applications the TBox has to meet two functions at a time: on the one hand, similar to a database schema, framelike structures with typing information are introduced through primitive concepts and primitive roles; on the other hand, views on the objects in the knowledge base are provided through de-ned concepts. We propose to account for this conceptual separation by partitioning the TBox into two components for primitive and deened concepts, which we call the schema and the view part. We envision the two parts to diier with respect to the language for concepts , the statements allowed, and the semantics. We argue that by this separation we achieve more conceptual clarity about the role of primitive and deened concepts and the semantics of terminological cycles. Moreover, three case studies show the computational beneets to be gained from the reened architecture.