The CLASSIC knowledge representation system : guiding principles and implementation rationale

Abstract

Our work on the CLASSIC knowledge representation system covers a broad range from theory to practice. While CLASSIC was implemented primarily to provide a simple, easy to learn and use, locally available tool for a relatively limited set of applications, it has a substantial theoretical foundation, based on a formal "terminological" logic. The logical foundation provides the semantics of a term description language, which is used to define structured concepts and make assertions about individuals in a knowledge base. These concepts and individuals are organized into a generalization hierarchy by classification and subsumption algorithms. The CLASSIC system explores the expressiveness vs. tractability tradeoff, driven by concerns of usefulness and usability in several real applications. Within this context, it embodies our views of what a knowledge representation system should