The Framework of Knowledge Representation and Its Retrieval in LGS - Literature Guide System

This paper describes the framework of knowledge representation and the techniques for information retrieval in a program called LCS (the Literature Guide System). LGS will answer questions about scientific literatures in natural language. Model theoretic approach is employed to represent the meanings of sentences in the abstracts of literatures. The knowledge base is a set of interpreted logical formulas, and is partitioned into possible worlds, User's own view to the knowledge base can be incorporated into objects called script frames. A script frame is defined in terms of logical formulas. A query to the knowledge base is presented as a pattern. A list containing all items which match the pattern will be returned as the result. A set of rules for pattern matching are defined in terms of logic, and are designed so as to cover the cases of paraphrases and categorical implications. LGS is composed of an accommodator, a retriever, and a natural language interface. It is under development on the personal LISP system.