A computer program has been written in the LISP programming language which accepts information and answers questions presented to it in a restricted form of natural English language. The program achieves its effects by automatically creating, adding to, and searching a relational model for factual information. The purpose of this memo is to describe and explain the behavior of the program. The remainder of this section briefly describes the structure of the model. Section II presents sample conversations illustrating various features of the program, and describes the implementation of those features. Section III is a brief survey of conclusions drawn from this research. It is assumed throughout that the reader is at least somewhat familiar with the LISP programming system (and its meta-language notation), the concept of property (description) lists, and the usual notations of Mathematical Logic.
