Taxonomic syntax for first order inference

Abstract

A new polynomial time decidable fragment of first order logic is identified, and a general method for using polynomial time inference procedures in knowledge representation systems is presented. The results shown in this paper indicate that a nonstandard “taxonomic” syntax is essential in constructing natural and powerful polynomial time inference procedures. The central role of taxonomic syntax in the polynomial time inference procedures provides technical support for the often-expressed intuition that knowledge is better represented in terms of taxonomic relationships than classical first order formulas. To use the procedures in a knowledge representation system, a “Socratic proof system” is defined, which is complete for first order inference and which can be used as a semi-automated interface to a first order knowledge base.