PRC Inc.: description of the PAKTUS system used for MUC-3

The PRC Adaptive Knowledge-based Text Understanding System (PAKTUS) has been under development as a n Independent Research and Development project at PRC since 1984 . The objective is a generic system of tools , including a core English lexicon, grammar, and concept representations, for building natural language processin g (NLP) systems for text understanding. Systems built with PAKTUS are intended to generate input to knowledg e based systems or data base systems . Input to the NLP system is typically derived from an existing electroni c message stream, such as a news wire . PAKTUS supports the adaptation of the generic core to a variety of domains : JINTACCS messages, RAINFORM messages, news reports about a specific type of event, such as financia l transfers or terrorist acts, etc., by acquiring sublanguage and domain-specific grammar, words, conceptual mappings , and discourse patterns . The long-term goal is a system that can support the processing of relatively long discourse s in domains that are fairly broad with a high rate of success .