PRC Inc.: description of the Paktus system used for MUC-4

BACKGROUND The PRC Adaptive Knowledge-based Text Understanding System (PAKTUS) has been unde r development as an Independent Research and Development project at PRC since 1984 . It includes a core English lexicon and grammar, a concept network, processes for applying these to lexical, syntactic, semantic, and discourse analysis, and tools that support the adaptation of the generi c core to new domains, primarily by acquiring sublanguage and domain-specific lexicon and conceptual topic patterns of interest. The lexical, syntactic, and semantic analysis components were completed before MUC-4 and required little adaptation . The discourse analysis component is new and was completed in the course of applying the system to MUC-4, although it is generic . The overall system is described in [1] . The present description concentrates on discourse analysis.