Applications of Finite-State Transducers in Natural Language Processing

This paper is a review of some of the major applications of nite-state transducers in natural-language processing ranging from morphological analysis to nite-state parsing. The analysis and generation of in ected word forms can be performed e ciently by means of lexical transducers. Such transducers can be compiled using an extended regular-expression calculus with restriction and replacement operators. These operators facilitate the description of complex linguistic phenomena involving morphological alternations and syntactic patterns. Because regular languages and relations can be encoded as nite-automata, new languages and relations can be derived from them directly by the nitestate calculus. This is a fundamental advantage over higher-level linguistic formalisms.