Introduction to Finite-State Devices in Natural Language Processing

The theory of finite-state automata (FSA) is rich and finite-state automata techniques have been used in a wide range of domains, such as switching theory, pattern matching, pattern recognition, speech processing, hand writing recognition, optical character recognition, encryption algorithm, data compression, indexing and operating system analysis (Petri-net). In this chapter, we describe the basic notions of finite-state automata and finite-state transducers. We also describe the fundamental properties of these machines while illustrating their use. We give simple formal language examples as well as natural language examples. We also illustrate some of the main algorithms used with finite-state automata and transducers. Finite-State Devices for Natural Language Processing, Roche and Schabes (Editors), MIT Press This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Copyright c ©Mitsubishi Electric Research Laboratories, Inc., 1996 201 Broadway, Cambridge, Massachusetts 02139