An Introduction to Formal Language Theory

This voume combines An Introduction to Formal Language Theory with issues in computational linguistics. The book begins with standard formal language material, including a discussion of regular, context-free, context sensitive, and arbitrary phrase stucture languages. This is followed by a discussion of the corresponding families of automata: finite-state, push-down, linear bounded and Turing machines. Important topics introduced along the way include closure properties, normal forms, nondeterminism, basic parsing algorithms, and the theory of computability and undecidability. Special emphasis is given to the role of algebraic techniques in formal language theory through a chapter devoted to the fixed point approach to the analysis of context-free languages. Advanced topics in parsing are also emphasized in an unusually clear and precise presentation. A unique feature of the book is the two chapter introduction to the formal theory of natural languages. Alternative schemes for representing natural language are discussed, in particular ATNs and GPSG. This book is part of the AKM Series in Theoretical Computer Science. "A Basis for Theoretical Computer Science", also in the series, should provide the necessary background for this volume intended to serve as a text for upper undergraduate and graduate level students.