Developments in Language Theory : 7th International Conference DLT 2003 Szeged Hungary July 7 11 2003 Proceedings This book constitutes the refereed proceedings of the 7th International Conference on Developments in Language Theory DLT 2003 held in Szeged Hungary in July 2003. The 27 revised full papers presented together with 7 invited papers were carefully reviewed and selected from 57 submissions. All current aspects in language theory are addressed in particular grammars acceptors and transducers for strings trees graphs arrays etc; algebraic theories for automata and languages; combinatorial properties of words and languages; formal power series; decision problems; efficient algorithms for automata and languages; and relations to complexity theory and logic picture description and analysis DNA computing quantum computing cryptography and concurrency