Developments in Language Theory

The main subjects of the Developments in Language Theory (DLT) conf- ence series are formal languages, automata, conventional and unconventional computation theory, and applications of automata and language theory. T- ical, but not exclusive, topics of interest include: grammars and acceptors for strings, graphs, and arrays; e?cient text algorithms; combinatorial and al- braic properties of languages; decision problems; relations to complexity theory andlogic;picturedescriptionandanalysis;cryptography;concurrency;andDNA and quantum computing. The members of the steering committee of DLT are: J. Berstel (Paris), M. Ito(Kyoto),W. Kuich(Vienna),G. P? aun(BucharestandSeville),A. Restivo (Palermo), G. Rozenberg (chair, Leiden), A. Salomaa (Turku) and W. Thomas (Aachen). The ?rst DLT conference was organized by G. Rozenberg and A. Salomaa in Turku in 1993. After this, the DLT conferences were held in every odd year: Magdeburg(1995),Thessaloniki(1997),Aachen(1999)andVienna(2001). Since 2001, a DLT conference has been organized in every odd year in Europe and in every even year outside Europe. The last two DLT conferences were organized in Kyoto, Japan in 2002 and Szeged, Hungary in 2003. The titles of the volumes of the past DLT conferences are the following: 1. Developments in Language Theory. At the Crossroads of Mathematics, C- puter Science and Biology (edited by G. Rozenberg and A. Salomaa) (1994) (World Scienti?c) 2. Developments in Language Theory II. At the Crossroads of Mathematics, Computer Science and Biology (edited by J. Dassow, G. Rozenberg and A. Salomaa) (1996) (World Scienti?c) 3. Proceedings of the Third International Conference on Developments in L- guageTheory(editedbyS.

Inhalt
Invited Papers.- Recognizable Sets of Graphs, Hypergraphs and Relational Structures: A Survey.- Some New Directions and Questions in Parameterized Complexity.- Basic Notions of Reaction Systems.- A Kleene Theorem for a Class of Communicating Automata with Effective Algorithms.- Algebraic and Topological Models for DNA Recombinant Processes.- Contributed Papers.- Regular Expressions for Two-Dimensional Languages Over One-Letter Alphabet.- On Competence in CD Grammar Systems.- The Dot-Depth and the Polynomial Hierarchy Correspond on the Delta Levels.- Input Reversals and Iterated Pushdown Automata: A New Characterization of Khabbaz Geometric Hierarchy of Languages.- On the Maximum Coefficients of Rational Formal Series in Commuting Variables.- On Codes Defined by Bio-operations.- Avoidable Sets and Well Quasi-Orders.- A Ciliate Bio-operation and Language Families.- Semantic Shuffle on and Deletion Along Trajectories.- Sturmian Graphs and a Conjecture of Moser.- P Systems Working in the Sequential Mode on Arrays and Strings.- Optimal Time and Communication Solutions of Firing Squad Synchronization Problems on Square Arrays, Toruses and Rings.- The Power of Maximal Parallelism in P Systems.- An Efficient Pattern Matching Algorithm on a Subclass of Context Free Grammars.- On the Complexity of 2-Monotone Restarting Automata.- On Left-Monotone Deterministic Restarting Automata.- On the Computation Power of Finite Automata in Two-Dimensional Environments.- The Role of the Complementarity Relation in Watson-Crick Automata and Sticker Systems.- The Boolean Closure of Linear Context-Free Languages.- Context-Sensitive Decision Problems in Groups.- Decidability and Complexity in Automatic Monoids.- Relating Tree Series Transducers and Weighted Tree Automata.- An NP-Complete Fragmentof LTL.- From Post Systems to the Reachability Problems for Matrix Semigroups and Multicounter Automata.- Words Avoiding -Powers and the ThueMorse Morphism.- On the Equivalence Problem for E-Pattern Languages Over Small Alphabets.- Complementation of Rational Sets on Countable Scattered Linear Orderings.- On the Hausdorff Measure of ?-Power Languages.- A Method for Deciding the Finiteness of Deterministic Tabled Picture Languages.- Tissue P Systems with Minimal Symport/Antiport.