Developments in Language Theory

The 14th International Conference on Developments in Language Theory (DLT 2010) was held in London, Ontario, Canada on the beautiful campus of the University of Western Ontario. It was a four-day conference starting August 17 and ending August 20, 2010. The DLT conference series is one of the major international conference series in language theory. It started in Turku, Finland in 1993. Initially, it was held onceeverytwoyears. Since2001,ithasbeenheldeveryyear,oddyearsinEurope and even years in other continents. The papers submitted to DLT 2010 were from 27 countries all over the world, which include Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Finland, France, Germany, Hungary, Iceland, India, Italy, Japan, Latvia, Moldova, The Netherlands, Poland, Portugal, Russian Federation, S- vakia, South Korea, Spain, Sweden, Tunisia, UK, and the USA. Each paper was reviewed by three referees and discussed by the members of the Program C- mittee. Finally, 32 regular papers were selected by the Program Committee for presentation at the conference. There were six invited talks given at the c- ference. They were given by (in alphabetic order) Dora Giammarresi (Rome), MarkusHolzer (Giessen), OscarIbarra(Santa Barbara),Lila Kari(London,- tario), Michel Rigo (Liege), and Grzegorz Rozenber (Leiden). In addition, there were six posters on display at the conference. This volume includes all the 32 contributed papers, the papers or abstracts from the 6 invited speakers, and a 2-page abstract for each of the 6 poster papers. Wewarmlythankalltheinvitedspeakersandalltheauthorsofthesubmitted papers. Their e?orts were the bases of the success of the conference.

Invited Talks.- Reaction Systems: A Model of Computation Inspired by Biochemistry.- A Brief Excursion Inside the Class of Tiling Recognizable Two-Dimensional Languages.- The Complexity of Regular(-Like) Expressions.- On Decision Problems for Simple and Parameterized Machines.- DNA Computing and Its Implications for Theoretical Computer Science.- Numeration Systems: A Link between Number Theory and Formal Language Theory.- Regular Papers.- Algorithmic Properties of Millstream Systems.- On a Conjecture by Carpi and D'Alessandro.- Linking Algebraic Observational Equivalence and Bisimulation.- Undecidability and Hierarchy Results for Parallel Communicating Finite Automata.- Inclusion Problems for Patterns with a Bounded Number of Variables.- On the Average Number of States of Partial Derivative Automata.- On the Hybrid ?erný-Road Coloring Problem and Hamiltonian Paths.- Computing Blocker Sets for the Regular Post Embedding Problem.- Rankers over Infinite Words.- Kleene and Büchi Theorems for Weighted Automata and Multi-valued Logics over Arbitrary Bounded Lattices.- On Müller Context-Free Grammars.- Minimization of Deterministic Bottom-Up Tree Transducers.- Two-Way Unary Automata versus Logarithmic Space.- On the Periodicity of Morphic Words.- Compressed Conjugacy and the Word Problem for Outer Automorphism Groups of Graph Groups.- Using Light to Implement Parallel Boolean Algebra.- Periodicity in Tilings.- Complexity in Union-Free Regular Languages.- Schema for Parallel Insertion and Deletion.- On Schützenberger Products of Semirings.- On Language Equations XXK?=?XXL and XM?=?N over a Unary Alphabet.- Around Dot Depth Two.- Input Products for Weighted Extended Top-Down Tree Transducers.- Regular Hedge Language Factorization Revisited.- Fast Parsing forBoolean Grammars: A Generalization of Valiant's Algorithm.- On Lexicalized Well-Behaved Restarting Automata That Are Monotone.- On a Powerful Class of Non-universal P Systems with Active Membranes.- State Complexity of Prefix, Suffix, Bifix and Infix Operators on Regular Languages.- Restricted Ambiguity of Erasing Morphisms.- Automata with Extremal Minimality Conditions.- On the Existence of Minimal ?-Powers.- The Averaging Trick and the ?erný Conjecture.- Short Papers.- Pseudo-power Avoidance.- On Restricted Context-Free Grammars.- Graphs Capturing Alternations in Words.- On the Iterated Hairpin Completion.- On Lookahead Hierarchies for Monotone and Deterministic Restarting Automata with Auxiliary Symbols (Extended Abstract).- Joint Topologies for Finite and Infinite Words.