Developments in Language Theory 11th International Conference, DLT 2007, Turku, Finland, July 3-6, 2007, Proceedings

This book constitutes the refereed proceedings of the 11th International Conference on Developments in Language Theory, DLT 2007, held in Turku, Finland in July 2007.
The 32 revised full papers presented together with 6 invited papers were carefully reviewed and selected from 74 submissions. All important issues in language theory are addressed including grammars, acceptors and transducers for words, trees and graphs; algebraic theories of automata; algorithmic, combinatorial and algebraic properties of words and languages; variable length codes; symbolic dynamics; cellular automata; polyominoes and multidimensional patterns; decidability questions; image manipulation and compression; efficient text algorithms; relationships to cryptography, concurrency, complexity theory and logic; bioinspired computig, and quantum computing.

Invited Talks.- On First-Order Fragments for Words and Mazurkiewicz Traces.- Quantitative Generalizations of Languages.- What Do We Know About Language Equations?.- Information Distance and Applications.- Finite Automata and the Writing of Numbers.- Descriptional Complexity of Nondeterministic Finite Automata.- Contributed Papers.- From Determinism to Non-determinism in Recognizable Two-Dimensional Languages.- Coding Partitions: Regularity, Maximality and Global Ambiguity.- Multi-letter Reversible and Quantum Finite Automata.- Approximability and Non-approximability Results in Computing the Mean Speedup of Trace Monoids.- The Dynamics of Cellular Automata in Shift-Invariant Topologies.- Two Element Unavoidable Sets of Partial Words.- Hairpin Finite Automata.- Characterizing Reduction Graphs for Gene Assembly in Ciliates.- 2-Visibly Pushdown Automata.- An Efficient Computation of the Equation -Automaton of a Regular -Expression.- An Extension of Newton’s Method to ?-Continuous Semirings.- Non-constructive Methods for Finite Probabilistic Automata.- The Unambiguity of Segmented Morphisms.- Commutation of Binary Factorial Languages.- Inapproximability of Nondeterministic State and Transition Complexity Assuming P???NP.- State Complexity of Union and Intersection of Finite Languages.- Bisimulation Minimisation for Weighted Tree Automata.- Conjunctive Grammars Can Generate Non-regular Unary Languages.- Deterministic Blow-Ups of Minimal Nondeterministic Finite Automata over a Fixed Alphabet.- Reduced Languages as ?-Generators.- Avoiding Approximate Squares.- Duplication Roots.- Complexity Theory for Splicing Systems.- Descriptional Complexity of Bounded Context-Free Languages.- Definable Transductions and Weighted Logics for Texts.- A Star Operation forStar-Free Trace Languages.- Finite Automata on Unranked and Unordered DAGs.- On Almost Periodicity Criteria for Morphic Sequences in Some Particular Cases.- A Local Balance Property of Episturmian Words.- Suffix Automata and Standard Sturmian Words.- Fine Hierarchy of Regular Aperiodic ?-Languages.- On Transition Minimality of Bideterministic Automata.