This book constitutes the refereed proceedings of the 16th International Conference on Descriptional Complexity of Formal Systems, DCFS 2014, held in Turku, Finland, in August 2014. The 27 full papers presented were carefully reviewed and selected from 35 submissions. The conference dealt with the following topics: Automata, grammars, languages and other formal systems; various modes of operation and complexity measures; trade-offs between computational models and modes of operation; succinctness of description of objects, state explosion-like phenomena; circuit complexity of Boolean functions and related measures; resource-bounded or structure-bounded environments; frontiers between decidability and undecidability; universality and reversibility; structural complexity; formal systems for applications (e.g., software reliability, software and hardware testing, modeling of natural languages); nature-motivated (bio-inspired) architectures and unconventional models of computing; complexity aspects of combinatorics on words; Kolmogorov complexity.

This book constitutes the refereed proceedings of the 9th International Conference on Combinatorics on Words, WORDS 2013, held in Turku, Finland, in September 2013 under the auspices of the EATCS. The 20 revised full papers presented were carefully reviewed and selected from 43 initial submissions. The central topic of the conference is combinatorics on words (i.e. the study of finite and infinite sequence of symbols) from varying points of view, including their combinatorial, algebraic and algorithmic aspects, as well as their applications.

This book constitutes the proceedings of the 7th International Computer Science Symposium in Russia, CSR 2012, held in Nizhny Novgorod in July 2012. The 28 full papers presented in this volume were carefully reviewed and selected from 66 submissions. CSR 2012 was one of the events of the Alan Turing Year 2012, the topics dealt with cover substantial parts of theoretical computer science and its applications.

Dedicated to Arto Salomaa, a towering figure of theoretical computer science, on the occasion of his 65th birthday, this book is a tribute to him on behalf of the theoretical computer science community. The contributions are written by internationally recognized scientists and cover most of Salomaa's many research areas. Due to its representative selection of classic and cutting edge trends in theoretical computer science, the book constitutes a comprehensive state-of-the-art survey. The contributions are in such central areas as automata theory, algorithms and complexity, and combinatorics of words. But not only that, they take up new areas such as regular sets and biocomputing. While some are survey articles of fundamental topics, most are original research papers.

The papers containedin this volume were presentedat the 5th IFIP InternationalC- ference on Theoretical Computer Science (IFIP TCS), 7-10 September 2008, Milan, Italy. TCS is a bi-annual conference.The ?rst conferenceof the series was held in Sendai (Japan, 2000), followed by Montreal (Canada, 2002), Toulouse (France, 2004) and Santiago (Chile, 2006).TCS is organizedby IFIP TC1 (Technical Committee 1: Fo- dations of Computer Science) and Working Group 2.2 of IFIP TC2 (Technical C- mittee 2: Software: Theory and Practice). TCS 2008 was part of the 20th IFIP World Computer Congress (WCC 2008), constituting the TC1 Track of WCC 2008. The contributed papers were selected from 36+45 submissions from altogether 30 countries. A total of 14+16 submissions were accepted as full papers. Papers in this volume are original contributions in two general areas: Track A: Algorithms, C- plexity and Models of Computation;and Track B: Logic, Semantics, Speci?cation and Veri?cation. The conference also included seven invited presentations, from Luca Cardelli, Thomas Ehrhard, Javier Esparza, Antonio Restivo, Tim Roughgarden, Gr- gorz Rozenberg and Avraham Trakhtman. These presentations are included (except one) in this volume. In particular, Luca Cardelli, Javier Esparza, Antonio Restivo, Tim Roughgarden and Avraham Trakhtman accepted our invitation to write full papers - lated to their talks.

The papers containedin this volume were presentedat the 5th IFIP InternationalC- ference on Theoretical Computer Science (IFIP TCS), 7-10 September 2008, Milan, Italy. TCS is a bi-annual conference.The ?rst conferenceof the series was held in Sendai (Japan, 2000), followed by Montreal (Canada, 2002), Toulouse (France, 2004) and Santiago (Chile, 2006).TCS is organizedby IFIP TC1 (Technical Committee 1: Fo- dations of Computer Science) and Working Group 2.2 of IFIP TC2 (Technical C- mittee 2: Software: Theory and Practice). TCS 2008 was part of the 20th IFIP World Computer Congress (WCC 2008), constituting the TC1 Track of WCC 2008. The contributed papers were selected from 36+45 submissions from altogether 30 countries. A total of 14+16 submissions were accepted as full papers. Papers in this volume are original contributions in two general areas: Track A: Algorithms, C- plexity and Models of Computation;and Track B: Logic, Semantics, Speci?cation and Veri?cation. The conference also included seven invited presentations, from Luca Cardelli, Thomas Ehrhard, Javier Esparza, Antonio Restivo, Tim Roughgarden, Gr- gorz Rozenberg and Avraham Trakhtman. These presentations are included (except one) in this volume. In particular, Luca Cardelli, Javier Esparza, Antonio Restivo, Tim Roughgarden and Avraham Trakhtman accepted our invitation to write full papers - lated to their talks.

This book constitutes the refereed proceedings of the 34th Conference on Current Trends in Theory and Practice of Computer Science, SOFSEM 2008, held in Novy Smokovec, Slovakia, in January 2008.

The 57 revised full papers, presented together with 10 invited contributions were carefully reviewed and selected from 162 submissions. The papers are organized in four topical tracks on foundations of computer science; computing by nature; networks, security, and cryptography; and Web technologies.

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.

This book constitutes the thoroughly refereed post-proceedings of the 5th International Workshop on Finite-State Methods in Natural Language Processing, FSMNLP 2005, held in Helsinki, Finland in September 2005.

The 24 revised full papers and 7 revised poster papers presented together with 2 invited contributions and the abstracts of 6 software demos were selected from 50 submissions and have gone through two rounds of reviewing and improvement. The papers address various topics in morphology, optimality theory, some special FSM families, weighted FSM algorithms, FSM representations, exploration, ordered structures, and surface parsing.

This Festschrift celebrates the 70th birthday of Arto Kustaa Salomaa (born in Turku, Finland on June 6, 1934), one of the most in?uential researchers in theoretical computer science. Most ofhis researchconcernstheory - he is one of the founding fathers of formal language and automata theory, but he has also made important contributions to cryptography and natural computing. His approach to research in theoretical computer science is exemplary and inspirational for his students, collaborators, andthereadersofhispapersandbooks. Forhim, theroleoftheory(incomputer science) is to discover general rules of information processing that hold within computer science and in the world around us. One should not waste time on research concerning passing artifacts (or fashionable topics of the moment) in computer science - theory should be permanently predictive, insightful, and inspiring. That's why we chose the title "Theory is Forever." The main source of his in?uence on theoretical computer science is his publi- tions. Arto is a born writer - his papers and books are always most elegant. He has a unique gift for identifying the real essence of a research problem, and then presenting it in an incisive and eloquent way. He can write about a very involved formal topic and yet avoid a (much too common) overformalization. Many of his writings are genuine jewels and belong to the classics of theoreticalcomputer science. Theyhaveinspiredgenerationsofstudentsandresearchers. Indeed, even computers as well as computer science have learned a lot from Arto's publi- tions - this is nicely illustrated by DADARA on the cover of this volume.

This book presents state of the art research in theoretical computer science and related ?elds. In particular, the following areas are discussed: automata theory, formal languages and combinatorics of words, graph transformations, Petri nets, concurrency, as well as natural and molecular computing. The articles are written by leading researchers in these areas. The writers were originally invited to contribute to this book but then the normal refereeing procedure was applied as well. All of the articles deal with some issue that has been under vigorous study during recent years. Still, the topics range from very classical ones to issues raised only two or three years ago. Both survey articles and papers attacking speci?c research problems are included. The book highlights some key issues of theoretical computer science, as they seem to us now at the beginning of the new millennium. Being a comprehensive overview of some of the most active current research in theoretical computer science, it should be of de?nite interest for all researchers in the areas covered. The topics range from basic decidability and the notion of information to graph grammars and graph transformations, and from trees and traces to aqueous algorithms, DNA encoding and self-assembly. Special e?ort has been given to lucid presentation. Therefore, the book should be of interest also for advanced students.