This volume brings together the work of several prominent researchers who have collaborated with Janusz Brzozowski, or worked in topics he developed, in the areas of regular languages, syntactic semigroups of formal languages, the dot-depth hierarchy, and formal modeling of circuit testing and software specification using automata theory.

This book constitutes the refereed proceedings of the 15th International Workshop of Descriptional Complexity of Formal Systems, DCFS 2013, held in London, ON, Canada, in July 2013. The 22 revised full papers presented together with 4 invited papers were carefully reviewed and selected from 46 submissions. The topics covered are automata, grammars, languages and other formal systems; various modes of operations and complexity measures; co-operating systems; succinctness of description of objects, state-explosion-like phenomena; circuit complexity of Boolean functions and related measures; size complexity and structural complexity of formal systems; trade-offs between computational models and mode of operation; applications of formal systems; for instance in software and hardware testing, in dialogue systems, in systems modeling or in modeling natural languages; and their complexity constraints; size or structural complexity of formal systems for modeling natural languages; complexity aspects related to the combinatorics of words; descriptional complexity in resource-bounded or structure-bounded environments; structural complexity as related to descriptional complexity; frontiers between decidability and undecidability; universality and reversibility; nature-motivated (bio-inspired) architectures and unconventional models of computing; Kolmogorov-Chaitin complexity, algorithmic information.

This book constitutes the thoroughly refereed papers of the 17th International Conference on Implementation and Application of Automata, CIAA 2012, held in Porto, Portugal, in July 2012. The 21 revised full papers presented together with 5 invited papers and 7 short papers were carefully selected from 53 submissions. The papers cover various topics such as automata applications in formal verification methods, natural language processing, pattern matching, data storage and retrieval, and bioinformatics, as well as theoretical work on automata theory.

This book constitutes the refereed proceedings of the 14th International Workshop of Descriptional Complexity of Formal Systems 2012, held in Braga, Portugal, in July 2012. The 20 revised full papers presented together with 4 invited papers were carefully reviewed and selected from 33 submissions. The topics covered are automata, grammars, languages and related systems, various measures and modes of operations (e.g., determinism and nondeterminism); trade-offs between computational models and/or operations; succinctness of description of (finite) 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; Kolmogorov complexity.

This book constitutes the proceedings of the 25th International Conference on Developments in Language Theory, DLT 2021, which was held in Porto, Portugal, during August 16-20, 2021. The conference took place in an hybrid format with both in-person and online participation.The 27 full papers included in these proceedings were carefully reviewed and selected from 48 submissions. The DLT conference series provides a forum for presenting current developments in formal languages and automata. Its scope is very general and includes, among others, the following topics and areas: 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; bio-inspired computing; quantum computing. The book also includes 3 invited talks in full paper length.