This book constitutes the refereed proceedings of the 16th International Symposium Fundamentals of Computation Theory, FCT 2007, held in Budapest, Hungary in August 2007.

The 39 revised full papers presented together with 4 invited papers were carefully reviewed and selected from 147 submissions. The papers address all current topics in computation theory such as automata and formal languages, design and analysis of algorithms, computational and structural complexity, semantics, logic, algebra and categories in computer science, circuits and networks, learning theory, specification and verification, parallel and distributed systems, concurrency theory, cryptography and cryptograhic protocols, approximation and randomized algorithms, computational geometry, quantum computation and information, bio-inspired computation.

This book constitutes the thoroughly refereed post-conference proceedings of the 13th International Conference on Membrane Computing, CMC 2012, held in Budapest, Hungary, in August 2012. The 21 revised selected papers presented together with 6 invited lectures were carefully reviewed and selected from 25 papers presented at the conference. The book also deals with membrane systems, also called P systems, which are distributed and parallel algebraic models processing multisets of objects in a localized manner (evolution rules and evolving objects are encapsulated into compartments delimited by membranes), with an essential role played by the communication among compartments and with the environment.