This book constitutes the refereed proceedings of the 31st International Symposium on Mathematical Foundations of Computer Science, MFCS 2006. The book presents 62 revised full papers together with the full papers or abstracts of 7 invited talks. All current aspects in theoretical computer science and its mathematical foundations are addressed, from algorithms and data structures, to complexity, automata, semantics, logic, formal specifications, models of computation, concurrency theory, computational geometry and more.

The 34th International Symposium on Mathematical Foundations of Computer Science, MFCS2009, washeld in Novy Smokovec, High Tatras(Slovakia)during August 24-28, 2009. This volume contains 7 invited and 56 contributed papers presented at the symposium. The contributed papers were selected by the P- gram Committee out of a total of 148 submissions. MFCS 2009 was organized by the Slovak Society for Computer Science and the Faculty of Mathematics, Physics and Informatics of the Comenius Univ- sity in Bratislava. It wassupported by the EuropeanAssociation for Theoretical Computer Science. We...