The symposia on Mathematical Foundations of Computer Science, generally known under the acronym MFCS, have been organized alternately in Poland, the Czech Republic and Slovakia since 1972. They have a well-established tradition and inter- tional recognition as an event bringing together researchers in all branches of theore- cal computer science. The previous meetings took place in Jab?onna 1972, trbske Pleso 1973; Jadwisin 1974, Marianske Lazn ?, 1975, Gda ?sk 1976, Tatranska Lomnica 1977, Zakopane 1978, Olomouc 1979, Rydzyna 1980, trbske Pleso 1981, Prague 1984, Bratislava 1986, Karlovy...