The theory of fuzzy sets has become known in Czechoslovakia in the early seventies. Since then, it was applied in various areas of science, engineering and economics where indeterminate concepts had to be handled. There has been a number of national semi- nars and conferences devoted to this topic. However, the International Symposium on Fuzzy Approach to Reasoning and Decision-Making, held in 1990, was the first really representative international meeting of this kind organized in Czechoslovakia. The symposium took place in the House of Scientists of the Czechoslovak Academy of Sciences in Bechyne from June 25 till 29, 1990. Its main organizer was Mining In- stitute of the Czechoslovak Academy of Sciences in Ostrava in cooperation and support of several other institutions and organizations. A crucial role in preparing of the Sym- posium was played by the working group for Fuzzy Sets and Systems which is active in the frame of the Society of Czechoslovak Mathematicians and Physicists. The organizing and program committee was headed by Dr. Vilem Novak from the Mining Institute in Ostrava. Its members (in alphabetical order) were Dr. Martin Cerny (Prague), Prof. Bla- hoslav Harman (Liptovsky Mikulas), Ema Hyklova (Prague), Prof. Zdenek Karpfsek (Brno), Jan Laub (Prague), Dr. Milan MareS - vice-chairman (Prague), Prof. Radko Mesiar (Bratislava), Dr. Jifi Nekola - vice-chairman (Prague), Daria Novakova (Os- trava), Dr. Jaroslav Ramfk (Ostrava), Prof. Dr. Beloslav Riecan (Bratislava), Dr. Jana TalaSova (Pi'erov) and Dr. Milos Vitek (Pardubice).

The papers presented at the Symposium focused mainly on two fields of interest. First, there were papers dealing with the theoretical background of fuzzy logic and with applications of fuzzy reasoning to the problems of artificial intelligence, robotics and expert systems. Second, quite a large number of papers were devoted to fuzzy approaches to modelling of decision-making situations under uncertainty and vagueness and their applications to the evaluation of alternatives, system control and optimization.Apart from that, there were also some interesting contributions from other areas, like fuzzy classifications and the use of fuzzy approaches in quantum physics.This volume contains the most valuable and interesting papers presented at the Symposium and will be of use to all those researchers interested in fuzzy set theory and its applications.