Affiliation: | 1 Dept. Computer Science, Palack University, Tomkova 40, CZ-779 00, Olomouc, Czech Republic. E-mail: radim.belohlavek{at}upol.cz, 2 Dept. of Mathematics, Technical University of Ostrava, 17. listopadu, CZ-708 30, Ostrava, Czech Republic. E-mail: tatana.funiokova{at}vsb.cz, 3 Dept. Computer Science, Palack University, Tomkova 40, CZ-779 00, Olomouc, Czech Republic. E-mail: vilem.vychodil{at}upol.cz |