Affiliation: | 1. Warsaw University of Technology, Faculty of Mathematics and Information Science, Koszykowa 75, 00-662 Warszawa, Poland;2. Department of Applied Mathematics, Charles University, Malostranské nám. 25, 118 00 Praha 1, Czech Republic;3. Laboratoire d’Informatique Fondamentale d’Orléans, Université d’Orléans, 45067 Orléans Cedex 2, France |