0 Humboldt University Institute of Informatics, Warsaw University University of Bialystok, Computer Science Institute Brandenburg University at Cottbus Bialystok University of Technology, Faculty of Computer Science Institute of Mathematics, The University of Warsaw IPI PAN and University of Podlasie 1 Hung Son Nguyen Wojciech Penczek Lech Polkowski Louchka Popova-Zeugmann Humboldt University, Institut of Computer Science Holger Schlinglo Fraunhofer FIRST and Humboldt University Andrzej Skowron Warsaw UIniversity Zbigniew Suraj University of Rzeszow, Rzeszow, Marcin Szczuka Institute of Mathematics, The University of Warsaw Matthias Werner Technical University , Chemnitz Karsten Wolf Universitt Rostock