1. Department of Software Engineering, Faculty of Mathematics and Physics, Charles University, Malostranské nám. 25 Prague, Czech Republic
2. IT4 Innovations, VŠB — Technical University of Ostrava, 17. Listopadu 15/2172, 708 33 Ostrava-Poruba, Czech Republic
3. Univ. Bordeaux, LaBRI, UMR 5800, F-33400 Talence, France
4. CNRS, LaBRI, UMR 5800, F-33400 Talence, France