1. Department of Computer Science (DISCO), University of Milano-Bicocca, Milan, Italy.
2. Department of Social and Human Sciences, University of Bergamo, Bergamo, Italy.
3. Life Sciences Group, Centrum Wiskunde & Informatica (CWI), Amsterdam, The Netherlands.
4. ERABLE Team, INRIA, Lyon, France.
5. Department of Computer Science, University of Pisa, Pisa, Italy.