1. Department of Computer Science, University of Sheffield, Sheffield, UK. {s.konur, m.gheorghe, c.dragomir}@sheffield.ac.uk
2. Department of Computer Science, University of Bucharest, Bucharest, Romania. florentin.ipate@ifsoft.ro
3. School of Computing Science, Newcastle University, Newcastle, UK. natalio.krasnogor@newcastle.ac.uk