1. Computer Science, Durham University, United Kingdom and Computer Science, University of Cambridge, United Kingdom
2. École Polytechnique Fédérale de Lausanne, Switzerland
3. Univ. Picardie Jules Verne, MIS, France
4. Computer Science, University of Cambridge, United Kingdom
5. Univ. Lille, CNRS, UMR 9189 CRIStAL, France