1. Department of Systems and Control Engineering, School of Engineering, Tokyo Institute of Technology, Tokyo, Japan
2. Departement d'Informatique de l'Ecole Normale Superieure, ENS/INRIA/CNRS UMR 8548, Inria, WILLOW project, PSL Research University, Paris, France
3. Department of Computer Sciene, ETH Zurich, Zurich, Switzerland
4. Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, Czech Republic
5. Chalmers University of Technology, Gothenburg, Sweden