Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch|Department of Computer Science, ETH Zurich, Zurich, Switzerland. kay.brodersen@inf.ethz.ch