Institute of Theoretical Computer Science, University of Ulm, D-89069 Ulm, Germany. simon.gog@uni-ulm.de|Institute of Theoretical Computer Science, University of Ulm, D-89069 Ulm, Germany. simon.gog@uni-ulm.de|Institute of Theoretical Computer Science, University of Ulm, D-89069 Ulm, Germany. simon.gog@uni-ulm.de