Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de|Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de|Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de|Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de|Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de|Institut fuer Informatik, Ludwig-Maximilians-Universitaet Muenchen, Oettingenstrasse 67, 80538 Muenchen, Germany. friedel@informatik.uni-muenchen.de