Affiliation: | (1) Institute for Software Technology, Graz University of Technology, Austria;(2) Departament de Matemática Aplicada II, Univ. Poli. de Catalunya, Spain;(3) Department of Mathematics, , TU Berlin, Germany;(4) Department of Mathematics and Computer Science, , TU Eindhoven, Netherland;(5) Department of Mathematics, MIT, Cambridege, MA 02144, USA |