| Affiliation: | (1) Department of Mathematics and Informatics, University, Postbus 356, NL-2600 AJ Delft, The Netherlands;(2) Centre for Mathematics and Computer Science, P.O. Box 4079, NL-1009 AB Amsterdam, The Netherlands;(3) Institute of Theoretical Biology, University, Groenhovenstraat 5, NL-2311 BT Leiden, The Netherlands;(4) Department of Mathematics, Vanderbilt University, 37235 Nashville, TN, USA;(5) Centre for Mathematics and Computer Science, P.O. Box 4079, NL-1009 AB Amsterdam, The Netherlands;(6) Sonderforschungsbereich 123, Universität, Im Neuenheimer Feld 294, D-6900 Heidelberg, Federal Republic of Germany;(7) Present address: Helsinki University of Technology, SF-02150 Espoo 15, Finland |
