1. Dag Tjøstheim is Professor Emeritus, Department of Mathematics, University of Bergen, P.b. 7803, 5020 Bergen, Norway
2. Håkon Otneim is Associate Professor, Department of Business and Management Science, Norwegian School of Economics, Helleveien 30, 5045 Bergen, Norway
3. Bård Støve is Professor, Department of Mathematics, University of Bergen, P.b. 7803, 5020 Bergen, Norway