Affiliation: | (1) Department of Mathematics, Vrije Universiteit, De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands (e-mail: bochnak@cs.vu.nl) , NL;(2) University of New Mexico, Department of Mathematics and Statistics, Albuquerque, NM 87131-1141, USA. (e-mail: kucharz@math.unm.edu) , US |