a1 Département de Mathématiques et de Statistique, Université Laval, Québec (Québec), Canada G1K 7P4 e-mail: firstname.lastname@example.org
a2 Department of Mathematics and Statistics, Mississippi State University, Mississippi State, MS 39762, USA e-mail: email@example.com
We show that the sum and the product of two commuting operators with the single-valued extension property need not inherit this property.
(Received March 17 2006)
(Revised August 21 2006)
(Accepted August 03 2006)
The first author was supported by a CRM-ISM postdoctoral fellowship. The authors thank T. J. Ransford and T. L. Miller for useful comments and sincere encouragement.