Mike Kallaher,
Department of Mathematics,
Washington State University,
Pullman, WA 99164-3113,
Clare Wiser ,
Department of Mathematics,
Washington State University,
Pullman, WA 99164-3113,
503-768-7559 (office), 503-332-2498 (home), fax: 509-335-1188
Last updated 14 June 1996