BERNARD R. GELBAUM is Professor of Mathematics at the State University of New York at Buffalo. He has previously served on the faculties of the University of Minnesota, the University of California, Irvine, and as a Fulbright Senior Scholar at University College, Galway, Ireland. He has published research in analysis and probability theory and is the author of Theorems and Counterexamples in Mathematics; Problems in Real and Complex Analysis; and Linear Algebra: Basics, Practice and Theory.