Walter TholenWalter Tholen is a Professor of Mathematics at York University, Toronto and an internationally recognized specialist of category theory and its applications to algebra, topology and computer science. His work encompasses some 120 published papers on arious subjects, ranging from the fundamental study of categories (in particular, of monads, factorization systems and closure operators) to their applications (in particular, in general topology, homotopy theory, duality theory). Twelve students wrote their PhD theses under his supervision. He has co-authored several books and serves on various editorial boards. He is also an engaged academic administrator, currently serving as Associate Vice-President Research of the university. Read More Read Less