The Department of Mathematics and Statistics
Burnside Hall, Room 917
805 Sherbrooke W.
H3A 0B9, Canada
Phone: (514) 398-3805
Fax: (514) 398-3899
I work on category theory, often the kind of category theory that is applicable in theoretical computer science. Earlier, I worked on homological algebra, especially triple cohomology and this ealier work has recently been improved and published in the book Acyclic models. My two other books, both joint with Charles Wells, are Category Theory for Computing Science (newly revised with all material missing from the second edition, including solutions to all the exercises, restored) and Triples, Toposes and Theories, the last one available for free download.
I have also been doing considerable work on understanding and applying Chu categories (and chu categories). More recently, I have been doing joint work with Walter Burgess and Robert Raphael, Robert Raphael and Grant Woods, and now John Kennison and Robert Raphael on epimorphisms of rings of continuous functions induced by subspace inclusions. Recent papers are available by anonymous ftp. Pdf versions of most my papers since the late 1980s are available here.
I am editor (and TeXnical editor) of the electronic journal Theory and Applications of Categories, an editor of the electronic journal Homology, Homotopy and Applications, and an editor of Mathematical Structures in Computer Science.