Dear Steve, Thank you for your kind words. I have mentioned my paper with Aurelio only because there are too many details that I could not describe in a brief email message. But if it comes to "...I should have mentioned explicitly your work with Aurelio...", I can say the same about myself: I should have mentioned your (very important!) paper [A. Carboni, S. Lack, and R. F. C. Walters, Introduction to extensive and distributive categories, Journal of Pure and Applied Algebra 84, 1993, 145-158] and Bill Lawvere's original question about commutative rings and many other things that Aurelio did mention in his CT1999 talk. (In any case, I hope you do not assume that I know what "Coq" is, do you?) Yours- George ----- Original Message ----- From: "Stephen Lack" <S.Lack@uws.edu.au> To: "George Janelidze" <janelg@telkomsa.net>; <categories@mta.ca> Cc: "Andrej Bauer" <Andrej.Bauer@fmf.uni-lj.si> Sent: Friday, October 27, 2006 9:51 AM Subject: RE: categories: RE: Characterization of integers as a commutative ring with unit Dear George, I remember well your lovely talk and paper, and indeed I had this in mind when I wrote. I shouldn't have used the words "extra structure" (in fact I said this really because I don't know what "Coq" is) and I should have mentioned explicitly your work with Aurelio. Sorry. Steve.