I used to have an autographed copy of this article -- one of only two autographs I ever received. The other was on a check from Donald Knuth :). Sadly, I seem t

I used to have an autographed copy of this article -- one of only two autographs I ever received. The other was on a check from Donald Knuth :). Sadly, I seem to have lost both of these at some point in the last 15 years :(.