I was reading the 1st thread in the ruby-math discussion at http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-math/ (it in Japanese, but Excite has an auto translater--its interesting to see how it translates Japanese to English). If anyone cares, what I got was basically this. If + is commutative, and the successor operation to + is *, which is also commutative; (a*b = b*a), then why isn't a**b = b**a since ** is successor operation to * ? Some discussion of induction and Peano axioms, which I didn't think through. Van