Thane Plambeck <tplambeck@gmail.com> wrote:
Another triumph in mathematical journalism http://www.bbc.co.uk/berkshire/content/articles/2006/12/06/divide_zero_featu...
Apparently James Anderson thinks that he has discovered something new by developing a consistent system of arithmetic for reals extended by infinity and undefined (which he calls nullity). Of course any competent calculus student is aware of such laws. They've been implemented in computer algebra systems for decades. See his papers below for details (which include links to machine-checked proofs in Isabelle/HOL). http://www.bookofparagon.com/Mathematics/PerspexMachineVIII.pdf http://www.bookofparagon.com/Mathematics/PerspexMachineIX.pdf http://www.bookofparagon.com/News/News_00012.htm --Bill Dubuque