h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Strange, you say "His elegant proof, as with any proof of this theorem, is too long and complicated to describe in full in this Entry..." and then go on to pretty much describe it in full. A tiny bit more about Kempe chains would make everything clear...

Hi Bob

Yes, you're quite right that I went much of the way to describe Kempe's 'proof'.

I decided that to include Kempe chains would have unbalanced the article a bit. It would have taken another long section with some relatively complex diagrams, and then I'd have needed to explain Heawood's discovery in more detail, too, and that would take some very complex diagrams indeed.

I felt it would have put off the non-mathematician, and Kempe's turned out to be a flawed proof in any case. Maybe I'll try to link to a good online resource which can take people further if they need. (any suggestions?)

Icy