More on the Four-Colour Theorem
Another page about the four-colour theorem, this one focusing on a new geometrical proof of the theorem (well, relatively new — the page is dated 1995). Lots of math, no maps. If you recall, the four-colour theorem says that you only need four colours to have a map in which no two adjacent countries have the same colour. See previous entry. Via Plep.
- Buy Four Colors Suffice: How the Map Problem Was Solved at Amazon.com