What is Five color theorem?
[[File:4CT Non-Counterexample 1.svg|thumb|A map with five colors.]] The '''Five color theorem''' is a [[theorem]] from [[Graph theory]]. It states that any plane which is separated into regions, such as a [[map]], can be colored with no more than five colors. It was first stated by [[Alfred Kempe]] in 1890, and proved by [[Percy John Heawood]] eleven years later. Kempe also tried to prove it, but his proof failed. There are two restrictions which are placed on the maps: First, a country must be contiguous, there must be no [[exclave]]s, and secondly, countries that only touch in one point can be colored with the same color. There is also a [[four color theorem]], which is stronger, and much more difficult to prove. {{math-stub}} [[category:Graph theory]] [[Category:Maps]]