four color theorem
English
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Four_Colour_Map_Example.svg/220px-Four_Colour_Map_Example.svg.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/World_map_with_four_colours.svg/220px-World_map_with_four_colours.svg.png)
Proper noun
[edit]- (graph theory) A theorem stating that given any separation of a plane into contiguous regions, producing a figure called a map, no more than four colors are required to color the regions so that no two adjacent regions have the same color (adjacent being defined as two regions sharing a boundary, not counting corners, in which three or more regions share a boundary).
Further reading
[edit]Four color theorem on Wikipedia.Wikipedia