In mathematics, the four color theorem, or the four color map theorem, states 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 of the map so that no two adjacent regions have the same color.
Petega člana družine "Physical Review E" so začeli objavljati leta 1993 in ga prilagodili veliki količini novih raziskav v nelinearni dinamiki.