[1] viXra:1705.0210 [pdf] replaced on 2017-05-20 07:34:40
Authors: Saenko V.I.
Comments: 3 Pages. This is the Russian version, the English one is directed to the peer-reviewed journal
It is proved that the irreducible map according to Franklin consists of 5 regions and, as a consequence, 4 colors are sufficient for colouring any map on the sphere
Category: Topology