One false proof of this statement was published in 1879 by Alfred Bray Kempe, and an earlycorrespondence about it consists of a letter sent from De Morgan to Hamilton. Francis and FrederickGuthrie originated this problem. Heinrich Heesch's work on this problem led him to originate themethod of discharging. The eventual proof of this statement was simplified by Robertson andSeymour, and was derisively compared to a (*) telephone directory by one critic. That proof was doneby Appel and Hankin using 1200 hours of computer time to check every case. For 10 points, name thisstatement which gives the minimum number of shades needed to color a map. 
One false proof of this statement was published in 1879 by Alfred Bray Kempe, and an earlycorrespondence about it consists of a letter sent from De Morgan to Hamilton. Francis and FrederickGuthrie originated this problem. Heinrich Heesch's work on this problem led him to originate themethod of discharging. The eventual proof of this statement was simplified by Robertson andSeymour, and was derisively compared to a (*) telephone directory by one critic. That proof was doneby Appel and Hankin using 1200 hours of computer time to check every case. For 10 points, name thisstatement which gives the minimum number of shades needed to color a map. 
One false proof of this statement was published in 1879 by Alfred Bray Kempe, and an earlycorrespondence about it consists of a letter sent from De Morgan to Hamilton.
four color theorem