Rudolf Fritsch (Ludwig-Maximilians-Universität München)
The 150th Birthday of the Four Colour Problem - Theorem

The first written document treating the Four Colour Theorem is a letter from Augustus de Morgan to Sir William Rowan Hamilton, dated on October 23, 1852. More than 120 years of interesting mathematical research were needed for the first solution by Kenneth Appel, Wolfgang Haken and John Koch. The aim of the lecture is to present some special points of the history of the problem and to give an idea how the computer aided proof works. The strange point is that the truth of the theorem is still dependent on the reliability of the involved computer programs.