Ein Sechsfarbenproblem auf der Kugel

@article{Ringel1965EinSA,
  title={Ein Sechsfarbenproblem auf der Kugel},
  author={Gerhard Von Ringel},
  journal={Abhandlungen aus dem Mathematischen Seminar der Universit{\"a}t Hamburg},
  year={1965},
  volume={29},
  pages={107-117}
}
  • G. Ringel
  • Published 1 December 1965
  • Mathematics
  • Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg
Unter einer Landkarte auf der Kugel verstehen wit eine Zerlegung der Kugel in Fli~chenstiicke (Lgnder), Kanten und Eckpunkte mit den iiblichen Inzidenzeigenschaften. Wir betraehten hier nur Landkarten, bei denen jedes Land topologisehes Bild einer Kreisscheibe ist. Zwei L~nder heiBen benachbart, wenn sie eine gemeinsame Kante (Grenze) haben. Auch zwei Eckpunkte in einer Landkarte oder in einem Graphen, die dureh eine Kante verbunden sind, nermen wir benavhbart. 
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