I keep reading that Kempe has proven that every vertex in a 5-chroma planar graph must have degree >= 5, but nowhere can I find this proof.

Could someone please explain the proof or point me in the right direction?

Many thanks in advance,

Katie

- Apr 19th 2012, 12:32 PMktharmerEvery vertex in a 5-chroma planar graph must have degree >=5. WHY?!
I keep reading that Kempe has proven that every vertex in a 5-chroma planar graph must have degree >= 5, but nowhere can I find this proof.

Could someone please explain the proof or point me in the right direction?

Many thanks in advance,

Katie