Date: Mar 5, 2014 3:38 PM
Subject: Re: 4 colors problem
>So far there has not been a single point raised for any errors
>or omissions or faulty or incomplete logic in the way this
>conclusion was reached.
I haven't followed the thread in full, but my sense is that
you misunderstand the claim of the 4-color theorem.
The 4-color theorem does _not_ guarantee that any partial
4-coloring of a planar graph can be extended to a 4-coloring
of the full graph.
Rather, it asserts that for a planar graph there exists at
least one valid coloring using at most 4 colors.
Thus, to find a counterexample to the 4-color theorem, you
would have to produce a planar graph such that _all_ valid
coverings (not just one of your choosing) use more than
However, the very fact that the 4-color theorem is actually
a theorem (the logic of the proof has been extensively
analyzed and verified) guarantees that any attempt to produce
such a counterexample will fail.