Encyclopedia > Talk:Four color theorem

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Talk:Four color theorem

I removed the following:
It has been proved that maps with countries that cover two or more non-adjacent areas (such as countries with colonies) require a maximum of twelve colours.
Either I don't understand this statement properly, or it is wrong. Suppose country #1 contains colonies of countries #2, #3,...,#n within it. Similarly, country #2 contains colonies of #1, #3,...,#n. And so on. The resulting map will need n colors. AxelBoldt 23:57 Oct 6, 2002 (UTC)

But what happened to the m-pire? This is a legitimate term, see e.g. http://portal.acm.org/citation.cfm?id=355274.355299&coll=Portal&dl=ACM . -phma

I agree - m-pires are an interesting extension (although I also agree that the assertion Axel removed must be wrong).

I will try to make a couple of images here to make the concepts more readily available (picture is worth a thousand words, etc.). In particular, this seems like the kind of topic which mathematically "unsophisticated" types might be very interested in, so we should smooth the intro as much as possible.

Like Fermat's last theorem, the 4-color theorem is rife with amateur "proof" attempts; I know I've seen a summary of common errors somewhere... User:chas_zzz_brown 16:52 7 oct 02 (UTC)

Quick update: from a google search...

Heawood proposed a theorem, but could not prove it. The theorem stated that every m-pire map could be colored with 6m colors (Hartsfield and Ringel). It was not for another 94 years before Jackson and Ringel proved the theorem.

So perhaps the original statement refered to 2-pires... User:chas_zzz_brown 17:34 7 oct 02 (UTC)



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