I meant such that the "countries" are volumes not surfaces - and I suspect the answer is 5 (based on change from triangle to tetrahedron). On 29 Apr 2013, at 22:52, meekerdb wrote:
In 3D you can add "handles" connecting any two countries; so it can take one color per country.
Brent
On 4/29/2013 6:59 AM, Dave Makin wrote:
I assume these "countries" didn't include any "holey" ones i.e. rings etc. ?
Also given the equivalent assumptions is the answer for 3D just 5 colours ?
On 29 Apr 2013, at 13:48, Henry Baker wrote:
FYI -- How is it possible that I never knew that (computer scientist) Andrew Appel was Kenneth Appel's son? Obviously, Appel's don't fall far from the tree...
http://www.nytimes.com/2013/04/29/technology/kenneth-i-appel-mathematician-w...
Kenneth I. Appel, Mathematician Who Harnessed Computer Power, Dies at 80
By DENNIS OVERBYE
Published: April 28, 2013
Kenneth I. Appel, who helped usher the venerable mathematical proof into the computer age, solving a longstanding problem concerning colors on a map with the help of an I.B.M. computer making billions of decisions, died on April 19 in Dover, N.H. He was 80. <snip>
The meaning and purpose of life is to give life purpose and meaning. The instigation of violence indicates a lack of spirituality.
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
The meaning and purpose of life is to give life purpose and meaning. The instigation of violence indicates a lack of spirituality.