## Kenneth Appel dies, used computer on map question

April 29th, 2013 in Other Sciences / Mathematics**Kenneth Appel, a mathematician who was the first to use a computer to prove a century-old major mathematical theorem, has died at age 80 in Dover, N.H.**

The Tasker Funeral Home confirms that Appel, who was diagnosed with esophageal cancer, died April 19 in hospice care.

Appel was a longtime educator who chaired the University of New Hampshire mathematics department, retiring in 2003.

Before that, he was a faculty member at the University of Illinois at Urbana. In 1976, he and Wolfgang Haken used 1,200 hours of calculations from an IBM computer to prove that a flat map can be colored with just four colors so that contiguous countries have different colors.

Proving the 100-year-old "Four-Color Conjecture" was considered a major intellectual accomplishment.

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"Kenneth Appel dies, used computer on map question." April 29th, 2013. http://phys.org/news/2013-04-kenneth-appel-dies.html