Hadwiger–Nelson problem on the chromatic number of unit distance graphs in the Euclidean plane
Nelson Mandela | Willie Nelson | Nelson | Horatio Nelson, 1st Viscount Nelson | Nelson, New Zealand | Ricky Nelson | Nelson Rockefeller | Horatio Nelson | Lord Nelson | Nelson Riddle | Bill Nelson | Marc Nelson | Oliver Nelson | Nelson-Atkins Museum of Art | Nelson A. Miles | Nelson Eddy | Nelson Bunker Hunt | Craig T. Nelson | Byron Nelson | Ted Nelson | William Nelson Cromwell | Nelson Piquet | Nelson County, Kentucky | Tim Blake Nelson | Nelson's Column | Nelson, Lancashire | Nelson Chai | Nelson, British Columbia | Judd Nelson | John Nelson Darby |
Hadwiger's theorem characterizing measure functions in Euclidean spaces