Tag Archives: Micha A. Perles

Proof By Lice!

From camels to lice. (A proof promised here.) Theorem (Hopf and Pannwitz, 1934): Let be a set of points in the plane  in general position (no three points on a line) and consider line segments whose endpoints are in .  Then … Continue reading

Posted in Combinatorics, What is Mathematics | Tagged | 5 Comments