Let E; F be 2 points in the plane, EF has length 1,
and let N be a continuous curve from E to F. A chord of N is a
straight line joining 2 points on N. Prove if 0 < E; F < 1,
and N has no chords of length E or F parallel to EF, then N has no
chord of length E + F parallel to EF. Prove that N has chords of
length 1/X parallel to EF for all positive integers X.