Given an arrangement of points, a Line containing just two of them is called an ordinary line. Moser (1958) proved that at least lines must be ordinary (Guy 1989, p. 903).

**References**

Guy, R. K. ``Unsolved Problems Come of Age.'' *Amer. Math. Monthly* **96**, 903-909, 1989.

© 1996-9

1999-05-26