A 3-coloring of Graph Edges so that no two Edges of the same color meet at a Vertex (Ball and Coxeter 1987, pp. 265-266).

**References**

Ball, W. W. R. and Coxeter, H. S. M. *Mathematical Recreations and Essays, 13th ed.* New York: Dover, 1987.

© 1996-9

1999-05-26