Crossing number may refer to:
- Crossing number (knot theory) of a knot is the minimal number of crossings in any knot diagram for the knot.
- The average crossing number is a variant of crossing number obtained from a three-dimensional embedding of a knot by averaging over all two-dimensional projections.
- Crossing number (graph theory) of a graph is the minimal number of edge intersections in any planar representation of the graph.
Famous quotes containing the words crossing and/or number:
“Bodhidharma sailing the Yangtze on a reed
Lenin in a sealed train through Germany
Hsuan Tsang, crossing the Pamirs
Joseph, Crazy Horse, living the last free
starving high-country winter of their tribes.
Surrender into freedom revolt into slavery—”
—Gary Snyder (b. 1930)
“My tendency to nervousness in my younger days, in view of the fact of a number of near relatives on both my father’s and mother’s side of the house having become insane, gave some serious uneasiness. I made up my mind to overcome it.... In the cross-examination of witnesses before a crowded court-house ... I soon found I could control myself even in the worst of testing cases. Finally, in battle.”
—Rutherford Birchard Hayes (1822–1893)