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)
“The two great points of difference between a democracy and a republic are: first, the delegation of the government, in the latter, to a small number of citizens elected by the rest; secondly, the greater number of citizens and greater sphere of country over which the latter may be extended.”
—James Madison (1751–1836)