Union and Intersection
If A and B are disjoint sets, then
From this, one can show that in general the cardinalities of unions and intersections are related by
Read more about this topic: Cardinality
Famous quotes containing the words union and/or intersection:
“We must choose. Be a child of the past with all its crudities and imperfections, its failures and defeats, or a child of the future, the future of symmetry and ultimate success.”
—Frances E. Willard 1839–1898, U.S. president of the Women’s Christian Temperance Union 1879-1891, author, activist. The Woman’s Magazine, pp. 137-40 (January 1887)
“If we are a metaphor of the universe, the human couple is the metaphor par excellence, the point of intersection of all forces and the seed of all forms. The couple is time recaptured, the return to the time before time.”
—Octavio Paz (b. 1914)