Union
The union used in set theory is defined in terms of a logical disjunction: x ∈ A ∪ B if and only if (x ∈ A) ∨ (x ∈ B). Because of this, logical disjunction satisfies many of the same identities as set-theoretic union, such as associativity, commutativity, distributivity, and de Morgan's laws.
Read more about this topic: Logical Disjunction
Famous quotes containing the word union:
“In externals we advance with lightening express speed, in modes of thought and sympathy we lumber on in stage-coach fashion.”
—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)
“How can I explain the difference to me between America and Russia?... the America I’ve known is a place where men on horseback escort union marchers, the Russia I’ve known is a place where men on horseback slaughter young Socialists and Jews.”
—Golda Meir (1898–1978)
“Every good cause gained a victory when the Union troops were triumphant. Our final victory was the triumph of religion, of virtue, of knowledge.... During those four years, whatever our motives, whatever our lives, we were fighting on God’s side. We were doing His work. What would this country have been if we had failed?”
—Rutherford Birchard Hayes (1822–1893)