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:
“The methods by which a trade union can alone act, are necessarily destructive; its organization is necessarily tyrannical.”
—Henry George (1839–1897)
“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)
“Our age is pre-eminently the age of sympathy, as the eighteenth century was the age of reason. Our ideal men and women are they, whose sympathies have had the widest culture, whose aims do not end with self, whose philanthropy, though centrifugal, reaches around the globe.”
—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)