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:
“If the union of these States, and the liberties of this people, shall be lost, it is but little to any one man of fifty-two years of age, but a great deal to the thirty millions of people who inhabit these United States, and to their posterity in all coming time.”
—Abraham Lincoln (1809–1865)
“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)
“And thus they sang their mysterious duo, sang of their nameless hope, their death-in-love, their union unending, lost forever in the embrace of night’s magic kingdom. O sweet night, everlasting night of love! Land of blessedness whose frontiers are infinite!”
—Thomas Mann (1875–1955)