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 in madness of delusion, anyone shall lift his parricidal hand against this blessed union ... the arms of thousands will be raised to save it, and the curse of millions will fall upon the head which may have plotted its destruction.”
—Andrew Jackson (1767–1845)
“The union of hands and hearts.”
—Jeremy Taylor (1613–1667)
“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)