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 sacred obligation to the Union soldiers must not—will not be forgotten nor neglected.... But those who fought against the Nation cannot and do not look to it for relief.... Confederate soldiers and their descendants are to share with us and our descendants the destiny of America. Whatever, therefore, we their fellow citizens can do to remove burdens from their shoulders and to brighten their lives is surely in the pathway of humanity and patriotism.”
—Rutherford Birchard Hayes (1822–1893)
“You can no more keep a martini in the refrigerator than you can keep a kiss there. The proper union of gin and vermouth is a great and sudden glory; it is one of the happiest marriages on earth, and one of the shortest-lived.”
—Bernard Devoto (1897–1955)
“Some are petitioning the State to dissolve the Union, to disregard the requisitions of the President. Why do they not dissolve it themselves,—the union between themselves and the State,—and refuse to pay their quota into its treasury? Do not they stand in the same relation to the State that the State does to the Union? And have not the same reasons prevented the State from resisting the Union which have prevented them from resisting the State?”
—Henry David Thoreau (1817–1862)