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:
“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)
“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)
“... as women become free, economic, social factors, so becomes possible the full social combination of individuals in collective industry. With such freedom, such independence, such wider union, becomes possible also a union between man and woman such as the world has long dreamed of in vain.”
—Charlotte Perkins Gilman (1860–1935)