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)
“[Let] the Union of the States be cherished and perpetuated. Let the open enemy to it be regarded as a Pandora with her box opened; and the disguised one, as the Serpent creeping with his deadly wiles into paradise.”
—James Madison (1751–1836)
“If the Union is now dissolved it does not prove that the experiment of popular government is a failure.... But the experiment of uniting free states and slaveholding states in one nation is, perhaps, a failure.... There probably is an “irrepressible conflict” between freedom and slavery. It may as well be admitted, and our new relations may as be formed with that as an admitted fact.”
—Rutherford Birchard Hayes (1822–1893)