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)
“Maybe we were the blind mechanics of disaster, but you don’t pin the guilt on the scientists that easily. You might as well pin it on M motherhood.... Every man who ever worked on this thing told you what would happen. The scientists signed petition after petition, but nobody listened. There was a choice. It was build the bombs and use them, or risk that the United States and the Soviet Union and the rest of us would find some way to go on living.”
—John Paxton (1911–1985)
“To emancipate [the slaves] entirely throughout the Union cannot, I conceive, be thought of, consistently with the safety of the country.”
—Frances Trollope (1780–1863)