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:
“Every good cause gained a victory when the Union troops were triumphant. Our final victory was the triumph of religion, of virtue, of knowledge.... During those four years, whatever our motives, whatever our lives, we were fighting on God’s side. We were doing His work. What would this country have been if we had failed?”
—Rutherford Birchard Hayes (1822–1893)
“What should concern Massachusetts is not the Nebraska Bill, nor the Fugitive Slave Bill, but her own slaveholding and servility. Let the State dissolve her union with the slaveholder.... Let each inhabitant of the State dissolve his union with her, as long as she delays to do her duty.”
—Henry David Thoreau (1817–1862)
“We are constantly thinking of the great war ... which saved the Union ... but it was a war that did a great deal more than that. It created in this country what had never existed before—a national consciousness. It was not the salvation of the Union, it was the rebirth of the Union.”
—Woodrow Wilson (1856–1924)