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 the union of these States, and the liberties of this people, shall be lost, it is but little to any one man of fifty-two years of age, but a great deal to the thirty millions of people who inhabit these United States, and to their posterity in all coming time.”
—Abraham Lincoln (1809–1865)
“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)
“The admission of the States of Wyoming and Idaho to the Union are events full of interest and congratulation, not only to the people of those States now happily endowed with a full participation in our privileges and responsibilities, but to all our people. Another belt of States stretches from the Atlantic to the Pacific.”
—Benjamin Harrison (1833–1901)