In mathematics, the term disjoint union may refer to one of two different but related concepts:
- In set theory, the disjoint union (or discriminated union) of a family of sets is a modified union operation that indexes the elements according to which set they originated in; disjoint sets have no element in common.
- When one says that a set is the disjoint union of a family of subsets, this means that it is the union of the subsets and that the subsets are pairwise disjoint.
Read more about Disjoint Union: Set Theory Definition, Category Theory Point of View
Famous quotes containing the word union:
“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)