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:
“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)