Definition:Disjoint Union (Set Theory)/Also known as

Disjoint Union: Also known as
A disjoint union in the context of set theory is also called a discriminated union.

In 's original words:
 * We denote the uniting of many aggregates $M, N, P, \ldots$, which have no common elements, into a single aggregate by
 * $\tuple {M, N, P, \ldots}$.
 * The elements in this aggregate are, therefore, the elements of $M$, of $N$, of $P$, $\ldots$, taken together.