The concept of ordered -tuplet is the generalization of ordered pair to items. For small values of , the following terms are used:

This notion can be defined set-theoretically in a number of ways. For convenience, we shall express two of these definitions for quintuplets -- it is perfectly easy to generalize them to any other value of .

One possibility is to build -tuplets out of nested ordered pairs. In the case of our example , the representation as a nested ordered pair looks like

Another possibility is to define -tuplets as maps. In this way of thinking, a quintuplet is a function whose domain is the set . In the case of our example, the function in question is defined as

Especially with the second interpretation, one sees that a synonym for "ordered tuplet" is "finite sequence" or "list". For instance, a quintuplet can also be regarded as a sequence of five items or a list of five items.