recursion

rekursio, toisto The act of recurring.
puhekieltä The act of defining an object (usually a function) in terms of that object itself.
(quote-book)

However, we have still not achieved our goal of devising a finite set of rules which will generate an infinite set of sentence structures. In order to achieve this goal, we need to allow for the fact that natural languages typically have the property that they allow potentially infinite recursion of particular struc- tures. For example, one Clause can be embedded inside another indefinitely many times, ...

n! = n × (n − 1)! (for n > 0) or 1 (for n = 0) defines the factorial function using recursion.

This function uses recursion to compute factorials.