A function
from which is defined the iteration
for any element
x in set
X. Thus a new function
is created by
where
N is the set of natural numbers. The construct that makes
F from
f is, under certain circumstances, equivalent with the construct of primitive recursion. Iterated maps are used to model the dynamical behaviour of computers (for example, by iterating a next state function) and physical systems (for example, a neurone firing), and to generate fractals.