Choice Function/Examples/Singletons

Example of Choice Function
Let $\FF$ be a set of singletons.

Then there exists a choice function on $\FF$.

Proof
Let $f: \FF \to \bigcup \FF$ be the mapping defined as:
 * $\forall \set a \in \FF: \map f {\set a} = a$

Then $f$ is trivially a choice function on $\FF$.