\begin{definition}[Definition:Nontotient]
A '''nontotient''' is a positive even integer $n$ such that:
:$\nexists m \in \Z_{>0}: \map \phi m = n$
where $\map \phi m$ denotes the Euler $\phi$ function.
That is, a '''nontotient''' is a positive even integer which is not the totient of any positive integer.
\end{definition}