\item \self In the following list, tick all items that are required for a
    complete model of a formula $\varphi$ in predicate logic.
\begin{itemize}
\item[$\square$] A non-empty, possibly infinite set of values for
    variables and functions.
\item[$\square$] A concrete value for every bound variable in
    $\varphi$.
\item[$\square$] A concrete value for free bound variable in
    $\varphi$.
\item[$\square$] A definition for each predicate in $\varphi$,
    detailing for which values/tuples the predicate returns
    \emph{true}.
\item[$\square$] A definition for each function in $\varphi$,
    detailing for which values/tuples the predicate returns
    \emph{true}.
\end{itemize}