\begin{center}\begin{minipage}{15cm}\begin{Verbatim}[frame=single]
> succ = proc(n) { return n + 1; };
> succ(5);
6
> 3 + succ(0);
4
> succ;
proc(n)
{
nop;
return (n) + (1);
}
\end{Verbatim}
\end{minipage}\end{center}
