[OS X TeX] Verbatim in displaymath environment

[ewan.Delanoy at math.unicaen.fr]

Hello all,


  I have  some computer science code in my text that I display with
the verbatim environment, and I should like to precede it with
two large vertical bars, usually obtained by \left|\left| in the
displaymath environment. So I tried the following~:

\begin{displaymath}
\left|\left|
 \begin{verbatim}
(...)
\end{verbatim}
\right.\right.
\end{displaymath}

   Not surprisingly, this does not work.
   How would the correct version of this look like?

                                       TIA,

                                           Ewan