texmath-0.10: tests/writers/mfenced-08.tex
\left| \begin{matrix}
U \\
V \\
\end{matrix} \right| = \left\| \begin{matrix}
U \\
V \\
\end{matrix} \right\|
\left| \begin{matrix}
U \\
V \\
\end{matrix} \right| = \left\| \begin{matrix}
U \\
V \\
\end{matrix} \right\|