texmath-0.6.7: tests/writers/mfenced-08.tex
\left|\begin{array}{c}
{U} \\
{V} \\
\end{array}\right|=\left\| \begin{array}{c}
{U} \\
{V} \\
\end{array}\right\| \left|\begin{array}{c}
{U} \\
{V} \\
\end{array}\right|=\left\| \begin{array}{c}
{U} \\
{V} \\
\end{array}\right\|