# Problem with \bordermatrix inside array

When a \bordermatrix is placed inside an array, the spacing between rows will be wrong (see the MWE below). What is causing this problem? Is there a solution?

\documentclass{book}

\begin{document}

A simple matrix created with \verb+\bordermatrix+; right spacing between rows:
$\bordermatrix{% & 1 & 2 \cr 1 & x1 & x2 \cr 2 & x3 & x4 \cr 3 & x5 & x6}$

The same matrix inside an \texttt{array}; wrong spacing between rows:
$\begin{array}{c} \bordermatrix{% & 1 & 2 \cr 1 & x1 & x2 \cr 2 & x3 & x4 \cr 3 & x5 & x6} \end{array}$

\end{document}

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This is caused because the \bordermatrix uses the \baselineskip for the spacing and array sets this to 0pt.

Restoring the value of \baselineskip in the cell fixes the issue:

\documentclass{book}

\begin{document}

$\edef\savedbaselineskip{\the\baselineskip\relax} \begin{array}{c} {\baselineskip=\savedbaselineskip \bordermatrix{% & 1 & 2 \cr 1 & x1 & x2 \cr 2 & x3 & x4 \cr 3 & x5 & x6}} \end{array}$

\end{document}


This is done inside a group to keep the definition local.

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An altenative way to restoring \baselineskip, which has been shown by Martin, is using \parbox or minipage for embedding the \bordermatrix, within the array. This would also restore the spacing.

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