Reducing the vertical line height in an array environment

Question

When I try to use

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{arydshln}
\begin{document}
\[\left[
    \begin{array}{c:c:c}
        \begin{bmatrix}A_l& A_{nl}\end{bmatrix} & B_r & \begin{bmatrix}B_l& B_{nl}\end{bmatrix} \\
        \hdashline
        C &0&0
    \end{array}
    \right]\]
\end{document}

I get:

In this, how can I ensure that the dotted vertical lines stay within the top and bottom bounds defined by the left-right brackets?

Answer 1

A solution with bigstrut to slightly increase the brackets size. Icing on the cake: the horizontal dash line has some vertical padding.

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{bigstrut}
\usepackage{arydshln}

\begin{document}

\[ \left[
    \begin{array}{c:c:c}
        \begin{bmatrix}A_l& A_{nl}\end{bmatrix} & B_r & \begin{bmatrix}B_l& B_{nl}\end{bmatrix} \bigstrut\\
        \hdashline
        C &0&0 \bigstrut[t]
    \end{array}
    \right] \]

\end{document}