# using multiple brace in array environment

I want to create something like that

Clearly every element should be coherent with eachother and line need to be connected. This is a MWE, how should I modify it to make it coherent:

\documentclass{beamer}
\mode<presentation>

\usetheme{Warsaw}
\usepackage[utf8]{inputenc}

\begin{document}
\begin{frame}
$\begin{array}{c|c} x_i & lat_i \\ \hline \end{array}$
$\left.\begin{array}{c|c} t_1 & lat_1 \\ \hline t_2 & lat_2 \\ \end{array} \right\rbrace = a$$\left.\begin{array}{c|c} t_3 & lat_3 \\ \hline t_4 & lat_4 \\ \end{array} \right\rbrace = b$
\end{frame}
\end{document}

-
– Ignasi May 8 '12 at 10:53

## 1 Answer

I'm not sure if I fully understand what you mean by "the lines need to be connected" -- should they be connected vertically, or should the first line extend horizontally?

If you want to join the vertical lines (but not extend the first horizontal line to the right), you may want to use the capabilities of the multirow package:

\documentclass{beamer}
\mode<presentation>
\usetheme{Warsaw}
\usepackage[utf8]{inputenc}
\usepackage{multirow}  % for \multirow command
\begin{document}
\begin{frame}
$\begin{array}{c|cl} x_i & lat_i \\ \cline{1-2} t_1 & lat_1 & \multirow{2}*{\bigg\} = a}\\ \cline{1-2} t_2 & lat_2 & \\ t_3 & lat_3 & \multirow{2}*{\bigg\} = b}\\ \cline{1-2} t_4 & lat_4 & \\ \end{array}$
\end{frame}
\end{document}


Incidentally, if you want to have the first horizontal line to extend over the entire width of the array, you can do so by replacing the first \cline{1-2} instruction with \hline.

Alternatively, you could use the following MWE if you wish to extend the first horizontal line so that it spans all subsequent material (while lining up the vertical lines). The second MWE also reduces (but does not fully eliminate) the vertical gap between the arrays, by using the gather* environment.

\documentclass{beamer}
\mode<presentation>
\usetheme{Warsaw}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}  % for gather (and gather*) math environment
\begin{document}
\begin{frame}
\begin{gather*}
\begin{array}{c|c}
x_i & lat_i \hphantom{\Bigg\}=a}\\
\hline
\end{array}\\
\left.\begin{array}{c|c}
t_1 & lat_1 \\
\hline
t_2 & lat_2 \\
\end{array}
\right\rbrace = a\\
\left.\begin{array}{c|c}
t_3 & lat_3 \\
\hline
t_4 & lat_4 \\
\end{array}
\right\rbrace = b
\end{gather*}
\end{frame}
\end{document}


-
Last image is exactly what I need. If you want you could change first attempt ;) – Mariano May 8 '12 at 14:10
@Mariano -- Glad I guessed right with the MWE that uses multirow. I'll leave both MWEs in place but will reverse the order per your suggestion. – Mico May 8 '12 at 14:18