I want to see How to reduce the size of a matrix ?
I have this code:
\begin{center}
\[
\begin{blockarray}{cccccc}
{\{1\}\{2\}\{3\}} & {\{1,2\}\{3\}} & {\{1,3\}\{2\}} & {\{1\}\{2,3\}} & {\{1,2,3\}} \\
\begin{block}{(ccccc)c}
1 & 1 & 1 & 1 & 1 & {\{1\}\{2\}\{3\}} \\
0 & 1 & 0 & 0 & 1 & {\{1,2\}\{3\}} \\
0 & 0 & 1 & 0 & 1 & {\{1,3\}\{2\}} \\
0 & 0 & 0 & 1 & 1 & {\{1\}\{2,3\}} \\
0 & 0 & 0 & 0 & 1 & {\{1,2,3\}} \\
\end{block}
\end{blockarray}
\]
\end{center}

\scaleboxwould allow you to reduce the size to "just small enough". i'd probably try reducing the inter-column spacing a bit first. – barbara beeton Jul 10 '12 at 16:08