%% 
%%  A DANTE-Edition example
%% 
%%  Example 30-02-11 on page 591.
%% 
%%  Copyright (C) 2011 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{153.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks-add,amsmath}

\begin{document}
\[\begin{pmatrix}
  \Rnode[vref=2ex]{A}{~1} \\
    & \ddots \\     && \Rnode[href=2]{B}{1} \\
    &&& \Rnode[vref=2ex]{C}{0} \\
    &&&& \ddots \\  &&&&& \Rnode[href=2]{D}{0}~ \\
\end{pmatrix}\]
\psset{linewidth=0.1pt,rot=-90,nodesep=-0.4}\small
\psbrace(B)(A){n times} \psbrace(D)(C){n times}
\end{document}