\documentclass[a4paper]{article}
% \usepackage{times}
\usepackage{easybmat}%

\let\package\texttt % so \package{foo} comes out in \tt
\let\envname\textsf % so \envname{foo} comes out as \sf

\newbox\tempbox

\def\BOX{%
    \setbox\tempbox\hbox\bgroup
    \begin{minipage}{0.9\textwidth}
}
\def\endBOX{%
    \end{minipage}
    \egroup
    \par\bigskip
    \begin{center}
        \fboxsep=10pt\fbox{\box\tempbox}
    \end{center}
    \bigskip\par
}

\title{The package \package{easybmat}}
\author{Enrico Bertolazzi\\\\
  Laboratorio di Matematica Applicata\\
  Dipartimento di Ingegneria Civile ed Ambientale\\
  Universit\`a degli Studi di Trento\\
  Mesiano, Trento, Italy\\\\
  \texttt{bertolaz@ing.unitn.it}}

\date{}

\begin{document}
\maketitle
\begin{abstract}
The \package{easybmat} package is 
a macro package for writing block matrices, with equal column widths 
or equal rows heights or both, with various
kinds of rules~(lines) between rows and columns. It
uses an array/tabular-like syntax. 
\end{abstract}

\tableofcontents

\section{Some examples with \package{easybmat}}
Load the package in the usual way:
\begin{BOX}
\begin{verbatim}
   \documentclass{article}
   .
   .
   \usepackage[thinlines,thiklines]{easybmat}
   .
   .
\end{verbatim}
\end{BOX}
The options \texttt{thinlines}, and \texttt{thiklines} are self explanatory.
\package{easybmat} provides the \envname{BMAT}~environment which is a
simple re-implementation of the
array/tabular environment, with some limitation and some additional features.
The syntax is
\begin{BOX}
\begin{verbatim}
   \begin{BMAT}`(x)'`[2pt]'`{cc...c}'`{cc...c}'
      a & b & ... & n \\
   .
   \end{BMAT}
\end{verbatim}
\end{BOX}
\begin{description}
\item[(x)] is an optional parameter, if present it specify if you want to 
balance the rows or the column or both, as this table shows:
\begin{center}
\begin{tabular}{|l|l|}
\hline
value of $x$ & effect \\
\hline
\verb+r+ & equal rows heights \\
\verb+c+ & equal column widths  \\
\verb+b+ & equal rows heights and equal column widths \\
\verb+e+ & equal rows heights and column widths \\
\hline
\end{tabular}
\end{center}

\item[]\verb+[2pt]+ an optional parameter that specify
the amount of extra space around the item 
in the \envname{BMAT} environment. The default is \verb+2pt+.
\item[the first] \verb+`{cc...c}'+ is the definition of the columns
and their alignment. The possible alignment for
the columns are:
\begin{center}
\begin{tabular}{|l|l|}
\hline
\verb+c+ & centering \\
\verb+l+ & flush left \\
\verb+r+ & flush right \\
\hline
\end{tabular}
\end{center}
\item[the second] \verb+`{cc...c}'+ is the
definition of the rows their alignment.
The possible alignment for
the rows are:
\begin{center}
\begin{tabular}{|l|l|}
\hline
\verb+c+ & centering \\
\verb+t+ & flush top \\
\verb+b+ & flush bottom \\
\hline
\end{tabular}
\end{center}
\end{description}
It is possible to produce rules between columns or rows as this 
example shows:
\begin{BOX}
\begin{verbatim}
\[ \begin{BMAT}(b){|l:cr|}{|t;cb|}
     1 & 1 & 1 \\
     1 & \frac{111}{222} & 1 \\
     1 & 1 & 1 
   \end{BMAT}
   \qquad
   \begin{BMAT}(b){|r:cl|}{|b;ct|}
     1 & 1 & 1 \\
     1 & \frac{111}{222} & 1 \\
     1 & 1 & 1 
   \end{BMAT}
\]
\end{verbatim}
\end{BOX}
which produce the following output:
\begin{BOX}
\[ \begin{BMAT}(b){|l:cr|}{|t;cb|}
     1 & 1 & 1 \\
     1 & \frac{111}{222} & 1 \\
     1 & 1 & 1 
   \end{BMAT}
   \qquad
   \begin{BMAT}(b){|r:cl|}{|b;ct|}
     1 & 1 & 1 \\
     1 & \frac{111}{222} & 1 \\
     1 & 1 & 1 
   \end{BMAT}
\]
\end{BOX}
The available rules for the rows and columns are
\begin{center}
\begin{tabular}{|l|l|}
\hline
nothing  & no rule \\
\verb+|+ & solid line \\
\verb+:+ & dash line \\
\verb+;+ & dot-dash line \\
\verb+.+ & dotted line \\
\verb+0+ & solid line with size $1/5$ of normal line \\
\verb+1+ & solid line with size $1/4$ of normal line \\
\verb+2+ & solid line with size $1/3$ of normal line \\
\verb+3+ & solid line with size $1/2$ of normal line \\
\verb+4+ & equivalent to \verb+|+ \\
\verb+5+ & solid line with size $2$ times of normal line \\
\verb+6+ & solid line with size $3$ times of normal line \\
\verb+7+ & solid line with size $4$ times of normal line \\
\verb+8+ & solid line with size $5$ times of normal line \\
\verb+9+ & solid line with size $6$ times of normal line \\
\hline
\end{tabular}
\end{center}
The main feature of the \envname{BMAT}~environment
is that it is reentrant:
\begin{BOX}
\begin{verbatim}
\[ \begin{BMAT}{0c.c9}{|c.c|}
     1 & 2 \\
     3 & \begin{BMAT}{c:c}{c:c}
              a & b \\
              c & d
         \end{BMAT}
   \end{BMAT}
\]
\end{verbatim}
\end{BOX}
which produces
\begin{BOX}
\[ \begin{BMAT}{0c.c9}{|c.c|}
     1 & 2 \\
     3 & \begin{BMAT}{c:c}{c:c}
              a & b \\
              c & d
         \end{BMAT}
   \end{BMAT}
\]
\end{BOX}

\section{Some example with balancing}
Here it is showed the effect of various balancing
\begin{BOX}
\begin{verbatim}
\[
   \begin{BMAT}{|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(r){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(c){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
\]
\[
   \begin{BMAT}(b){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(e){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
\]
\end{verbatim}
\end{BOX}
which produce:
\begin{BOX}
\[
   \begin{BMAT}{|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(r){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(c){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
\]
\[
   \begin{BMAT}(b){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
   \quad
   \begin{BMAT}(e){|c|c|c|}{|c|c|c|}
       1 & 22 & 333 \\
       \frac{1}{2} & 1 & 1 \\
       \frac{1}{\frac{1}{2}} & 1 & 1
   \end{BMAT}
\]
\end{BOX}

\section{An example with size}
This example shows the use of various size rule in \envname{BMAT} 
environment:
\begin{BOX}
\begin{verbatim}
\[ \begin{BMAT}(e)[5pt]{0c1c2c3c4c5c6c7c8c9}
                       {0c1c2c3c4c5c6c7c8c9}
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & *
   \end{BMAT}
\]
\end{verbatim}
\end{BOX}
which produce
\begin{BOX}
\[ \begin{BMAT}(e)[5pt]{0c1c2c3c4c5c6c7c8c9}
                       {0c1c2c3c4c5c6c7c8c9}
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & * \\
   * & * & * & * & * & * & * & * & *
   \end{BMAT}
\]
\end{BOX}

\section{An example with reentrance}
This final example shows a slightly more complex (reentrant)
definition in 
which the \envname{BMAT}~environment is used:
\begin{BOX}
\begin{verbatim}
\def\rec(#1){\expandafter\recurse#1-\end}
\def\recurse#1#2\end{%
 \if\noexpand#1-\def\next##1##2{}%
 \else\let\next=\recursea\fi%
 \expandafter\next{#1}{#2}%
}%
\def\recursea#1#2{%
  \bgroup
    \begin{BMAT}{|l:c:r|}{.t;c;b.}
       \rec(#2) &      #1  & \rec(#2) \\
             #1 & \rec(#2) & #1       \\
       \rec(#2) &      #1  & \rec(#2)
    \end{BMAT}
  \egroup
}
\[ \recurse\clubsuit\diamondsuit\heartsuit\end \]
\end{verbatim}
\end{BOX}
It produces the following output:
\typeout{This example can take a while to compile on small machine, please wait...}
\def\rec(#1){\expandafter\recurse#1-\end}
\def\recurse#1#2\end{%
 \if\noexpand#1-\def\next##1##2{}%
 \else\let\next=\recursea\fi%
 \expandafter\next{#1}{#2}%
}%
\def\recursea#1#2{%
  \bgroup
    \begin{BMAT}[0pt]{l:c:r}{t;c;b}
       \rec(#2) &      #1  & \rec(#2) \\
             #1 & \rec(#2) & #1       \\
       \rec(#2) &      #1  & \rec(#2)
    \end{BMAT}
  \egroup
}\small
\[ \recurse\clubsuit\diamondsuit\heartsuit\end \]
\typeout{...thanks, I have done}

\end{document}