%%
%% The LaTeX Companion, 2ed (second printing August 2004)
%%
%% Example 3-3-20 on page 140.
%%
%% Copyright (C) 2004 Frank Mittelbach, Michel Goossens,
%%    Johannes Braams, David Carlisle, and Chris Rowley
%%
%% 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.
%%

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}

\StartShownPreambleCommands
\usepackage{amsthm}
\theoremstyle{plain}      \newtheorem{thm}{Theorem}
\theoremstyle{definition} \newtheorem{defn}[thm]{Definition}
\theoremstyle{remark}     \newtheorem*{rem}{Remark}
\StopShownPreambleCommands
\begin{document}
\begin{defn}
 A typographical challenge is a problem that cannot be
 solved with the help of \emph{The \LaTeX{} Companion}.
\end{defn}
\begin{thm}There are no typographical challenges.\end{thm}
\begin{rem}The proof is left to the reader.\end{rem}
\end{document}