%%
%% The LaTeX Graphics Companion, 2ed (first printing May 2007)
%%
%% Example 8-2-53 on page 547.
%%
%% Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss
%%
%% 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{207.83385pt}
\StartShownPreambleCommands
\usepackage[pictex]{m-ch-en}
\StopShownPreambleCommands
\begin{document}
\[ \chemical{2H_2}{}
\chemical{PLUS}{}
\chemical{O_2}{}
\chemical{GIVES}{}
\chemical{2H_2O}{} \]
\end{document}