%% The LaTeX Graphics Companion, 2ed (first printing May 2007)

%%
%% The LaTeX Graphics Companion, 2ed (first printing May 2007)
%%
%% Example 7-4-38 on page 505.
%%
%% 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{183.83385pt}
\StartShownPreambleCommands
\usepackage[all,poly,knot,dvips]{xy}
\StopShownPreambleCommands
\begin{document}
\[\UseTips
\renewcommand{\labelstyle}{\scriptscriptstyle}
\begin{xy} /r9mm/:
,(0,0)
,{\hunder<><{1}|>|{2}>>>{3}%
\htwist<<<{4}|>|{5}><>{6}%
\hloop<><{7}|>|{8}>>>{9}}
,(0,-3)
,{\hunder<(+0.1)><{1}|>|{2}>>>{3}%
\htwist<<<{4}|(-.2)>|(-.2){^{5}}><>{6}%
\hloop<(+.1)><{7}|>|{8}>>>(-.1){9}}
\end{xy}\]
\end{document}