<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 7-5-4 on page 510.
%% 
%%  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{348.0pt}
\StartShownPreambleCommands
\usepackage[all,arc,knot]{xy}
\StopShownPreambleCommands
\begin{document}
\[
\xy
(0,15)*+{\bullet}="1";
(0,-15)*+{\bullet}="2";
{\ar@{.&gt;} "1";"2"};
"1";"2" **\crv{(10,0)} ?(.97)*\dir{&gt;};
"1";"2" **\crv{(-10,0)} ?(.97)*\dir{&gt;};
"1";"2" **\crv{(25,0)} ?(.97)*\dir{&gt;};
"1";"2" **\crv{(-25,0)} ?(.97)*\dir{&gt;};
(4.5,-5)*+{}="D"; (-4.5,-5)*+{}="C";
(-13,0)*+{}="B"; (12.5,0)*+{}="E";
(0,5)*+{}="A";
{\ar@{=&gt;} "C";"D"};
{\ar@{=&gt;} "B";"C"};
{\ar@{=&gt;} "D";"E"};
{\ar@{:&gt;} "B";"A"};
{\ar@{:&gt;} "A";"E"};
(0,18)*{C \times C \times C \times C};
(0,-18)*{C};
\endxy
\]
\end{document}
</pre></body></html>