<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 7-5-2 on page 509.
%% 
%%  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;/r.22pc/:
(0,2.25)*{}="A";
(0,-2.25)*{}="B";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (-1.33,.5)*{} ; (1.33,.5)*+{}};
(0,8.75)*{}="A";
(0,4.75)*{}="B";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (-1.33,7.5)*{} ; (1.33,7.5)*+{}};
(0,-9.25)*{}="B";
(0,-5.25)*{}="A";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (-1.33,-6.5)*{} ; (1.33,-6.5)*+{}};
(-7,0)*+{\bullet}="1";
(7,0)*+{\bullet}="2";
{\ar@/^.9pc/ "1";"2"};
{\ar@/_.85pc/ "1";"2"};
{\ar@/^2.5pc/ "1";"2"};
{\ar@/_2.5pc/ "1";"2"};
(14,2.25)*{}="A";
(14,-2.25)*{}="B";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (12.67,.5)*{} ; (15.33,.5)*+{}};
(14,8.75)*{}="A";
(14,4.75)*{}="B";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (12.67,7.5)*{} ; (15.33,7.5)*+{}};
(14,-9.25)*{}="B";
(14,-5.25)*{}="A";
{\ar@{=&gt;}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-.46,.35)};
{\ar@{=}@/_.35pc/ "A"+(-1.33,.66) ; "B"+(-1.33,.66)};
{\ar@{=&gt;}@/^.35pc/ "A"+(1.33,.66) ; "B"+(.46,.35)};
{\ar@{=}@/^.35pc/ "A"+(1.33,.66) ; "B"+(1.33,.66)};
{\ar@3{-&gt;} (12.67,-6.5)*{} ; (15.33,-6.5)*+{}};
(7,0)*+{\bullet}="1";
(21,0)*+{\bullet}="2";
{\ar@/^.9pc/ "1";"2"};
{\ar@/_.85pc/ "1";"2"};
{\ar@/^2.5pc/ "1";"2"};
{\ar@/_2.5pc/ "1";"2"};
\endxy
\]
\end{document}
</pre></body></html>