%%
%% The LaTeX Graphics Companion, 2ed (first printing May 2007)
%%
%% Example 7-4-26 on page 497.
%%
%% 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{159.83385pt}
\StartShownPreambleCommands
\usepackage[all,poly]{xy}
\StopShownPreambleCommands
\begin{document}
\newcounter{node}
%
\[
\renewcommand{\objectstyle}{\scriptstyle}
\newcommand{\Letter}%
{{\setcounter{node}%
{\xypolynode}\Alph{node}}}
%
\begin{xy} /r11mm/:
(2,4.8), {\xypolygon6{~*{\xypolynode}}}
,(2,2.5), {*{0}*\cir<5pt>{}
\xypolygon6{~*{\xybox{%
*{\xypolynode}*\cir<2mm>{}}}}}
,(2,0) , {\xypolygon6{%
~><{@/_.5ex/}
~>>{_{\delta^{\xypolynode}
_{\xypolynum}}}
~<<{@{=}}
~<>{|\uparrow}
~*{\Letter}}}
\end{xy}
\]
\end{document}
