% pb-examples.tex: nifty example using pb-diagram.sty
% Authors: Bill Richter et al.
% Version Number: 4.1
% Version Date: 24 Jan 1997
%
\def\tooee{LaTeX2e}
\ifx\fmtname\tooee
   \documentclass[12pt]{article}\usepackage{pb-diagram}
\else
   \documentstyle[12pt,pb-diagram]{article}
\fi
\title{Examples of the Diagram Environment}
\author{Stolen from Various Sources}
\begin{document}
\maketitle

\setlength{\fboxsep}{0pt}

This ridiculous example shows how the package fits
arrows in between the formulas, taking into  account the
exact size of every formula.  (The box around the diagram
shows how  the shape of the entire diagram is made known to
\LaTeX.)   Note that diagonal  arrows are fitted to either
the tops or sides of the formulas, depending  individual
circumstances.
\begin{center}\fbox{$
\begin{diagram}
\node{\left[\begin{array}{cc} A_{00} & A_{01} \\
      A_{10} & A_{11}\end{array}\right]}
      \arrow{e,t}{a} \arrow{s,l}{c} \arrow{ese,b,1}{u}
   \node{B^*} \arrow{e,t}{b^*}
      \node{C} \arrow{s,r}{d} \arrow{wsw,b,1}{v}
\\
\node{D} \arrow[2]{e,b}{e}
   \node[2]{H^2(X,\, \omega_X \otimes L^{\otimes(-n^2+n)})}
\end{diagram}
$}\end{center}

% Catcode hack to get typewriter `\' inside arg of another command
% where \verb is illegal.
\begingroup \catcode`|=0 \catcode`\\=12
   |gdef|bbb{{|tt\}}%
|endgroup
%
\makeatletter
\@ifundefined{lamsvector}{%
   (There are some additional diagrams at this point in the file,
   which you can see if you add
   \ifx\fmtname\tooee
      {\tt\bbb usepackage\{lamsarrow\}\bbb usepackage\{pb-lams\}}
      at the end of the list of included packages.) 
   \else
      \mbox{\tt lamsarrow,pb-lams} at the end of the
      document style options.)
   \fi
}{%
\newpage
This diagram shows off the fancy arrows fonts from LamS-\TeX.
\[
\begin{diagram}
\node{A} \arrow{e,t,V}{a} \arrow{s,l,'}{c} \arrow{ese,b,1,`}{u}
   \node{B} \arrow{e,t,A}{b}
      \node{C} \arrow{s,r,J}{d} \arrow{wsw,b,1,L}{v} \\
\node{D} \arrow[2]{e,b,S}{e}
   \node[2]{E}
\end{diagram}
\]

The two diagrams below differ only in that the second has an extra diagonal 
arrow.  Because the first diagram is naturally very long, this diagonal arrow 
could not be drawn into the first diagram even with the LamS-\TeX\ fonts.  So 
the diagram automatically compromises the diagram's aspect ratio to make the 
arrow possible.
\[
\begin{diagram}
\node{\rule{80pt}{1pt}} \arrow[3]{e} % remove arrow: \arrow{seee,..}
   \node[3]{\rule{80pt}{1pt}} \arrow{s}\\
\node{\rule{80pt}{1pt}} \arrow{e}
   \node{\rule{80pt}{1pt}} \arrow{e}
      \node{\rule{80pt}{1pt}} \arrow{e}
         \node{\rule{80pt}{1pt}}
\end{diagram}
\]
\[
\begin{diagram}
\node{\rule{80pt}{1pt}} \arrow[3]{e} \arrow{seee,..}
   \node[3]{\rule{80pt}{1pt}} \arrow{s}\\
\node{\rule{80pt}{1pt}} \arrow{e}
   \node{\rule{80pt}{1pt}} \arrow{e}
      \node{\rule{80pt}{1pt}} \arrow{e}
         \node{\rule{80pt}{1pt}}
\end{diagram}
\]}
\makeatother

\newpage
These examples show how to simulate split arrows by placing the diagram on a finer grid than logically necessary.
\[
   \dgARROWLENGTH=0.6\dgARROWLENGTH
   \begin{diagram}
                           \node[2]{A}\arrow[2]{s}\\
      \node{B}\arrow{e,-}  \node{}\arrow{e,t}{\alpha}      \node{C} \\
                           \node[2]{D}\arrow{ne,b}{\beta}
   \end{diagram}
\]

\[
\begin{diagram}
\node{A} \arrow[2]{e,t}{a} \arrow[2]{s,l}{c} \arrow[2]{ese,t,3}{u}
   \node[2]{B^*} \arrow[2]{e,t}{b^*}
      \node[2]{C} \arrow[2]{s,r}{d} \arrow{wsw,-} 
\\
        \node[3]{} \arrow{wsw,t}{v}
\\
\node{D} \arrow[4]{e,b}{e}
   \node[4]{E}
\end{diagram}
\]


\newpage
Here are several ``real life'' examples from Bill Richter's work:
%%%% Note: for ease of tex-ing we don't assume extra fonts.
\let\frak\relax
\let\Bbb=\relax
%%%%
%\font\tenfrak=eufm10 scaled \magstep1
%\font\sevenfrak=eufm7 scaled \magstep1
%\font\fivefrak=eufm5 scaled \magstep1
%\newfam\frakfam \def\frak{\fam\frakfam\tenfrak} \textfont\frakfam=\tenfrak
%\scriptfont\frakfam=\sevenfrak  \scriptscriptfont\frakfam=\fivefrak
%%%%
%%%%
\def\a{ \alpha }
\def\d{ \delta }
\def\s{ \sigma }
\def\l{ \lambda }
\def\p{ \partial }
\def\st{{\tilde\s}}
\def\O{ \Omega }
\def\S{\Sigma}
\def\Z{{\Bbb Z }}
\def\@{ \otimes }
\def\^{ \wedge }
\def\({ \left( }
\def\){ \right) }
\def\K#1{{ K\(\Z/2,#1\) }}
\def\KZ#1{{K\(\Z/4,#1\) }}
\def\id{ \mathop{id}\nolimits }
\def\h{ {\frak h} }
\def\e{ {\frak e} }
\def\G{ G }
\def\pinch{{ \mathop{{\rm pinch}} }}
\def\tuber{{ \bar\tau }}
%%%%
%%%%
\[
\begin{diagram}
\node[4]{ \K{8n+1} }
\\
\node[2]{ \KZ{8n-1}  } \arrow{e} \arrow{ene,t}{Sq^2}
   \node{E} \arrow{ne,b}{\Theta} \arrow{s,l}{\pi}
\\
\node{ \S\O X \^ \O X  } \arrow{e,t}{H_\mu} \arrow{ne,t}{\s(\a\@\a)}
   \node{ \Sigma \O X } \arrow{e,t}{\sigma} \arrow{ne,t}{\st}
       \node{ X }  \arrow{e,t}{\a^2}
           \node{ \KZ{8n}. }
\end{diagram}
\]
    
\[
\begin{diagram}
\node[3]{\O\S A} \arrow[2]{e,t}{\l_2}   
  \node[2]{\O^2 \( \S A \^ \S A \)} 
\\
\node[4]{\#}
\\
% Note: the next two lines are like
% \node{\O B}  \arrow[2]{e,t,1}{\d}     \arrow[2]{ne,t}{\O\(\p\)}
% but put a gap in first arrow to make room for crossing arrow
\node{\O B}  \arrow{e,t,-}{\d}  \arrow[2]{ne,t}{\O\(\p\)}
  \node{} \arrow{e}
    \node{F} \arrow[2]{e,t}{\h}  \arrow[2]{s,r}{\pi} \arrow[2]{n,r}{J}
      \node[2]{\O^2 \( B \^ \S A \)} \arrow[2]{n,r}{\O^2\(\p\^\id\)}
\\
\\
\node{A} \arrow[2]{ne,t}{\e} \arrow[2]{e,t}{f}  \arrow[2]{nne,t,1}{E}
  \node[2]{X}  \arrow[2]{e,t}{h}
    \node[2]{B.} 
\end{diagram}
\]

\[
\divide\dgARROWLENGTH by3
\begin{diagram}
\node[9]{\O S^5} 
\\
\\
\\
\node[8]{\scriptstyle\quad (\beta)}
\\
\node{\O\( M^5_{2\iota}\)} \arrow[4]{e,t}{\O\(\pinch\)}
   \node[4]{\O S^5} \arrow[2]{e,t,-}{\d} \arrow[4]{ne,t}{\O\(2\iota\)}
      \node[2]{} \arrow[2]{e}
         \node[2]{\G} \arrow[4]{e,t}{\h_2}
               \arrow[2]{s,r,-}{\pi} \arrow[4]{n,r}{J}
            \node[4]{J\(S^4\^S^4\)} 
\\
\\
\node[3]{J_2\( M^4_{2\iota}\)} \arrow[3]{e,t,3,-}{\d_2} \arrow[2]{ne,t}{\iota} 
   \node[3]{} \arrow{e}
      \node{\G_2} \arrow[4]{e,t,3}{\h_2} \arrow[2]{ne,t}{\iota}
         \node[2]{} \arrow[2]{s} 
            \node[2]{S^8} \arrow[2]{ne,b}{E}
\\
\node[4]{\scriptstyle (\alpha)} 
\\
\node{M^{12}_{2\iota}} \arrow[4]{e,t}{\tuber} \arrow[2]{ne,t}{\tau} 
   \node[4]{S^4} \arrow[4]{e,t}{\iota} \arrow[2]{ne,t}{\e} \arrow[4]{nne,t,3}{E}
      \node[4]{M^5_{2\iota}} \arrow[4]{e,t}{\pinch} 
         \node[4]{S^5} 
\end{diagram}
\]

\newpage
Example by Anders Thorup (thorup@math.ku.dk), originally done with a
package developed by himself and Steven Kleiman
(kleiman@math.mit.edu):
\[
\begin{diagram}
\node{H^k(B_G\times N;Q)=H^k_G(N;Q)}
      \arrow[2]{e,t}{f^*_j} \arrow[2]{s,l}{p^*} \arrow{se,t}{\tilde f^*}
   \node[2]{H^k_G(F_j;Q)} \arrow[2]{s,r}{q^*_j}
\\
\node[2]{H^k_G(M;Q)} \arrow{ne,t}{i^*_j} \arrow[2]{s,l,1}{i^*}
\\
\node{H^k(N;Q)}\arrow{e,t,-}{\tilde f^*_j=f^*_j}\arrow{se,b}{\tilde f^*=f^*}
   \node{} \arrow{e}
      \node{H^k(F_j;Q)}
\\
\node[2]{H^k(M;Q)} \arrow{ne,b}{i^*_j}
\end{diagram}
\]

\end{document}