Source edit

\documentclass[a4paper]{article}
\usepackage[dvips,matrix,arrow,ps,color,line,curve,frame]{xy}
\usepackage{diagxy}

\thispagestyle{empty}

\begin{document}
$$\bfig
\square
/>`->>`<-{) }`^{ (}-->>/<900,500>%
[A`B`A/\mathrm{Ker}\,\varphi`\mathrm{Im}\,\varphi
;
\varphi`\pi`i`\widetilde\varphi]
\efig$$
\end{document}

This source is then proceeded through the commands :

latex source.tex
dvips source.dvi
ps2eps source.ps
pstopnm -portrait -xmax 260 source.eps
pnmtopng source.eps001.ppm > source.png

Summary edit

Licensing edit

I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.