\documentclass[twocolumn]{article}
\NeedsTeXFormat{LaTeX2e}[1995/06/01]
\RequirePackage[dvips,all]{xy}

\begin{document}

\title{ \Xy-pic Debian Test }
\author{ Erick C.P.\ Branderhorst\quad<branderhorst@heel.fgg.eur.nl>\thanks{%
    Dept. General Surgery, University Hospital Rotterdam ``Dijkzigt'',
    The Netherlands.}}

\date{\today}
\maketitle

This file is part of the Debian ``xypic'' package. It's included for
test purposes. You should be able to ``run'' this file through \LaTeX
or \Xy\LaTeX with the commands \verb+latex+ or \verb+xylatex+.

The next part contains an example ``stolen'' from the xyguide which
comes with this distribution. The sources of the guide and the
reference guide aren't included with this distribution because it's
takes quite some processor time to run these through \verb+(xy)latex+.

\Xy-pic is a package for typesetting graphs and diagrams using Knuth's
\TeX\ typesetting system.  \Xy-pic works with most of the many formats
available, , plain \TeX, \LaTeX, and .  Several styles of input for
various diagram types are supported; they all share a mnemonic
notation based on the "logical composition of visual components".

\xymatrix{
 U \ar@/_/[ddr]_y \ar[dr] \ar@/^/[drr]^x \\
  & X \times_Z Y \ar[d]^q \ar[r]_p
                 & X \ar[d]_f            \\
  & Y \ar[r]^g   & Z                     }
\end{document}