# How to make a commutative diagram smooth?

I have drawn the following diagram:

using the following command:

\documentclass[11pt,twoside,a4paper]{book}

\usepackage[margin=1.5in]{geometry}
\usepackage{xypic}

\begin{document}
\xymatrix{
A\ar[rrrr]\ar[rrdd] && && B\ar[lldd] \\
\\
&& C &&
}
\end{document}


But this diagram is not smooth, especially the arrow AC and BC. How can I make it smooth?

• I have a smooth lines compiling your document. How do you compile and what viewer you use? – m0nhawk Apr 27 '13 at 14:27
• It's important to know what TeX system you're using and how you get final output; is it pdflatex or latex+dvips+ps2pdf? In any case, you seem to have an outdated TeX distribution. – egreg Apr 27 '13 at 14:32
• I have compiled it through 'pdflatex' with 'kile'. I am using 'Document viewer' to view PDF file. – Md Kutubuddin Sardar Apr 27 '13 at 14:37
• @MdKutubuddinSardar You probably suffer from having the very outdated TeX Live 2009 provided by Ubuntu. Try updating to TeX Live 2012. – egreg Apr 27 '13 at 15:35

The diagram is fine. I've compiled your code on MacTeX 2012 with pdflatex: