How can I write a latex fraction without a bar?

Question

Possible Duplicate:
Separate long math text under sum symbol into different lines?

I'm trying to write a math formula like this:

\sum_{ \frac{n=0}{(n+k-i) \text{~even}} }^{k-i}

This looks just as I want it, but I don't want the bar between n=0 and (n+k-i) text.

I tried using the matrix env,

\sum_{ \begin{matrix}{n=0}\\{(n+k-i) \text{~even}}\end{matrix} }^{k-i}

But that looks really bad, because the (n+k-i) text is too large.

Answer 1

try

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\[
\sum_{\substack{n=0\\ (n+k-i)~\mathrm{even}}}^{k-i}
\]
\end{document}

maybe this is what you want to achieve.