I'd like to double underline in math-mode. I'm using uuline (package ulem) for this, but I have troubles with it. There is far too much free space below double-underlined characters. I don't have these problems with uline btw.
Here's a comparison of non-underlined, uline and uuline:

Code: Select all
\documentclass[a4paper]{article}
\usepackage{color}
\usepackage{ulem}
\begin{document}
\colorbox{green}{$r$}
\colorbox{green}{$\uline{r}$}
\colorbox{green}{$\uuline{r}$}
\colorbox{green}{$r_I$}
\colorbox{green}{$\uline{r}_I$}
\colorbox{green}{$\uuline{r}_I$}
\end{document}
Do you know what is causing this problem and how to solve it?
Thanks in advance!