[texhax] Strange interaction with revtex

[Philip Taylor (Webmaster, Ret'd)]

It's the "em"; somehow RevTeX is selecting the null font.
** Phil.
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Michael Barr wrote:
> \documentclass{revtex4}
> \newdimen\ul
> \ul=.01em
> \showthe\ul
> \begin{document}
> \end{document}