Text Formatting ⇒ \underset inside \section won't compile

[farmerss]

Hi, I'm having trouble using an "\underset" command within a "\section" title. E.g. with the code

Code: Select all

%test.tex
\documentclass{article}
\usepackage{amsmath}
\begin{document}

\section{$\underset{}{}$}

\end{document}

I run "latex test" in the terminal, and get the output:

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This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian)
entering extended mode
(./test.tex
LaTeX2e <2009/09/24>
Babel <v3.8l> and hyphenation patterns for english, usenglishmax, dumylang, noh
yphenation, loaded.
(/usr/share/texmf-texlive/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/usr/share/texmf-texlive/tex/latex/base/size10.clo))
(/usr/share/texmf-texlive/tex/latex/amsmath/amsmath.sty
For additional information on amsmath, use the `?' option.
(/usr/share/texmf-texlive/tex/latex/amsmath/amstext.sty
(/usr/share/texmf-texlive/tex/latex/amsmath/amsgen.sty))
(/usr/share/texmf-texlive/tex/latex/amsmath/amsbsy.sty)
(/usr/share/texmf-texlive/tex/latex/amsmath/amsopn.sty)) (./test.aux)
! Argument of \@tempb has an extra }.
<inserted text> 
                \par 
l.8 \section{$\underset{}{}$}
                             
? 
Runaway argument?
\mathrel \else \relax \fi \fi \@nil \endgroup \let \noexpand \binrel@@ \ETC.
! Paragraph ended before \@tempb was complete.
<to be read again> 
                   \par 
l.8 \section{$\underset{}{}$}
                             
? 
[1] (./test.aux) )
Output written on test.dvi (1 page, 260 bytes).
Transcript written on test.log.

If I compile inside kile, I get a similar response:

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LaTeX finished with exit code 1
./test.tex:8:Argument of \@tempb has an extra } \section{$\underset{}{}$}
./test.tex:8:Paragraph ended before \@tempb was complete \section{$\underset{}{}$}

Any ideas why it wouldn't work? Variations like e.g. "\section{a}{b}", or with some other text wrapping the "\section" command, still fail. But if I remove the "\section", or remove the "\underset", then things compile ok.

(I'm using the latex that came either with ubuntu 11.04 or maybe with kile 2.0.85. But the problem occurs with compliation in the terminal. The amsmath.sty that appears to be loading says "version 2.13" in it.)

Any help most appreciated.

[Stefan Kottwitz]

Hi,

just use \protect:

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\section{$\protect\underset{}{}$}

Stefan

[farmerss]

Great, thanks! That works.