frown and mathop/stackrel/overset

I need something like \stackrel{\frown}{MM'} to express the fact that MM' is some path. But I am not really satisfied by the look of the result. The \frown is too high. Would you please have a suggestion?

Edit 1: I just discovered that the font I'm using, ie kpfonts, offers a nice widearc command which suits my needs.

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You may try \wideparen from the yhmath package:

\usepackage{yhmath}
...
$\wideparen{MM'}$


In case you don't want to change the largesymbol font, it's possible to load only the \wideparen accent:

\documentclass{article}
\DeclareSymbolFont{yhlargesymbols}{OMX}{yhex}{m}{n}
\DeclareMathAccent{\wideparen}{\mathord}{yhlargesymbols}{"F3}

\begin{document}
$\wideparen{MM'}$
\end{document}


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You can use arcs package for this. It provide \overarc command. But this package seems broken on my computer. :(

You can also use \wideparen provided by yhmath font package. yhmath is compatible with default CM fonts.

\documentclass{article}
\usepackage{yhmath}

\begin{document}
$\wideparen{MM'}$
\end{document}


MnSymbol package, mathdesign package, and maybe some other math font packages, also provide \wideparen. It would be great if you use MinionPro with MnSymbol, or Utopia with mathdesign fonts.

For example:

\documentclass{article}
\usepackage[utopia]{mathdesign}

\begin{document}
$\wideparen{MM'}$
\end{document}


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In recent distributions, yhmath comes with a corresponding Type1 font. – egreg Apr 10 '11 at 14:49
@egreg: Sorry, I didn't notice it. Then it's okey to use yhmath. BTW, \adots in yhmath is wrong for different font size, one should use \iddots from mathdots package instead. That's another reason I don't like yhmath. – Leo Liu Apr 10 '11 at 14:55
Well, and amatrix env. in yhmath is not compatible with latest amsmath. Pity. It should be \newenvironment{amatrix}{\left\langle\begin{matrix}}{\end{matrix}\right\rangle}‌​ – Leo Liu Apr 10 '11 at 15:21
I'd like to avoid another package. – pluton Apr 10 '11 at 15:31
@pluton: See revision 2. tex.stackexchange.com/posts/15473/revisions – Leo Liu Apr 11 '11 at 4:49
\documentclass{article}
\usepackage{graphicx,amsmath}
\newcommand\bigfrown[2][\textstyle]{\ensuremath{%
\array[b]{c}\text{\scalebox{2}{$#1\frown$}}\$-1.3ex]#1#2\endarray}} \begin{document} foo \bigfrown{MM'} bar \[\int\limits_{\protect\bigfrown[\scriptstyle]{MM'}}$

\end{document}


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thank you but it does not work for an integral \int_{\bigfrown{MM'}} – pluton Apr 10 '11 at 15:04
@pluton: sure, as always \int_{\protect\bigfrown{MM'}}. However, the \bigfrowncan also be defined as a protected definition. – Herbert Apr 10 '11 at 15:13
correct but it does not scale down as it should – pluton Apr 10 '11 at 15:30
@pluton: true, could also be done by the command itself, but that need some more work. See edited example for a simple workaround when it is only needed once – Herbert Apr 10 '11 at 15:45

Accent seems like a way to go (example with XITS and XeTeX, in Plain):

\def\frown{\XeTeXmathaccent"0"1"23DC}
$$\frown{MM'} \int\limits_{\frown{MM'}}$$
\bye


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\DeclareFontEncoding{FMX}{}{}%%%
\DeclareFontSubstitution{FMX}{futm}{m}{n}%%%
\DeclareSymbolFont{largesymbols}{FMX}{futm}{m}{n}
\DeclareMathAccent{\widearc}{\mathord}{largesymbols}{216}


Use

$\widearc{MM'} + \int\limits_{\widearc{MM'}}$

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In ConTeXt, this accent is provided by \overparent:

\starttext
$\overparent{MMM}$

\startformula
\int_{\overparent{MM'}} f(x) dx
\stopformula

\stoptext


which gives

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I don't know if in practice (I'm not mathematician, sorry) someone will need ever arcs wider than 4 or 5 lowercase characters. If this could be a real scenario, then \widearc of kpfonts, or \wideparen of yhmath or mathdesign, or \bigfrown, probably are not the best solution, since like others extensible accents, are unable to expand too much:

This problem seem well solved with \overparent in Aditya answer, but this require ConTeX. For pdflatex, I think that a decent alternative could be \overgroup from mathabx package:

\documentclass{minimal}
\usepackage{mathabx}
\begin{document}
$\overgroup{M'}$
$\overgroup{MM'}$
$\overgroup{MMMM'}$
$\overgroup{MMMMMMMM'}$
\end{document}

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The context solution replies on the font, so it should also work with lualatex – Aditya Nov 5 '13 at 3:24