# A circular version of \underbrace or \widehat

I'm new to LaTeX and am searching for a function that acts like \underbrace or \widehat but is circular (I don't want the pointed middle part). Does such a function exist? I tried using Detexify but I didn't find what I was looking for. I would be using it for text.

Perhaps the macro \wideparen from yhmath package could be a solution, but it is not really circular and it does not scale very well with the fontsize, in my point of view.

\documentclass{article}

\usepackage{yhmath}

\begin{document}
$\wideparen{E = mc^2}$
\end{document}


• Is there a way to bring that curved line to the bottom? – LiberatedDreamer Nov 15 '14 at 4:42
• @LiberatedDreamer: You asked for something like \widehat, that's above the text. You can try \undergroup from MnSymbol{} package – user31729 Nov 15 '14 at 4:45
• Thanks. I also found some more useful info here tex.stackexchange.com/questions/15468/… – LiberatedDreamer Nov 15 '14 at 5:06

Here is a simple solution that uses pst-node. I define an \overarc and an underarc commands, both with an optional argument, the angle between the arc and the chord determined by the extremities of the arc.

Unfortunately, for some reason, it doesn't work with auto-pst-pdf, so that you have to compile either with the chain latex -> dvips -> pstopdf or with xelatex.

\documentclass[12pt]{article}

\usepackage{ifxetex, ifluatex}
\ifxetex\else \ifluatex\else\usepackage[utf8]{inputenc}\fi\fi
\usepackage{amsmath, amssymb, amsfonts}
\usepackage{fourier}
\usepackage{pst-node}
\usepackage{auto-pst-pdf}

\newcommand\overarc[2][30]{\psDefBoxNodes{F}{\mkern-2mu#2\mkern-2mu}\pcarc[offset=2pt, arcangle=#1]{c-c}(F:tl)(F:tr) }
\newcommand\underarc[2][30]{\psDefBoxNodes{F}{\mkern-2mu#2\mkern-2mu}\pcarc[offset=2pt, arcangle=#1]{c-c}(F:br)(F:bl) }

\begin{document}

$\overarc{E = mc²} \qquad \underarc{E = mc²}$%

\end{document}