# A better notation to denote arcs for an American high school textbook

For years, I've been using a hobbled together command to get the arc notation as used in the textbooks adopted by high schools in my area. I'm not really all that pleased with the result: it's just barely tolerable. I figured someone in the community here might have a better solution to what I've been getting by with for several years.

\documentclass{article}
\usepackage{amsmath,amssymb}
%% my poor man's solution to arc notation
\newcommand{\tarc}{\mbox{\large$\frown$}}
\newcommand{\arc}[1]{\stackrel{\tarc}{#1}}
%%
\pagestyle{empty}
\begin{document}

\begin{align*}
\arc{AC} \\
\arc{ICK}
\end{align*}

\end{document}


• Check texdoc symbols-a4 for \wide and especially \wideparen. – Qrrbrbirlbel Feb 4 '13 at 3:13
• Did you see the related question frown and mathop/stackrel/overset? You can use \widearc with the kpfonts or fourier packages, but these change your fonts. \wideparen from yhmath or a few other packages, mentioned there, also works. – Nick Matteo Feb 4 '13 at 3:16

A solution along the lines of Werner's, but that avoids its shortcomings, first of all the dependency on tipa:

\documentclass{article}
\usepackage{graphicx}

\makeatletter
\DeclareFontFamily{U}{tipa}{}
\DeclareFontShape{U}{tipa}{m}{n}{<->tipa10}{}
\newcommand{\arc@char}{{\usefont{U}{tipa}{m}{n}\symbol{62}}}%

\newcommand{\arc}[1]{\mathpalette\arc@arc{#1}}

\newcommand{\arc@arc}[2]{%
\sbox0{$\m@th#1#2$}%
\vbox{
\hbox{\resizebox{\wd0}{\height}{\arc@char}}
\nointerlineskip
\box0
}%
}
\makeatother

\begin{document}

$\arc{AC}$ $\arc{BAD}$ $\arc{ICK}$ $\arc{GOOD}_{\arc{xyz}}$

\end{document}


A different solution with the yhmath font:

\documentclass{article}

\DeclareFontFamily{OMX}{yhex}{}
\DeclareFontShape{OMX}{yhex}{m}{n}{<->yhcmex10}{}
\DeclareSymbolFont{yhlargesymbols}{OMX}{yhex}{m}{n}
\DeclareMathAccent{\wideparen}{\mathord}{yhlargesymbols}{"F3}

\begin{document}

$\wideparen{AC}$ $\wideparen{BAD}$ $\wideparen{ICK}$ $\wideparen{GOOD}_{\wideparen{xyz}}$

\end{document}


• Always something to learn from your answers. Thank you. – A.Ellett Dec 27 '15 at 19:01

tipa's \texttoptiebar looks useable:

\documentclass{article}
\usepackage{graphicx,tipa}% http://ctan.org/pkg/{graphicx,tipa}
\newcommand{\arc}[1]{{%
\setbox9=\hbox{#1}%
\ooalign{\resizebox{\wd9}{\height}{\texttoptiebar{\phantom{A}}}\cr#1}}}
\begin{document}
\end{document}

• This is my preferred solution, however note that the command \arc is already part of other packages such as "unitsdefs", "eepic", "pict2e". I suggest using \ark instead. – c05772 Jun 25 '15 at 19:23
• There are so many errors here! Box 9 should be assigned globally (or box 8) should be used; \ooalign must be enclosed in a group. The text is not in math mode as required in the question. – egreg Dec 26 '15 at 20:39

I know this is an old question, but I thought I add my version. The reason I do this is because I am using KaTeX to develop for the web, so importing special packages is not possible. The following is a modification of the code in the original question. It does not use extra packages, it moves the arc closer to the text. An optional argument can be used for horizontal positioning of the arc. I know it is not ideal, but as I said, in KaTeX it is not an option to load extra packages.

\documentclass{article}
\usepackage{amsmath,amssymb}
%% modified solution to arc notation
\newcommand{\tarc}{\mbox{\large$\frown$}}
\newcommand{\arc}[2][-3ex]{{#2}{\kern #1{\raisebox{1.5ex}{\tarc}}}}
%%
\pagestyle{empty}
\begin{document}
\begin{align*}
&\arc{AC} \\