皱眉与箭头

Question

我想知道数学模式中是否有这样的符号，\frown但末端有一个箭头。像这样：

（我就是喜欢用油漆哈哈哈）谢谢！:)

Answer 1

\documentclass[12pt]{report} 
\usepackage[T1]{fontenc} 
\usepackage{mathtools,mathabx}
\newcommand\AR[1]{\makebox[0pt][l]{$#1$}\kern0.5em\raisebox{1.5ex}{$\curvearrowright$}}
\begin{document}

$\AR{AB}$ \Huge\AR{AB}

\end{document}

Answer 2

另一个解决方案是TiKz扩展两个以上的字母：

\documentclass[]{article}
\usepackage[utf8]{inputenc}
\usepackage{tikz}

\newcommand\source[1]{%
    \tikz[remember picture,baseline,inner sep=0pt] {%
        \node [name=source,anchor=base]{$#1$};
    }%
    \setcounter{target}{0}
}
\newcounter{target}
\newcommand\target[1]{%
    \tikz[remember picture,baseline,inner sep=0pt] {%
        \node [name=target-\thetarget,anchor=base]{$#1$};
    }%
    \stepcounter{target}%
}
\newcommand\drawarrows{
    \tikz[remember picture, overlay, bend left=45, -latex] {
        \foreach \i [evaluate=\i as \n using int(\i-1)] in {1,...,\thetarget} {
            \draw ([xshift=-1mm,yshift=0.5mm]source.north) to ([xshift=1.5mm,yshift=0.5mm]target-\n.north);
        }
    }
}

\begin{document}
  $$  \source{A}\target{B}  \drawarrows $$
  $$  \source{A} B \target{C}  \drawarrows $$
  $$  \source{A} BC \target{D}  \drawarrows $$
\end{document}