[Tex/LaTex] Stacked left and right arrows

articlesymbols

Of all the arrows available, I can't seem to find something that looks like this:

enter image description here

Is there a reason for this? The \leftrightharpoons is the closest alternative. But I would rather have the arrows look like in the image above.

Best Answer

Here's a code for it:

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\newcommand{\lrarrow}{\mathrel{\mathpalette\lrarrow@\relax}}
\newcommand{\lrarrow@}[2]{%
  \vcenter{\hbox{\ooalign{%
    $\m@th#1\mkern6mu\rightarrow$\cr
    \noalign{\vskip1pt}
    $\m@th#1\leftarrow\mkern6mu$\cr
  }}}%
}
\makeatother

\begin{document}

$A\lrarrow B_{\lrarrow}$

\end{document}

enter image description here