# Uniform convergence symbol (arrow on top of arrow, same size)

I am looking for a symbol that looks like two arrows of the same size, one on top of the other with (possibly) a letter on top, this is my paint sketch of it:

I've tried something like

\xrightarrow{\xrightarrow{n}}


and similar combinations but it always makes one arrow smaller.

I've seen this symbol used to say that a sequence of functions converges uniformly to another function.

If you don't need it in smaller math styles, then this could work...

\documentclass{article}
\usepackage{stackengine,graphicx}
\stackMath
\newcommand\frightarrow{\scalebox{1}[.4]{$\rightarrow$}}
\newcommand\darrow[1][]{\mathrel{\stackon[1pt]{\stackanchor[1pt]{\frightarrow}{\frightarrow}}{\scriptstyle#1}}}
\begin{document}
$A\darrow[n] B$
\end{document}


Here is a composite alternative

\documentclass{article}
\usepackage{stackengine,graphicx,amssymb}
\stackMath
\newcommand\frightarrow{\scalebox{1}[.3]{$\rule[.45ex]{2ex}{1.5pt}% \kern-.2ex{\blacktriangleright}$}}
\newcommand\darrow[1][]{\mathrel{\stackon[1pt]{\stackanchor[1pt]{\frightarrow}{\frightarrow}}{\scriptstyle#1}}}
\begin{document}
$A\darrow[n] B$
\end{document}


"Cheating" would be writing it as

f_n(x)^\rightarrow_\rightarrow f(x)


which results in the following formula: