Here is a tikz
version which automatically gets you all the flexibility inherent in tikz
such as rotating the symbol to be appropriate for the axis, adjusting the line style, colors, arrow style, etc...
![enter image description here](https://i.stack.imgur.com/sdX16.png)
Further Enhancement:
- Automatically rotate the symbol to be along the path.
- Provide a style setting that can be used to customize the symbol
Code:
\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\newcommand{\AxisRotator}[1][rotate=0]{%
\tikz [x=0.25cm,y=0.60cm,line width=.2ex,-stealth,#1] \draw (0,0) arc (-150:150:1 and 1);%
}
\begin{document}
\begin{tikzpicture}
\draw (0,0) -- (3,0) node [midway] {\AxisRotator};
\draw (0,0) -- (0,-3) node [midway] {\AxisRotator[rotate=-90]};
\draw (0,-3) -- (3,0) node [midway] {\AxisRotator[rotate=60]};
\end{tikzpicture}
%
\begin{tikzpicture}
\draw (0,0) -- (3,0) node [midway] {\AxisRotator[x=0.2cm,y=0.4cm,->,densely dotted]};
\draw (0,0) -- (0,-3) node [midway] {\AxisRotator[x=0.2cm,y=0.4cm,->,rotate=-90,blue, dashed]};
\draw (0,-3) -- (3,0) node [midway] {\AxisRotator[x=0.2cm,y=0.4cm,->,rotate=60, red ]};
\end{tikzpicture}
\end{document}
The MnSymbol package provides it.
\documentclass{article}
\usepackage{MnSymbol}
\begin{document}
So a rational map f: $V_1 \dashedrightarrow V_2$ is not a map at all;
\end{document}
![enter image description here](https://i.stack.imgur.com/ScRIG.jpg)
Best Answer
The package
mathabx
provides all arrows of this kind. The one you're looking for is\updownarrows
.For such questions, a good place to look at is the comprehensive LaTeX symbols list.
Note that
mathabx
redefines many symbols. An alternative is the following code, which produces updownarrows in a pure-latex fashion, but as you can see, the result is still not fully identical toamssymb
's\upuparrows
.A possible solution would be to redefine
\upuparrows
and\downdownarrows
as well :In comments, egreg proposed the following answer, for the same result (well, not technically the same), but with a cleaner code. It will probably give better spacing results if used within longer formulas :