# “Broken” arrow symbol

In his pretty awesome book “Undergraduate Algebraic Geometry” M. Reid uses (e.g. see page 4) symbol of “broken” arrow (which looks quite a like dash+space+short arrow : “- →”) for partially defined maps. What is the most suitable way to produce it in LaTeX? I looked through “The Comprehensive LaTeX Symbol List” but didn't fined something similar.

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possible duplicate of How to look up a math symbol? (cf. Artem's comment to Psirus's answer. –  doncherry Dec 18 '11 at 10:41
Btw, Detexify service didn't work for this. –  Artem Pelenitsyn Dec 18 '11 at 19:53

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}


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Oops, I missed it when looked through Comprehensive List. Thanks! –  Artem Pelenitsyn Dec 18 '11 at 10:16

You can also use the usual overkill option of tikz which then gives you all the flexibility inherent in tikz. Here are a few of the possible options:

\documentclass{article}
\usepackage{tikz}

\newcommand*{\DashedArrow}[1][]{\mathbin{\tikz [baseline=-0.25ex,-latex, dashed,#1] \draw [#1] (0pt,0.5ex) -- (1.3em,0.5ex);}}%

\begin{document}
$V_1 \DashedArrow V_2$\par

\medskip
$V_1 \DashedArrow[densely dashed ] V_2$\par
$V_1 \DashedArrow[dotted ] V_2$\par
$V_1 \DashedArrow[densely dotted ] V_2$\par
$V_1 \DashedArrow[densely dashdotted] V_2$\par

\medskip
$V_1 \DashedArrow[->,densely dashed ] V_2$\par
$V_1 \DashedArrow[->,dotted ] V_2$\par
$V_1 \DashedArrow[->,densely dotted ] V_2$\par
$V_1 \DashedArrow[->,densely dashdotted] V_2$\par
\end{document}

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While MnSymbol provides \dashedrightarrow, it actually provides a whole host of math symbols as an entire font, which might have an unwanted effect. As such, it is possible to create your own \dashedrightarrow:

\documentclass{article}
\usepackage{color}% http://ctan.org/pkg/color
\makeatletter
\newcommand{\dashedrightarrow}[1][2pt]{%
\settowidth{\@tempdima}{$\rightarrow$}\rightarrow% typeset arrow
\makebox[-\@tempdima]{\hskip-1.5ex\color{white}\rule[0.5ex]{#1}{1pt}}% typeset overlay
}
\makeatother
\begin{document}
\begin{tabular}{lc}
\verb|\rightarrow|: & $V_1 \rightarrow V_2$ \\
\verb|\dashedrightarrow|: & $V_1 \dashedrightarrow V_2$ \\
\verb|\dashedrightarrow[4pt]|: & $V_1 \dashedrightarrow[4pt] V_2$
\end{tabular}
\end{document}


The above \dashedrightarrow[<len>] overwrites \rightarrow with a white \rule in the middle of the operator. The optional parameter provides a means to increase the dashed-ness, with a default of 2pt.

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