I stumbled over this kind of arrows and can't find any reference to it (since I not even know how they're called).


Does anyone know the right command for those? Or are this constructed elements?
I stumbled over this kind of arrows and can't find any reference to it (since I not even know how they're called).


Does anyone know the right command for those? Or are this constructed elements?
\documentclass{article}
\usepackage{amssymb,amsmath}
\usepackage{centernot}
\begin{document}
$X \overset{\bullet}{\to} Y$
$X \overset{\bullet\mkern3mu}{\to} Y$
$X \overset{\scalebox{0.5}{$\bullet$}\mkern3mu}{\to} Y$
$X \overset{\raisebox{-1ex}{\scalebox{0.5}{$\bullet$}}\mkern3mu}{\to} Y$
$\nrightarrow$
$\not\rightarrow$
$\centernot{\rightarrow}$
\end{document}
yields

\mkern-3mu (within the braces) after the \bullet. the dot also looks too high, but that's harder to fix.
– barbara beeton
Jan 12 '13 at 21:53
\stackrel instead of \overset.
– yo'
Jan 13 '13 at 00:08
\stackrel{{}_\bullet}{\rightarrow} (doable with \overset the very same way). And you're right, the result is exactly same. Just that \overset does quite a lot of unnecessary things that \stackrel does not. As well, \stackrel seems to be semantically correct ("stack" something on a "relation" symbol).
– yo'
Jan 13 '13 at 18:47
\overset{\bullet}{\to}withamsmathwhould work; for the second one, look at thecenternotpackage. The canonical reference is How to look up a symbol – egreg Jan 12 '13 at 18:41amssymbpackage offers\nrightarrow. – Gonzalo Medina Jan 12 '13 at 18:48