# Latex arrow hook up

Can anyone tell me how to write \hookuparrow in Latex? I know that writing $\hookrightarrow$ gives us the arrow to the right but for up and down arrows it is not true, maybe I need some package ?

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Welcome to TeX.sx! Surely this post could help you. –  Corentin Dec 16 '12 at 18:19

\documentclass{article}
\usepackage{graphicx}
\newcommand{\hookuparrow}{\mathrel{\rotatebox[origin=c]{90}{$\hookrightarrow$}}}
\newcommand{\hookdownarrow}{\mathrel{\rotatebox[origin=c]{-90}{$\hookrightarrow$}}}
\begin{document}
\noindent
$a\hookrightarrow b$

\noindent
$a\hookuparrow b$

\noindent
$a\hookdownarrow b$
\end{document}


You can adjust the center (origin) of rotation using either t or b in \rotatebox[origin=c] as per your needs.

If the hook is wanted on the other side, as noted by Barabara Beeton, You may either reflect the arrow:

\newcommand{\hookuparrow}{\mathrel{\rotatebox[origin=t]{-90}{\reflectbox{$\hookrightarrow$}}}}
\newcommand{\hookdownarrow}{\mathrel{\rotatebox[origin=t]{90}{\reflectbox{$\hookrightarrow$}}}}


or use \hookleftarrow:

\newcommand{\hookuparrow}{\mathrel{\rotatebox[origin=t]{270}{$\hookleftarrow$}}}
\newcommand{\hookdownarrow}{\mathrel{\rotatebox[origin=t]{90}{$\hookleftarrow$}}}

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if the hook is wanted on the other side for some reason, the \hookleftarrow can be substituted with appropriate change in direction (270 instead of 90 should do it). i don't know what such a change might signify, and would be interested in finding out. –  barbara beeton Dec 16 '12 at 18:32