# Problems with '\rightrightarrows' and other a arrow symbols

I'm trying to define a mathematical correspondence. The double-arrow symbol is supposed to be \rightrightarrows. But when I run it LaTex tells me that it is not defined. This also happens with other arrow symbols (like \circlearrowleft) that are supposed to be available.

Can anyone help me? Do you know if I need a package for those symbols? Thanks in advance!

• ,@JesúsSantxezIbrahim -- Yes, you need to load amssymb package – AboAmmar Aug 31 '16 at 22:18
• Isn't it \leftrightarrow? – David G. Stork Aug 31 '16 at 23:33
• The double arrow, if I understand well, is \Rightarrow. \circlearrowleft comes with amsfonts or amssymb. – Bernard Sep 1 '16 at 1:27
• @JPi: I beat you by 3 seconds! – Bernard Sep 1 '16 at 1:47
• @JPi: The point is not that I beat you – I don't care to beat any one – but the 3 seconds… – Bernard Sep 1 '16 at 1:50

Finding a particular LaTeX symbol or character can be very easy. Have a look at “How to look up a math symbol?” for ideas on how you can achieve this. The linked question lists two especially helpful tools; namely the Comprehensive LaTeX symbols list and a web-based software known as Detexify. The latter is also available for smart phones.

If you try one of the above tools, you will discover that the symbols you need require using the amssymb package. Here are some examples:

\documentclass{article}
\usepackage{amssymb}
\begin{document}

\begin{tabular}{ccc}
$\circlearrowleft$  & $\leftleftarrows$      & $\rightleftarrows$     \\
$\circlearrowright$ & $\leftrightarrows$     & $\rightrightarrows$    \\
$\curvearrowleft$   & $\leftrightsquigarrow$ & $\rightsquigarrow$     \\
$\curvearrowright$  & $\Lleftarrow$          & $\Rsh$                 \\
$\dashleftarrow$    & $\looparrowleft$       & $\twoheadleftarrow$    \\
\end{tabular}

\end{document}