# Tagging equations with three \ast

I want to tag some equations with \ast, for \ast and \ast \ast it's good, but for the third I would like to have the three \ast placed like in a triangle, so two \ast at the bottom and the third in the middle about above the base two.

$$\tag{\ast} \label{eq-1}$$
$$\tag{\ast \ast} \label{eq-2}$$
$$\tag{\threeast} \label{eq-3}$$


because $\ast\ast\ast$ is too long

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Just as a note, you shouldn't use $$x$$ use $x$ instead. – Roelof Spijker Oct 19 '11 at 9:36
I use \begin{equation*}, \begin{align*}, \begin{multline} dependening on the situation, I just put  to make the code sample short – Johannes L Oct 19 '11 at 9:40
You shouldn't actually write $\ast\ast\ast$ or $***$ anyway, because TeX interprets the middle one as being an operator and adds spaces. Write $\ast{\ast}\ast$ or $*{*}*$ instead to hide its operator-ness. – Ryan Reich Oct 19 '11 at 14:26

Here's my attempt. It's not ideal. And it borrows from Ian Thompson's answer in its use of the two commands, one for the symbol, one to protect it. It is more compact that Ian's and uses \shortstack rather than tabular. EDIT: I've changed the adjustments to be in ex rather than pt on egreg's suggestion. I've also got rid of the \ensuremath{\displaystyle… stuff I had before which I thought I needed...

\newcommand\iiiastsym{\raisebox{-.5ex}{\shortstack{%
$\tag{\ast \ast} \label{eq-2}$
$\label{eq-3} \tag{\threeast}$
\end{document}

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You could try the following definition of \threeast (which requires the use of the amsmath package):

\newcommand{\threeast}{\ensuremath{\overset{\textstyle\ast}{\ast\ast}}}


You may wish to lower the entire construct by a couple of points in order to improve its vertical positioning.

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overset requires amsmath. It's worth making that clear... – Seamus Oct 19 '11 at 11:20