Tagging equations with different symbols [closed]

I want to put some different symbolic notations after some equations such as $*$, $\dagger$ (see image below), $\ddagger$ etc.

I did the following

\begin{equation*}
a+b=c  \tag{*}
\end{equation*}


Output was as expected:

For next equation, I wanted to use $\dagger$, and I did following:

\begin{equation*}
p+q=r  \tag{\dagger}
\end{equation*}


This produced some errors. I then replaced it in following cheating way:

\begin{equation*}
p+q=r  \tag{ \mbox{ $\dagger$ } }
\end{equation*}


This then showed following output as expected:

Question: So to put the sign of second image, I had to do go in process

[equation mode] --> [ text mode ] -- > [equation mode]

i.e. first -; inside it use \mbox{ }; inside it use dollar sign. Isn't this a cheating? What should be correct way to put this sign?

• Just \tag{$\dagger$} will do, no? – Troy Feb 28 '17 at 8:21
• Have you tried using \renewcommand{\theequation}{\fnsymbol{equation}}? – TeXnician Feb 28 '17 at 8:24
• @Troy: it was showing errors (I mentioned this; and so finally I did a cheating, which worked!). TeXnician, I have not used it. – p Groups Feb 28 '17 at 8:27
• Is there any reason why you would want to manually tag them? – TeXnician Feb 28 '17 at 8:29
• @Troy: sorry; your answer works; actually, when I put dollar sign inside tag, then it showed in red color, so I felt it will be wrong; but it works. Thanks – p Groups Feb 28 '17 at 8:29

The argument of the \tag{<label>} command from the amsmath package is in text mode by default. This is why if you try \tag{\dagger}, you get Missing \$ inserted-like errors.

If you want to tag them with a mathematical symbol, you need to enclose the symbol in a math environment, like $$...$$. The \mbox is not necessary.

\documentclass[]{article}
\usepackage{amsmath}

\begin{document}
Tagging in text mode:
\begin{equation*}
a+b=c  \tag{*}
\end{equation*}
Tagging in math mode (symbols):
$p+q=r \tag{$$\dagger$$} % <------- Note the math environment$
\end{document}