Tagging equations with different symbols

Question

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

Have you tried using \renewcommand{\theequation}{\fnsymbol{equation}}? — TeXnician, Feb 28 '17 at 08:24
@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 08:27
Is there any reason why you would want to manually tag them? — TeXnician, Feb 28 '17 at 08:29
@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 08:29
@Texnician: Since I want to cite the equation in paragraph immediate after it and no after the paragraph ; so I thought it would be better to put some signs, insted of numbering them. — p Groups, Feb 28 '17 at 08:31
@pGroups What I meant was, there's no need for \mbox in your 'cheating' attempt. I'm not sure why , without the \mbox, you would still consider it as cheating, though. — Troy, Feb 28 '17 at 08:31
@Troy; you are right; I had not inserted dollar so showing error; but after putting dollar, in the tex file (without run) was showing red dollar symbols - I felt it is wrong; but actually no error comes, and so your command works. — p Groups, Feb 28 '17 at 08:33
I meant why you want to manually tag with symbols if latex can make this automatically (to see what I meant with the code look here). — TeXnician, Feb 28 '17 at 08:33

score 5 · Answer 1 · answered Apr 21 '17 at 18:13

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}

Tagging equations with different symbols

1 Answers1

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