Subject: Re: bug#78566: preview

From: Arash Esbati <[email-masked]>
Date: Mon, 26 May 2025 14:17:24 +0200

"Pichler, Alois" <[email-masked]> writes:

> The LaTeX-package ‘mathtools’ has the useful setting ‘showonlyrefs’ to
> suppress equations numbers, which are not referenced in the text.
> AUCTeX’s preview currently ignores this setting. Here is a minimal example:
> \usepackage{mathtools}
> \mathtoolsset{showonlyrefs}
>
> \begin{equation}\label{eq:1}
>    x=3   %   <--   preview will display “x=3”, not “x=3   (1)”, etc.
> \end{equation}
> In~\eqref{eq:1}, ... % equation will be numbered, because referenced here

I confirm the behavior you describe.  I'm not sure if it is possible to
easily fix it.  mathtools.sty seems to hack LaTeX internals do achieve
the behavior, since it needs some additional LaTeX runs to get
everything right (I only had a brief look at the source).  I fear this
will end up as "wontfix" if others don't have a good idea.

Best, Arash