Spacing before subequations

[AlexanderZeilmann]

Summary

There is a bug in the subequations environment that causes a too large spacing if the line before fills the entire paragraph. This can be fixed by adding

\usepackage{etoolbox}
\preto\subequations{\ifhmode\unskip\fi}

to the preamble.

Maybe you want to add this to kaobook.

MWE

\documentclass{kaobook}

% \usepackage{etoolbox}
% \preto\subequations{\ifhmode\unskip\fi}

\begin{document}

A line that does not fill the paragraph has normal spacing
\begin{subequations}
    \begin{alignat}{1}
        a \\
        b
    \end{alignat}
\end{subequations}
A line that does fill the paragraph has too much spacing before the eq.
\begin{subequations}
    \begin{alignat}{1}
        a \\
        b
    \end{alignat}
\end{subequations}
A line after the equation.

\end{document}

[fmarotta]

Done, thanks!

[MevenBertrand]

@fmarotta I get an error on my end with your fix, it seems to be because you need to put the fix after importing amsmath rather than before. Can you confirm the issue comes from your side? The CI after commit deaac8ade99033ebddc46befb702495e32c80fb0 and PR #221 all agree that there’s an issue with subequation introduced by that commit.

[fmarotta]

Sorry, my bad. I've merged #221, which should fix the problem.