spacing in `align` environment 3rd column is incorrect for minus sign

[hbghlyj]

Issue Summary

4-column align environment has columnalign right left right left

\begin{aligned}
-L&=A E+C F&-M&=A F+C G\\
-M&=B E+D F&-N&=B F+D G .
\end{aligned}

For LaTeX in the third column, there is little space after negative sign	For MathJax in the third column, there is normal space after negative sign

I notice <mi></mi> prepended by MathJax

Technical details:

• MathJax Version: 3.2

[dpvc]

The <mi></mi> is being added too aggressively. I will make a PR to fix the problem. In the meantime, you could use {-}M and {-}N instead to prevent the extra spacing.