LaTeX packages #mathjax


The book I'm currently harvesting uses a couple LaTeX packages for its MathJax equations that LibreTexts doesn’t. It uses xparse to define commands with optional arguments, bussproofs to display proof trees, and amssymb for formatting text as sans serif italics. Is there any way to support those on LibreTexts? Or should I work around it?
(The text has a complete list of the different packages used here, but those are the only three I've gotten stuck on.)

Here are some examples:
On one of the pages I harvested here, the text uses defines an \lexists command for the ∃ symbol. Sometimes the command just has the symbol alone, like in heading, but other times it takes optional arguments in brackets, like in the paragraph beneath.
You can see in the original pdf that it's supposed to be ∃x A(x), but LibreTexts is displaying it with the brackets.

I've been defining commands in a template here, and can get the symbol to show up using this:
\(\def\lexists{ {\exists} }\)
However, I haven't been able to define optional arguments, like the text does here:
(If that can't be incorporated into LibreTexts, I could work around it by going through the pages and rewriting those kinds of commands without brackets.)

The previous example page also has proof trees that use the bussproofs package. You can see in the pdf that one is supposed to look like this:
The equation didn't translate over when I used pandoc to convert to html, but here's how it was written in the original Latex file:
\AxiomC{$\Atom{!A}{t}$} \RightLabel{\Intro{\lexists}} \UnaryInfC{$\lexists[x][\Atom{!A}{x}]$} \DisplayProof \hfill \AxiomC{$\lexists[x][\Atom{!A}{x}]$} \AxiomC{[$\Atom{!A}{a}$]$^n$} \DeduceC{$!C$} \DischargeRule{\Elim{\lexists}}{n} \BinaryInfC{$!C$} \DisplayProof

It uses custom commands like AxiomC that aren't rendering on LibreTexts.
I tried working around it by just using the mathpix snipping tool, but it couldn't get the layout right.
(If we can't incorporate bussproofs into LibreTexts, I could try and figure out how to approximate it with standard mathjax, or just take screenshots of the equations.)

On this page, there's a \Obj command that is supposed to be defined with the amssymb package so it can use \mathsfit.
You can see on the pdf that it's supposed to apply italics and sans serif formatting.
As far as I can figure out, regular mathjax can do italics (with \mathit) or sans serif (with \mathsf), but not both at once. I'm not sure how to handle this without that package.


I looked into it a little more:
  • xparse: The xparse package isn't on the list of LaTeX packages supported by Mathjax, and the actual command we need from it, \DeclareDocumentCommand, isn't in the list of supported LaTeX commands in Mathjax, so I don’t think that's going to be easy to incorporate into LibreTexts. I will probably just rewrite the equations that use optional commands.
  • bussproofs: It looks like bussproofs is one of the LaTeX packages that Mathjax supports, so that should be possible to incorporate into LibreTexts. (I'm just not sure how - I'm not sure where I would go to change the site's Mathjax configuration, and whether I would have the permission level to do that.)
  • amssymb: The amssymb package isn't on the supported-LaTeX-packages list, but the actual command we need, \mathsfit, is in the list of supported commands. It's not working for me when I try to use it on LibreTexts, though, so I'm not sure what's going on there.