How do I use LaTeX intertext in quarto?

[justsharan]

Description

Hey! I'm writing a statistics ebook in quarto, and I'd like to use \intertext within my align environments in LaTeX codeblocks to add text in-between. However, when I try to add it, this is what I see:

$$
\begin{align*}
    M_X(t) &= \E\left(e^{tX}\right) \\
    \intertext{We can expand this using LOTUS.}
    &= \sum_{x=0}^\infty e^{tx} e^{-\lambda} \frac{\lambda^x}{x!}\\
    &= e^{-\lambda} \sum_{x=0}^\infty e^{tx} \frac{\lambda^x}{x!} \\
    &= e^{-\lambda} \sum_{x=0}^\infty \frac{\left(\lambda e^t\right)^x}{x!} \\
    \intertext{Due to the Maclaurin series of $e^x$ (check above), we can simplify the summation to $e^{\lambda e^t}$. The Maclaurin series of $e^x$ converges for all $x\in \mathbb{R}$, so it can be used here.}
    &= e^{-\lambda} e^{\lambda e^t}\\
    &= e^{\lambda e^t - \lambda} \\
    &= e^{\lambda (e^t-1)}
\end{align*}
$$

Meanwhile, the expected behavior in a true LaTeX file would be:

[mcanouil]

Use keep-tex: true in your YAML configuration file or YAML front matter.
Then look at the latex intermediary file and debug it.
Once you've found how to fix the issue, add that fix using include-in-* and/or LaTeX partials.

[justsharan]

I forgot to mention that I'm rendering the ebook as html, not pdf. I believe keep-tex may be a pdf-only option?

[cscheid]

I forgot to mention that I'm rendering the ebook as html

In that case, you need to make sure that intertext is supported by MathJax (or whatever other html-math-method you might be using). That isn't really a thing that Quarto knows about.

[cderv]

you need to make sure that intertext is supported by MathJax

And I don't think they have it

• Support \intertext and \shortintertext in align* mathjax/MathJax#736

@justsharan here is the doc about LaTeX equation in HTML document:
https://quarto.org/docs/output-formats/html-basics.html#latex-equations

You have several options and what you are using is rendered by those.

Hope it helps