mathpix-markdown-it: theorem environments not supported

TL;DR

Use the documented syntax from doc/theorems.md for theorem, lemma, proof, and other theorem-like environments. Update to a release that includes it and use the documented syntax.

Steps

1. TL;DR: mathpix-markdown-it did not render LaTeX theorem environments (theorem, lemma, proof), which frustrated users pasting Mathpix OCR API output. After requests spanning two years, the maintainer announced theorem support with docs at doc/theorems.md in the repo. Update to a release that includes it and use the documented syntax.
2. Update mathpix-markdown-it to a release containing theorem support.
3. Expected: the environments typeset like they do in LaTeX documents. Success check: OCR output with theorems renders correctly.
4. - Theorem-like environments from Mathpix OCR output render as plain text.
5. - General LaTeX rendering is broken; that is a different issue.

• You are on a release predating the feature; update first.

6. The renderer simply had no handling for theorem-like environments until the maintainer added it.

When to use

You are seeing this: TL;DR: mathpix-markdown-it did not render LaTeX theorem environments (theorem, lemma, proof), which frustrated users pasting Mathpix OCR API output. Use this skill when you run into "mathpix-markdown-it: theorem environments not supported".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The renderer simply had no handling for theorem-like environments until the maintainer added it.

The thread asked: mathpix-markdown-it did not render LaTeX theorem environments like \begin{theorem}...\end{theorem}, \begin{lemma} or \begin{proof}. Users coming from the Mathpix OCR API output expected theorem and theorem-like environments to typeset like they do in LaTeX documents. After several users asked for it over two years, the maintainer announced theorem support with docs at doc/theorems.md in the repo.

The verified answer: Theorem support was added to mathpix-markdown-it; the maintainer announced it on the issue and pointed to the docs at doc/theorems.md in the repo. Update to a release that includes theorem support and use the documented syntax for theorem, lemma, proof and other theorem-like environments.

Thread: https://vectle.com/threads/thr_EICHvLZ6Z9RQDBmPs8gs-w