Misc. bug: Svelte WebUI Improve default LaTeX rendering

[ServeurpersoCom]

Name and Version

Last master (scripted auto git rebase) on a dedicated LLM server @home

Operating systems

All

Which llama.cpp modules do you know to be affected?

Svelte WebUI

Command line

All

Problem description & steps to reproduce

• Ask model to write some maths

/!\ IMPORTANT : Don't ask more, no system prompt, don't say "latex" or "code block".

I plan to improve the Markdown/LaTeX rendering pipeline to better match the default LaTeX output style used by most language models.

After testing several models (including GPT-OSS 120B), it appears that the majority follow the same formatting preference.

- Inline LaTeX for short equations inside text
\[ x + 5 = 10 \]

- Centered block LaTeX for standalone equations
\[
e^{i\pi} + 1 = 0
\]

Currently, the WebUI displays these as raw text
I noticed that it was the same before my refactors of the rendering chain, this issue is present since the Svelte WebUI migration, and it's okay in the legacy React (including in the forks).

First Bad Commit

React to Svelte

Relevant log output

[ServeurpersoCom]

Enable this :

Ask for some maths and no more.
Inline :

Centered :

[ServeurpersoCom]

Some LLMs write this by default, and it works.

Target Markdown format (rendering disabled) :

Result (rendering enabled) :

[ServeurpersoCom]

OK, solved: I added a remark plugin stage in the rendering pipeline to rewrite MathJax-style bracket delimiters into KaTeX-friendly dollar math!

Svelte + remark architecture is awesome!

KaTeX != MathJax: most LLMs use MathJax-style syntax by default -> it was broken before and now it’s fixed with this PR, and sometimes they output plain LaTeX inside Markdown, which always worked and made the issue confusing at first (that’s probably why everyone forgot about it)!

KaTeX-vs-MathJax.mp4