What they built
TeXtinguisher, a fine-tuned Inkling-Small (SFT then GRPO on Tinker) that fixes LaTeX compile errors inside the editor, trained on 3,978 real error/fix pairs mined from TeX.StackExchange.
The result
85.2% of fixes compile vs 80.7% for GPT-5.5 and 82.4% for Claude Fable 5.1, at 0.95 s median vs 2.47-5.72 s; within six points of GPT-6 Astra at a fourteenth of its cost.
The number covers 647 held-out real single-file errors.
The layer: The learning loop
Reviewed corrections are kept as test cases and later used to train models.
- A log of every correction and who reviewed it
- Eval sets that grow from reviewed corrections
- New versions, then post-trained models, from that signal
Read the guide to the learning loop.