# No LLM Solved Yu Tsumura's 554th Problem

arXiv: https://arxiv.org/abs/2508.03685 · HTML: https://mlsanity.com/paper/2508.03685/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- First posted on arXiv 5 Aug 2025.

## Abstract (arXiv)

We show, contrary to the optimism about LLM's problem-solving abilities, fueled by the recent gold medals that were attained, that a problem exists -- Yu Tsumura's 554th problem -- that a) is within the scope of an IMO problem in terms of proof sophistication, b) is not a combinatorics problem which has caused issues for LLMs, c) requires fewer proof techniques than typical hard IMO problems, d) has a publicly available solution (likely in the training data of LLMs), and e) that cannot be readily solved by any existing off-the-shelf LLM (commercial or open-source).