Benchmark Almanac

FATE-X

Leanstral 1.5 34% leads since Jul 2026 Fading

Provers write Lean proofs for 100 algebra problems at or beyond PhD qualifying exam level, some beyond what Mathlib covers. The Lean compiler checks each proof.

Part of the FATE (Formal Algebra Theorem Evaluation) series with FATE-H. Seed-Prover 1.5 reports 33%.

In the authors’ words

Recent advances in large language models (LLMs) have demonstrated impressive capabilities in formal theorem proving, particularly on contest-based mathematical benchmarks like the IMO. However, these contests do not reflect the depth, breadth, and abstraction of modern mathematical research. To bridge this gap, we introduce FATE (Formal Algebra Theorem Evaluation), a new benchmark series in formal algebra designed to chart a course toward advanced mathematical reasoning. We present two new components, FATE-H and FATE-X, each with 100 problems in abstract and commutative algebra. The FATE series spans a difficulty spectrum from undergraduate exercises to problems exceeding PhD qualifying exams. Notably, FATE-X is the first formal benchmark to surpass both PhD-level exam difficulty and the coverage of the Mathlib library. Our evaluations of state-of-the-art LLM provers on this new benchmark reveal a stark performance gap compared to contest math: the best model achieves only 3% (pass@64) accuracy on FATE-H and 0% on FATE-X. Our two-stage evaluation reveals that models' natural-language reasoning is notably more accurate than their ability to formalize this reasoning. We systematically classify the common errors that arise during this formalization process. Furthermore, a comparative study shows that a specialized prover can exhibit less effective reflection than general-purpose models, reducing its accuracy at the natural-language stage. We believe FATE provides a robust and challenging benchmark that establishes essential checkpoints on the path toward research-level formal mathematical reasoning.

Abstract of FATE: A Formal Benchmark Series for Frontier Algebra of Multiple Difficulty Levels (arXiv:2511.02872, CC0)
Made by Jiang et al. (FATE team) Released Nov 2025 Formal proofs Last in a launch post Jul 2026 , dropped before it saturated Last model added Jul 2026
Level
Research frontier Researchers, on open problems or tasks that take days
Scored
Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
Answers
Written proof
2
Models scored in lab cards
2
Launch posts list it, from 2 labs
1
System card reports it, from 1 lab

Leanstral 1.5 leads with 34%

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

  1. 1 Leanstral 1.5 34%
  2. 2 Seed-Prover 1.5 33%
#ModelScoreSettingDateSource
1 Leanstral 1.5 34% Jul 2026 Model card
2 Seed-Prover 1.5 33% Dec 2025 Model card

2 models have held number one since its release in Nov 2025

Lab claims count from the day the card came out, independent runs from the model’s release.

ByteDance Seed Mistral AI
Lab claims Not tested since Jul 2026

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card Best so far
0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Leanstral 1.5 Seed-Prover 1.5 0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Leanstral 1.5

Labs headline it less often now, last in Jul 2026

Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.

ByteDance Seed
Mistral AI
DateLaunch postScoreAs the post writes it
2 Jul 2026 Leanstral 1.5 34 FATE-X 34%
19 Dec 2025 Seed-Prover 1.5 33 Fate-X

One system card reports it

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
2 Jul 2026 Leanstral 1.5 technical report 34 FATE-X pass@8, 27 at pass@2 (Table 2) Capabilities

More in Math

All 105 in Math
  • IMO-AnswerBench In use 400 olympiad problems with short verifiable answers, robustified against memorization. Scored by answer match. GLM-5.2 91%
  • AIME 2026 In use Models solve the 30 integer-answer problems from the 2026 AIME I and II math competitions. Scored by exact answer match. GPT-5.5 100%
  • HMMT 2026 In use Models solve the 33 final-answer problems from the February 2026 Harvard-MIT Mathematics Tournament. Scored by exact answer match. GPT-5.5 98.5%
  • MathArena (Apex, IMO, USAMO) In use Evaluates models on newly released math competitions after release. Final-answer or human/LLM-judged proof scores. Claude Opus 4.8 81.3%
  • PolyMath In use Models solve 9,000 parallel math problems in 18 languages across four difficulty levels, from school math to frontier math. Final answers are checked. Qwen3.7-Max 86.5%
  • USAMO 2026 In use Models write full proofs for the six problems of the 2026 USA Mathematical Olympiad. Judges grade each proof from 0 to 7 against rubrics. GPT-5.5 98.2%