Benchmark Almanac

IMO-LeanProofBench

LEAP (Agentic Prover) 70% tops its leaderboard Gemini 3.1 Pro 11.6% leads the models we track
Not in model cards

Models write Lean 4 proofs for the 60 IMO-ProofBench problems, formalized by hand and checked by Lean experts. The Lean compiler verifies each proof.

Introduced with the LEAP paper. One-shot Gemini 3.1 Pro solved 11.6 percent and the LEAP agent 70 percent. The August 2026 v2 file fixed wrong formalizations for Mathlib 4.27.0.

Released
June 2026
Kind
Formal proofs
Level
Competition
Scored
Checked automatically
Answers
Written proof
Tasks
All public
Strongest model tested
Gemini 3.1 Pro #39 on the capability index
Last model added
February 2026
Scores refreshed
November 12th, 2026
2
Entries on its own leaderboard, 1 model we track

LEAP (Agentic Prover) tops the leaderboard with 70%

Best score per entry from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best. Names in gray aren't in our model list: fine-tunes, agent systems, products and older models. They don't count toward leaders. The best model we track is Gemini 3.1 Pro, at 11.6%.

  1. 70.0 LEAP (Agentic Prover)
  2. 11.6 Gemini 3.1 Pro
  1. 1 LEAP (Agentic Prover) 70%
  2. 2 Gemini 3.1 Pro one-shot 11.6%

Source: Official IMO-LeanProofBench leaderboard

#EntryScoreSettingDateSource
1 LEAP (Agentic Prover) 70% LEAP Official leaderboard
2 Gemini 3.1 Pro 11.6% one-shot Feb 2026 Official leaderboard

Scores over time

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

On the benchmark’s own leaderboard
0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Gemini 3.1 Pro 0% 20% 40% 60% 80% 100% 2026 Near the ceiling (85%) Gemini 3.1 Pro

Source: Official IMO-LeanProofBench leaderboard

No lab model card reports it yet

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.

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  • 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%
  • 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%
  • 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%
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