What it is
AlphaProof is an AlphaZero-style agent that learns to write formal proofs in the Lean proof language, training by reinforcement learning over millions of automatically formalized problems. On the hardest problems it uses test-time RL, generating and learning from many related variants at inference to adapt to the specific problem. At the 2024 International Mathematical Olympiad it solved three of the five non-geometry problems, including the competition's hardest, and combined with AlphaGeometry 2 reached a score equal to a silver medallist.
Why it matters
Formal proofs are machine-checkable, so unlike most language-model math this reasoning is verifiably correct rather than merely plausible. A silver-medal-equivalent IMO score was the first medal-level result for an AI system, and this peer-reviewed work is the groundwork behind the gold-medal reasoning systems that followed in 2025.
Underlined numbers link to their source. Every metric and quoted figure is listed under Sources and data below.
Filed underformal proofs, reasoning, Lean, IMO, AlphaProof
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