Kimina-Prover: reaching 92.2% on miniF2F with whole-proof RL and no search tree
The Lean 4 theorem proving line from Moonshot AI with Numina, deliberately contrarian: no prover feedback in training or inference, no Monte Carlo tree search, value function or process reward model (arXiv:2504.11354), so search is internalised into a single whole-proof generation, and a custom Formal Reasoning Pattern writes a natural-language draft before Lean code, recasting a sparse binary reward as a language problem. The base is Qwen2.5-72B with up to 32K context. Keep two generations apart: Preview (2025-04) reached 80.7% on miniF2F-test at pass@8192, the first public result above 80%; the 72B model (2025-07-10) reached 92.2% after adding TTRL search and error repair, the highest public reading then and the number on our card, while pass@1 under the same protocol is only 63.9%. Equal-budget pass@1/32/1024 of 63.9/84.0/87.7 leads the 671B DeepSeek-Prover-V2 (61.9/82.4/86.6) at all three budgets. Discounts: that table is Kimina's own and its DeepSeek rows are their reruns, the repo declares no licence, and miniF2F holds 244 problems now past 92%, so its power to separate frontier models is decaying. No third-party board exists here, so read the numbers as direction. Graded C (vendor-stated): nothing recomputed on a pinned commit.