Mistral launches Leanstral 1.5 – cutting the cost of formal proofs
Mistral AI has released Leanstral 1.5, a new AI model for formal mathematical proofs that drastically reduces costs and sets new performance records.
What happened?
Mistral AI has launched Leanstral 1.5, a specialised AI model for formal proofs in the Lean 4 programming language. The model has a total of 119 billion parameters, of which 65 billion are active. On the PutnamBench benchmark, Leanstral 1.5 solves a total of 587 out of 672 problems at an average cost of approximately USD 4 per problem.
Key facts
| Modellnamn | Leanstral 1.5 |
|---|---|
| Aktiva parametrar | 65 miljarder (119 miljarder totalt) |
| Kostnad per problem | Cirka 4 USD |
| PutnamBench-resultat | 587 av 672 problem lösta |
| Licens | Apache-2.0 |
Why it matters
The launch marks a significant reduction in the costs associated with formal proofs, which previously could amount to tens or hundreds of dollars per problem. Furthermore, the model reached new record levels on abstract algebra benchmarks, achieving 87% on FATE-H and 34% on FATE-X.
Who is affected?
The model is aimed primarily at researchers in mathematics and computer science, as well as developers working with formal verification and software security.
Impact on the EU
The model has been released under the Apache-2.0 open-source licence with free API access, making it immediately available to researchers and developers within the EU without restrictions.
What else you should know
In addition to mathematical proofs, Mistral AI demonstrated the model's practical utility by applying it to code verification, which led to the discovery of 11 genuine bugs across 57 open-source Rust codebases.
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