CombiBench: 100 Combinatorial Math Problems in Lean 4 Formal Language

CombiBench consists of 100 manually produced combinatorial mathematics problems encoded in the Lean 4 formal language. Developed by AI-MO and updated in July 2025, it serves as a specialized benchmark for assessing the reasoning capabilities of automated theorem proving systems.

Use Cases

• Evaluating automated theorem proving systems using the Lean 4 problem statements
• Fine-tuning language models to generate formal proofs for combinatorial challenges
• Benchmarking mathematical reasoning by solving problems of varying difficulty levels

Strengths

• 100 manually produced records
• Lean 4 formal language encoding
• Expert-curated difficulty levels

Limitations

• Small sample size of 100 problems
• Domain-specific focus limited to combinatorics
• Requires Lean 4 environment for execution

Provenance

Source

AI-MO

Collection Method

manual annotation

Freshness

Last updated July 2025.