Formal Mathematician

About the job

Mercor connects elite creative and technical talent with leading AI research labs. Headquartered in San Francisco, our investors include Benchmark, General Catalyst, Peter Thiel, Adam D'Angelo, Larry Summers, and Jack Dorsey.

Position: Lean Engineer, Formal Mathematics (Lean 4, Mathlib, Theorem Proving) Type:Contract Compensation:$90–$110/hour Location:Remote Commitment:20–40 hours/week

Role Responsibilities

• Write correct, idiomatic Lean 4 statements and proofs that compile against current mathlib. Cover areas such as algebra, analysis, number theory, combinatorics, and logic. • Formalize natural-language mathematics from competition problems and textbook results to research-level lemmas. Ensure the formal statement matches the original. • Review AI-generated Lean statements and proofs. Identify failures or incorrect proofs and provide clear, specific written feedback. • Help define guidelines and rubrics for proof quality, statement fidelity, and mathlib conventions. • Collaborate with other Lean engineers and the lab's researchers to maintain consistent standards and elevate quality.

Qualifications

Must-Have

• Hands-on experience writing formal proofs in Lean 4. Examples include mathlib contributions, a formalization project, or a Lean library or tool. • Comfort with mathlib and Lean 4 tactics. Ability to find and use the right lemmas. • Strong background in proof-based mathematics, theoretical computer science, or logic through a degree or research…