Lean 4 Proof Engineer for Formal Mathematics

Mercor; New York (NY); Remote; USD 28,000 - 55,000; Part time

Benefits offered by this job

W-2 employment via Cincinnatus LLC

Part-time hours: 20–40 h/w

Job summary

Cincinnatus LLC is placing Lean engineers and formal mathematicians at a leading AI lab to advance machine-checked mathematics in Lean 4. You will write and review lean proofs, translate informal math into formal statements, and assess model proofs for correctness.

This is a part-time role with 20–40 hours per week, offering W-2 employment through Cincinnatus. Ideal candidates have hands-on Lean 4 experience, familiarity with mathlib, and a strong proof-based mathematical background.

Qualifications

• Hands-on experience writing formal proofs in Lean 4.
• Comfort with mathlib and Lean 4 tactics.
• Strong background in proof-based mathematics or logic.
• Ability to turn a statement into a correct formal statement and proof.
• Engage reliably for at least 20 hours/week during weekdays.
• Clear written communication of proof strategies.

Responsibilities

• Write correct Lean 4 statements and proofs that compile against mathlib across algebra, analysis, number theory, combinatorics and logic.
• Formalize natural-language mathematics into precise formal statements.
• Review AI-generated Lean statements and proofs and provide precise feedback.
• Help define guidelines and rubrics for proof quality and mathlib conventions.
• Collaborate with Lean engineers and researchers to maintain standards.

Skills

Lean 4 proofs

mathlib familiarity

logic and math background

formalization ability

communication skills

time management

Education

Degree in mathematics or theoretical CS or logic

Tools

Lean 4

mathlib

Lean tactics

Job description

Cincinnatus LLC is placing Lean engineers and formal mathematicians at a leading AI lab to advance machine-checked mathematics in Lean 4. You will write and review lean proofs, translate informal math into formal statements, and assess model proofs for correctness.

This is a part-time role with 20–40 hours per week, offering W-2 employment through Cincinnatus. Ideal candidates have hands-on Lean 4 experience, familiarity with mathlib, and a strong proof-based mathematical background.