Lean 4 Proof Engineer - Mathematical Formalization

Lean 4 Proof Engineer - Mathematical Formalization

Posted Today by Alignerr

Negotiable
Undetermined
Remote
Manchester, England, United Kingdom

Summary: The Lean 4 Proof Engineer role focuses on translating informal mathematical proofs into machine-verifiable formalizations using Lean 4, bridging the gap between mathematics and computer science. This fully remote position is ideal for individuals with a strong mathematical background and formal verification expertise. The role involves analyzing proofs, constructing formalizations, and collaborating with researchers to enhance formal verification processes. Candidates should possess a Master's degree or higher in a relevant field and have hands-on experience with formal systems like Lean.

Key Responsibilities:

  • Translate informal mathematical proofs into Lean 4 (and related proof systems) with clarity, structure, and correctness.
  • Analyze generic and domain-specific proofs to identify gaps, hidden assumptions, and formalizable sub-structures.
  • Construct formalizations that test the limits of existing proof assistants.
  • Collaborate with researchers to design, refine, and evaluate strategies for improving formal verification pipelines.
  • Develop readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms.
  • Provide guidance on proof decomposition, lemma selection, and structuring techniques for formal models.
  • Investigate where automated provers break down and articulate precisely why.
  • Formalize classical proofs and compare machine-verifiable structures against textbook arguments.
  • Uncover deeper patterns or generalizations implicit in the original mathematics.

Key Skills:

  • Master's degree or higher in Mathematics, Logic, Theoretical Computer Science, or a closely related field.
  • Strong foundation in rigorous proof writing across areas such as algebra, analysis, topology, logic, or discrete mathematics.
  • Hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable formal systems.
  • Passionate about formal verification, proof assistants, and mechanized mathematics.
  • Able to translate informal arguments into clean, structured, machine-verifiable proofs.
  • Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools (nice to have).
  • Experience with large-scale formalization projects such as Mathlib (nice to have).
  • Strong communication skills for explaining formalization decisions, edge cases, and proof strategies.

Salary (Rate): £170.00/hr

City: Manchester

Country: United Kingdom

Working Arrangements: remote

IR35 Status: undetermined

Seniority Level: undetermined

Industry: IT

Detailed Description From Employer:

Lean 4 Proof Engineer — Mathematical Formalization

About The Role

What if your deep mathematical training could directly shape the future of AI — and push the boundaries of what machines can reason about? We're looking for mathematicians with formal verification expertise to translate rigorous human-written proofs into machine-verifiable Lean 4 formalizations. This role sits at the frontier of mathematics and computer science, working on problems that often lie beyond the reach of automated provers. You'll help map — and expand — what formal verification can express, capture, and automate. This is a fully remote, flexible contract role designed for mathematically mature problem-solvers who find beauty in precision and satisfaction in resolving what automated tools cannot yet bridge.

Organization: Alignerr

Type: Hourly Contract

Location: Remote

Commitment: 10–40 hours/week

What You'll Do

  • Translate informal mathematical proofs into Lean 4 (and related proof systems) with clarity, structure, and correctness
  • Analyze generic and domain-specific proofs to identify gaps, hidden assumptions, and formalizable sub-structures
  • Construct formalizations that test the limits of existing proof assistants — especially where current tools struggle or fail
  • Collaborate with researchers to design, refine, and evaluate strategies for improving formal verification pipelines
  • Develop readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms
  • Provide guidance on proof decomposition, lemma selection, and structuring techniques for formal models
  • Investigate where automated provers break down and articulate precisely why — complexity, missing lemmas, insufficient libraries, and beyond
  • Formalize classical proofs and compare machine-verifiable structures against textbook arguments
  • Uncover deeper patterns or generalizations implicit in the original mathematics

Who You Are

  • Hold a Master's degree or higher in Mathematics, Logic, Theoretical Computer Science, or a closely related field
  • Have a strong foundation in rigorous proof writing across areas such as algebra, analysis, topology, logic, or discrete mathematics
  • Have hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable formal systems — Lean 4 strongly preferred
  • Genuinely passionate about formal verification, proof assistants, and the future of mechanized mathematics
  • Able to translate informal arguments into clean, structured, machine-verifiable proofs

Nice to Have

  • Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools
  • Experience with large-scale formalization projects such as Mathlib
  • Exposure to theorem provers where automated reasoning frequently fails or requires manual scaffolding
  • Prior experience with data annotation, evaluation systems, or AI training workflows
  • Strong communication skills for explaining formalization decisions, edge cases, and proof strategies

Why Join Us

  • Work on genuinely frontier problems at the intersection of mathematics and AI
  • Collaborate with leading AI research teams pushing the state of the art in formal reasoning
  • Fully remote and flexible — structure your work around your life
  • Freelance autonomy with access to some of the most intellectually demanding problems in the field
  • Exposure to advanced LLMs and how formal mathematics is used to train and evaluate them
  • Potential for contract extension as new projects launch