All open problems
Source labels openChecked July 26, 2026

Green's Open ProblemsCombinatorics

Green's Open Problem 52

Suppose that AF2nA \subset \mathbb{F}_2^n is a set with an additive complement of size KK. Does 2A2A contain a coset of codimension OK(1)O_K(1)?

Mathematical statement

Suppose that AF2nA \subset \mathbb{F}_2^n is a set with an additive complement of size KK. Does 2A2A contain a coset of codimension OK(1)O_K(1)?

Statement source: Green's Open Problems statement material

Statement terms: Source-specific

Source-specific terms. Therefore does not assert reuse rights beyond attributed display.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

green_52

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem green_52 :    answer(sorry)   (c :   ),  (n K : ) (A : Set (𝔽₂ n)) (S : Finset (𝔽₂ n)),      S.card = K  A + (S : Set (𝔽₂ n)) = Set.univ        (V : AffineSubspace (ZMod 2) (𝔽₂ n)), (V : Set (𝔽₂ n))  A + A         n  Module.finrank (ZMod 2) V.direction + c K := by  sorry
Statement source
Formal Conjectures
Lean version
v4.27.0
Placeholder
Present; no proof artifact
Source evidence
Pinned source index
Fidelity review
Community formulation

References