All open problems
Source labels openChecked July 26, 2026

Green's Open ProblemsNumber theory

Ben Green's Open Problem 62

Let pp be a large prime, and let AA be the set of all primes less than pp. Is every x{1,,p1}x \in \{1, \ldots, p-1\} congruent to some product a1a2a_1 a_2 where a1,a2Aa_1, a_2 \in A?

Mathematical statement

Let pp be a large prime, and let AA be the set of all primes less than pp. Is every x{1,,p1}x \in \{1, \ldots, p-1\} congruent to some product a1a2a_1 a_2 where a1,a2Aa_1, a_2 \in A?

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_62

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem green_62 :    answer(sorry)       ᶠ p in atTop, p.Prime         let A := (Finset.range p).filter Nat.Prime         x : , 1  x  x < p            a₁  A,  a₂  A, (x : ZMod p) = (a₁ * a₂ : ZMod p) := 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