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Erdős problem 31

Given any infinite set A⊂NA\subset \mathbb{N} there is a set BB of density 00 such that A+BA+B contains all except finitely many integers.

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FormalConjectures/ErdosProblems/

31.lean

Retained formal statement1 of 1

Given any infinite set A⊂NA\subset \mathbb{N} there is a set BB of density 00 such that A+BA+B contains all except finitely many integers.

Conjectured by Erdős and Straus. Proved by Lorentz [Lo54].

FormalConjectures/ErdosProblems/31.leanErdos31.erdos_311 lineExact file
∀ (A : Set ℕ), A.Infinite → ∃ B, B.HasDensity 0 ∧ ∀ᶠ (n : ℕ) in Filter.atTop, n ∈ A + B
SolvedProof has a holelean4external proof

The proof uses `sorry`: part of the argument is written but not proved. Lean accepts the file; it does not accept the theorem.