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Erdős problem 785

Let A,B⊆NA,B\subseteq \mathbb{N} be infinite sets such that A+BA+B contains all large integers. Let A(x)=∣A∩[1,x]∣A(x)=\lvert A\cap [1,x]\rvert and similarly for B(x)B(x). Is it true that if A(x)B(x)∼xA(x)B(x)\sim x then A(x)B(x)−x→∞A(x)B(x)-x\to \infty as x→∞x\to \infty?

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The source's own material, retained exactly.

10 retained statements36c6d0fef71a

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FormalConjectures/ErdosProblems/

785.lean

Retained formal statement3 of 10

Chen and Fang [ChFa15] proved A(x)B(x)−x≪A(x)cA(x)B(x)-x\ll A(x)^c cannot hold for any constant c>0c>0.

FormalConjectures/ErdosProblems/785.leanErdos785.erdos_785.variants.chen_fang8 linesExact file
∀ (A B : Set ℕ),  A.Infinite →    B.Infinite →      Erdos785.IsExactAdditiveComplement A B →        ∀ (c : ℝ),          0 < c →            ¬(fun x => ↑(Erdos785.counting A x) * ↑(Erdos785.counting B x) - ↑x) =O[Filter.atTop] fun x =>                ↑(Erdos785.counting A x) ^ c
SolvedStatement only, no proof