FormalConjectures/ErdosProblems/868.lean
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5 declarations, 4 contain sorry, 0 declared as axioms
Erdős Problem 868
References:
- erdosproblems.com/868
- [LaLa26] Larsen and Larsen, Erdős problem 868 (2026)
Imports (1)
- def
Erdos868.ncard_add_reprline 40 sourcestandard axioms: Classical.choice, Quot.sound, propext what this means
Statement uses:
Set,NatProof uses:
Set.ncard,Fin,Set.ofPred,And,Monotone,LE.le,Set.range,Eq,Finset.sum,Finset.univ6 instances, coercions and auxiliary constants left out.
- theorem
Erdos868.erdos_868.parts.iLet $A$ be an additive basis of order $2$, let $f(n)$ denote the number of ways in which $n$ can be written as the sum of two elements from $A$ sorry line 50 sourceSource documentation
Let $A$ be an additive basis of order $2$, let $f(n)$ denote the number of ways in which $n$ can be written as the sum of two elements from $A$. If $f(n) \to \infty$ as $n \to \infty$, then must $A$ contain a minimal additive basis of order $2$?
Larsen and Larsen [LaLa26] answered this in the negative.
depends on sorry what this means
Statement uses:
Iff,False,Set,Nat,Set.IsAsymptoticAddBasisOfOrder,OfNat.ofNat,Filter.Tendsto, Erdos868.ncard_add_repr,Filter.atTop,Exists,And,LE.le,Membership.mem,Not,SDiff.sdiff,Singleton.singletonProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous14 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_868.parts.i : answer(False) ↔ ∀ (A : Set ℕ), A.IsAsymptoticAddBasisOfOrder 2 → atTop.Tendsto (fun n => ncard_add_repr A 2 n) atTop → ∃ B ⊆ A, B.IsAsymptoticAddBasisOfOrder 2 ∧ ∀ b ∈ B, ¬(B \ {b}).IsAsymptoticAddBasisOfOrder 2 := by …Mentions: Erdos868.ncard_add_repr
- theorem
Erdos868.erdos_868.parts.iiLet $A$ be an additive basis of order $2$, let $f(n)$ denote the number of ways in which $n$ can be written as the sum of two elements from $A$ sorry line 64 sourceSource documentation
Let $A$ be an additive basis of order $2$, let $f(n)$ denote the number of ways in which $n$ can be written as the sum of two elements from $A$. If $f(n) > \epsilon \log n$ for large $n$ and an arbitrary fixed $\epsilon > 0$, then must $A$ contain a minimal additive basis of order $2$?
Larsen and Larsen [LaLa26] constructed a counterexample with $f(n) > c \log n$ for all large $n$.
depends on sorry what this means
Statement uses:
Iff,False,Set,Nat,Real,GT.gt,OfNat.ofNat,Set.IsAsymptoticAddBasisOfOrder,Filter.Eventually,LT.lt,HMul.hMul,Real.log, Erdos868.ncard_add_repr,Filter.atTop,Exists,And,LE.le,Membership.mem,Not,SDiff.sdiffand 1 moreProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous28 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_868.parts.ii : answer(False) ↔ ∀ᵉ (A : Set ℕ) (ε > 0), A.IsAsymptoticAddBasisOfOrder 2 → (∀ᶠ (n : ℕ) in atTop, ε * Real.log n < ncard_add_repr A 2 n) → ∃ B ⊆ A, B.IsAsymptoticAddBasisOfOrder 2 ∧ ∀ b ∈ B, ¬(B \ {b}).IsAsymptoticAddBasisOfOrder 2 := by …Mentions: Erdos868.ncard_add_repr
- theorem
Erdos868.erdos_868.variants.fixed_εErdős and Nathanson proved that this is true if $f(n) > c \log n$ for all large $n$, for some fixed constant $c > (\log \frac{4}{3})^{-1}$ sorry line 73 sourceSource documentation
Erdős and Nathanson proved that this is true if $f(n) > c \log n$ for all large $n$, for some fixed constant $c > (\log \frac{4}{3})^{-1}$.
depends on sorry what this means
Statement uses:
Iff,True,Set,Nat,Real,GT.gt,Inv.inv,Real.log,HDiv.hDiv,OfNat.ofNat,Set.IsAsymptoticAddBasisOfOrder,Filter.Eventually,LT.lt,HMul.hMul, Erdos868.ncard_add_repr,Filter.atTop,Exists,And,LE.le,Membership.memand 3 moreProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous38 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_868.variants.fixed_ε : answer(True) ↔ ∀ᵉ (A : Set ℕ) (c > (Real.log (4 / 3))⁻¹), A.IsAsymptoticAddBasisOfOrder 2 → (∀ᶠ (n : ℕ) in atTop, c * Real.log n < ncard_add_repr A 2 n) → ∃ B ⊆ A, B.IsAsymptoticAddBasisOfOrder 2 ∧ ∀ b ∈ B, ¬(B \ {b}).IsAsymptoticAddBasisOfOrder 2 := by …Mentions: c, Erdos868.ncard_add_repr
- theorem
Erdos868.erdos_868.variants.Hartter_Nathansonsorry line 84 sourcedepends on sorry what this means
Statement uses:
Nat,LT.lt,OfNat.ofNat,Exists,Set,And,Set.IsAsymptoticAddBasisOfOrder,LE.le,Membership.mem,SDiff.sdiff,Singleton.singletonProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous14 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.