FormalConjectures/ErdosProblems/306.lean
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2 declarations, 2 contain sorry, 0 declared as axioms
Erdős Problem 306
References:
- erdosproblems.com/306
- [Ta26] Tang, Yuren, A Lean 4 formalisation of Erdős Problem 306, which derives the statement below from two results of Rosser and Schoenfeld, Approximate formulas for some functions of prime numbers, Illinois J. Math. 6 (1962), 64-94, declared there as axioms
Imports (1)
- theorem
Erdos306.erdos_306Let $\frac a b\in \mathbb{Q}_{>0}$ with $b$ squarefree sorry line 44 sourceSource documentation
Let $\frac a b\in \mathbb{Q}_{>0}$ with $b$ squarefree. Are there integers $1 < n_1 < \dots < n_k$, each the product of two distinct primes, such that $\frac{a}{b}=\frac{1}{n_1}+\cdots+\frac{1}{n_k}$?
depends on sorry what this means
Statement uses:
Iff,True,Rat,LT.lt,OfNat.ofNat,Squarefree,Nat,Rat.den,Exists,Fin,HAdd.hAdd,And,Eq,StrictMono,Membership.mem,Finset,Finset.Icc,Fin.last,ArithmeticFunction,ArithmeticFunction.cardDistinctFactorsand 3 moreProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous48 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_306 : answer(sorry) ↔ ∀ (q : ℚ), 0 < q → Squarefree q.den → ∃ k : ℕ, ∃ (n : Fin (k + 1) → ℕ), n 0 = 1 ∧ StrictMono n ∧ (∀ i ∈ Finset.Icc 1 (Fin.last k), ω (n i) = 2 ∧ Ω (n i) = 2) ∧ q = ∑ i ∈ Finset.Icc 1 (Fin.last k), (1 : ℚ) / (n i) := by … - theorem
Erdos306.erdos_306.variants.integer_three_primesEvery positive integer can be expressed as an Egyptian fraction where each denominator is the product of three distinct primes sorry line 55 sourceSource documentation
Every positive integer can be expressed as an Egyptian fraction where each denominator is the product of three distinct primes.
depends on sorry what this means
Statement uses:
Nat,LT.lt,OfNat.ofNat,Exists,And,GT.gt,Fin,HAdd.hAdd,Eq,Fin.mk,Membership.mem,Finset,Finset.Icc,Fin.last,ArithmeticFunction,ArithmeticFunction.cardDistinctFactors,ArithmeticFunction.cardFactors,Rat,Finset.sum,HDiv.hDivProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous48 instances, coercions and auxiliary constants left out.
Tactic trace: 3 steps
Open to load the checked before-and-after goal states.
theorem erdos_306.variants.integer_three_primes (m : ℕ) (h : 0 < m) : ∃ k > (0 : ℕ), ∃ (n : Fin (k + 1) → ℕ), n 0 = 1 ∧ ∀ i, (hik : i < k) → n ⟨i, by omega⟩ < n ⟨(i + 1), by omega⟩ ∧ (∀ i ∈ Finset.Icc 1 (Fin.last k), ω (n i) = 3 ∧ Ω (n i) = 3) ∧ m = ∑ i ∈ Finset.Icc 1 (Fin.last k), (1 : ℚ) / (n i) := by …