OAI/NumberTheory/EgyptianFractions/DivisorCounting.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

  1. lemma OAI.Problem337.finset_family_card_le_F line 12

    Source documentation

    A finite family of distinct denominator sets produces the same number of increasing one-expansions.

    lemma finset_family_card_le_F (family : Finset (Finset ℕ)) (k : ℕ)
        (hfinite : (OneExpansions k).Finite)
        (hfamily : ∀ s ∈ family, s.card = k ∧
          (∀ m ∈ s, 1 ≤ m) ∧ (∑ m ∈ s, (1 : ℚ) / m) = 1) :
        family.card ≤ F k := by
    …

    Mentions: OAI.Problem337.OneExpansions, OAI.Problem337.F

  2. lemma OAI.Problem337.countingDivisorSplitSet_positive line 41
  3. theorem OAI.Problem337.divisor_branching_lower_bound line 54

    Source documentation

    Branching over all noncolliding proper divisors of one denominator.

    theorem divisor_branching_lower_bound (s : Finset ℕ) (n : ℕ)
        (hn : n ∈ s) (hpos : ∀ m ∈ s, 1 ≤ m)
        (hsum : (∑ m ∈ s, (1 : ℚ) / m) = 1)
        (hfinite : (OneExpansions (s.card + 1)).Finite) :
        n.divisors.card - 1 - 2 * (s.card - 1) ≤ F (s.card + 1) := by
    …

    Mentions: OAI.Problem337.OneExpansions, OAI.Problem337.F