Erdős problem 50
Schoenberg [Sch38] proved that the asymptotic distribution function of exists. That is, for any , the proportion of integers satisfying approaches a limit as . This limit function is the cumulative distribution function of the values of .
Sources
FormalConjectures/ErdosProblems/
50.lean
Retained formal statement
Let be the asymptotic distribution function of , so that for each , is the natural density of . Is it true that there is no such that the derivative exists and is positive?
sorry ↔ ∀ (f : ℝ → ℝ), Erdos50.IsDistributionOfPhiRatio f → ¬∃ x ∈ Set.Icc 0 1, ∃ y > 0, HasDerivWithinAt f y (Set.Icc 0 1) xOpenStatement only, no proof