Erdős problem 987
Clunie [Cl67] proved that there exists an infinite sequence on the unit circle with for all . Translating , the natural domain of is the half-open unit interval , matching the original [Er64b]/[Cl67] statement (any unit complex number is allowed, including , i.e. ).
Sources
FormalConjectures/ErdosProblems/
987.lean
Retained formal statement
Question 2 (parts.ii): Is it possible for ? Yes — there exists a sequence and a bound with eventually. A corollary of sqrt_log_upper_bound (which gives a bound) plus the asymptotic .
True ↔ ∃ x, ∃ (_ : ∀ (j : ℕ), x j ∈ Set.Ioo 0 1), ∃ b, (b =o[Filter.atTop] fun k => ↑k) ∧ ∀ᶠ (k : ℕ) in Filter.atTop, Erdos987.A x k ≤ ↑(b k)