have l2 := (isLittleO_const_of_tendsto_atTop a ((tendsto_pow_atTop two_ne_zero).comp tendsto_log_atTop)).isBigO
n : ℕ
A a✝ b✝ c d u x y t σ' : ℝ
ψ Ψ : ℝ → ℂ
F G : ℂ → ℂ
f : ℕ → ℂ
𝕜 : Type
inst✝ : _root_.RCLike 𝕜
a b : ℝ
hb : 0 < b
l1 :
  (nabla fun n => n * (a + (n / b).log ^ 2)) = fun n =>
    a + ((n + 1) / b).log ^ 2 + n * (((n + 1) / b).log ^ 2 - (n / b).log ^ 2)
⊢ (nabla fun x => x * (a + (x / b).log ^ 2)) =O[atTop] fun x => x.log ^ 2
n : ℕ
A a✝ b✝ c d u x y t σ' : ℝ
ψ Ψ : ℝ → ℂ
F G : ℂ → ℂ
f : ℕ → ℂ
𝕜 : Type
inst✝ : _root_.RCLike 𝕜
a b : ℝ
hb : 0 < b
l1 :
  (nabla fun n => n * (a + (n / b).log ^ 2)) = fun n =>
    a + ((n + 1) / b).log ^ 2 + n * (((n + 1) / b).log ^ 2 - (n / b).log ^ 2)
l2 : (fun x => a) =O[atTop] ((fun x => x ^ 2) ∘ Real.log)
⊢ (nabla fun x => x * (a + (x / b).log ^ 2)) =O[atTop] fun x => x.log ^ 2