∀ {u : ℕ → ENNReal} {v : ℕ → ℕ} {a : EReal},
  Monotone u →
    Filter.Tendsto (fun n => ↑(v n) / ↑n) Filter.atTop (nhds a) →
      a ≠ 0 → a ≠ ⊤ → ExpGrowth.expGrowthInf (u ∘ v) = a * ExpGrowth.expGrowthInf u