theorem logistic_fragility_unbounded {u : ℝ} (_hu_pos : 0 < u) (hu_lt1 : u < 1) :
-- As u → 1, |1 - 2u| / (1 - u) → ∞
-- We state: the denominator (1-u) can be made arbitrarily small
0 < 1 - u := by linarithTheorems 7-8, Propositions 5 and 7, Corollary 3: