 a rectangle $\mathcal{R}$ containing $(a,b)$ such that $${\mathcal{C}}\cap \mathcal{R} \subset \left\{(a',b') \in   (0,+\infty)^0, \, h^0 (f_{(a,b)}, f_{(a',b')}) \leq \xi \right\}.$$ For all positive numbers $a', b'$, $$\begin{aligned} h^0 \left(f_{(a,b)}, f_{(a',b')}\right) \leq 0 h^0 \left(f_{(a,b)}, f_{(a,b')}\right) + 0 h^0 \left(f_{(a,b')}, f_{(a',b')} \right).\end{aligned}$$ We derive from Theorem 0.0 of [@Ibragimov0000] that $$\begin{aligned}  h^0 \left(f_{(a,b)}, f_{(a,b')} \right) \leq \