Let $\epsilon,\delta>0$ be such that Theorem 8.3 holds. For $x\in B_{1}(p)$ and $\alpha\in\mathds{N}$ such that $T^{\delta}_{\alpha}(x)=0$, we denote by $\Gamma_{\alpha}(x)\subseteq O(4)$, the uniquely defined discrete subgroup arising from Theorem 8.3.