 \bar \alpha - 0$.\ 0.) Any two elements $\hat n', \hat n \in \mathcal{N}_{\bar \alpha -0} (\hat r)$ with $\hat n' \not= \hat n$ are $\mathcal{D}_{0 \bar \alpha}$-concatenated. This is because the number of $\hat n \in \mathcal{N}_{\bar \alpha - 0}(\hat r)$, which are $\mathcal{D}_{\bar \alpha}$-concatenated with $\hat n' \not= \hat n$, according to (\[0.0\]) is $$\label{0.00} \tau (\bar \alpha, \bar \alpha - 0) = \