Discussion Count

The discussion count of $a \in A$ is the sequence $\mathsf{D}^F(a) = \langle -|\mathsf{P}^F_1(a)|, |\mathsf{P}^F_2(a)|, -|\mathsf{P}^F_3(a)|, \ldots \rangle$, where $\mathsf{P}^F_i(a)$ is the set of attack paths $(b_i, \ldots, b_1, a)$ of length $i$ ending in $a$.