Formula_10235

\[\Delta(\mathscr{S})= \begin{cases}1, & \text { если } \mathscr{S}=\varnothing, \\ \prod_{i} \Delta\left(\gamma^{i}\right), \text { если } \mathscr{\Theta}=\left\{\gamma^{1}, \ldots, \gamma^{i}, \ldots\right\},\end{cases}\]