Equation 20.3.471D55891047AA

\begin{equation} \begin{gathered} \nu (w_ a\circ \sigma ,F)=\tau _{B,U}(F) \quad \hbox{for every divisor }F\hbox{ over }B,\\ (a/2)^ d\leq \int _ B\mathrm{MA}_{a\kappa }(w_ a)\leq a^ d. \end{gathered} \end{equation}