. The extremal function $\Psi^{*}_{U}\in{\cal P}_{\gamma}\cap L^{\infty}(X)$ satisfies $\Psi^{*}_{U}\geq 0$ over $X$, $\Psi^{*}_{U}\equiv 0$ over $U$ and $\gamma^{n}_{\Psi^{*}_{U}}=0$ over $X\smallsetminus\overline{U}$.