Equation 7.9.3B8751A529320

\begin{equation} \| H_{f,\varphi }-H_{g,\chi }\| _{L^\infty (B)} \le \| \varphi -\chi \| _{L^\infty (\partial B)} +R^2\| f^{1/n}-g^{1/n}\| _{L^\infty (B)}. \end{equation}