Equation 17.10.365825ABE1D62B

\begin{equation} \sup _{\{ \varphi _1\neq -\infty \} }(\varphi _1-\varphi _0)= \adjustlimits \sup _{x\in X\setminus Z}\lim _{t\to 1-}\frac{\varphi _1(x)-\varphi _ t(x)}{1-t} =\sup _{\{ \varphi _1\neq -\infty \} }\frac{\varphi _1-\varphi _ s}{1-s}. \end{equation}