differentiability of pointwise Lipschitz maps
Fréchet-valued pointwise Lipschitz maps
Let \(Y\) be a super reflexive Fréchet space. It is proved that every map \(f:{\mathbb{R}}\longrightarrow Y\) has a derivative at almost each point at which \(f\) is pointwise Lipschitz. This result is an extension of a Phillips' theorem (1940) for Lipschitz maps from \({\mathbb{R}}\) into a reflexive Banach space.
scientific article; zbMATH DE number 6077259