Geometric characterizations of the strict Hadamard differentiability of sets

Abderrahim Jourani, Moustapha Sène

Let $S$ be a closed subset of a Banach space $X$. Assuming that $S$ is epi-Lipschitzian at $\bar{x}$ in the boundary $ \bd S$ of $S$, we show that $S$ is strictly Hadamard differen…