%0 Journal Article
%T Smooth extensions of functions on separable Banach spaces
%A D. Azagra
%A R. Fry
%A L. Keener
%J Mathematics
%D 2009
%I arXiv
%X Let $X$ be a Banach space with a separable dual $X^{*}$. Let $Y\subset X$ be a closed subspace, and $f:Y\to\mathbb{R}$ a $C^{1}$-smooth function. Then we show there is a $C^{1}$ extension of $f$ to $X$.
%U http://arxiv.org/abs/0906.2989v2