%0 Journal Article %A C. J. Atkin %T Extension of smooth functions in infinite dimensions, I: unions of convex sets %J Studia Mathematica %D 2001 %P 201-226 %V 146 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4064/sm146-3-1/ %R 10.4064/sm146-3-1 %G en %F 10_4064_sm146_3_1