Talk:Subdifferential

The article says

"The subdifferential of the support function of a convex set coincides with the set itself"

This seems to disagree with corollary 25.5.3 of Rockafellar's book. Or am I mistaken?

Could you please explain a little, what is the problem? I do not have that book on my table. I also note that compactness is required. --Boris Tsirelson (talk) 23:22, 7 October 2013 (CEST)