Hi, I am wondering what the difference between 'generalized gradient' and 'subgradient' of a (potentially non-differentiable) convex function 'f' is.

The generalized gradient I am interested in is meant in the sense of the paper http://www.is.tuebingen.mpg.de/fileadmin/user_upload/files/publications/ICML2010-Kim_6519[0].pdf (see page 3, footnote 2).

many thx for any help.

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for convex functions, the set $\partial_G\phi$ there boils down to the standard subdifferential $\partial \phi$..... –  Suvrit Jan 13 '13 at 17:41