文摘
In this paper, we first investigate an abstract subdifferential for which (using Ekeland’s variational principle) we can prove an analog of the Br?ndsted–Rockafellar property. We introduce the -r L –density-of a subset of the product of a Banach space with its dual. A closed r L –dense monotone set is maximally monotone, but we will also consider the case of nonmonotone closed r L –dense sets. As a special case of our results, we can prove Rockafellar’s result that the subdifferential of a proper convex lower semicontinuous function is maximally monotone. Keywords Abstract subdifferential Br?ndsted–Rockafellar property Multifunction Monotonicity Monotone polar r L –density