Abstract: | ![]() In this paper, we deal with the following problem: given a real normed space E with topological dual E*, a closed convex set X E, two multifunctions :X 2X and , find such that We extend to the above problem a result established by Ricceri for the case (x) X, where in particular the multifunction is required only to satisfy the following very general assumption: each set (x) is nonempty, convex, and weakly-star compact, and for each y X–:X the set is compactly closed. Our result also gives a partial affirmative answer to a conjecture raised by Ricceri himself. |