Four equivalent conditions for a convex cone in a Euclidean space to be an Fσ-set are given. Our result answers in the negative a recent open problem posed by Tam [5], characterizes the barrier cone of a convex set, and also provides an alternative proof for the known characterizations of the inner aperture of a convex set as given by Brønsted [2] and Larman [3].
關聯:
Linear Algebra and Its Applications 90(C), pp.47-55
