Some Applications of the Hahn-Banach Separation Theorem
arXiv:1712.10250
Abstract
We show that a single special separation theorem (namely, a consequence of the geometric form of the Hahn-Banach theorem) can be used to prove Farkas type theorems, existence theorems for numerical quadrature with positive coefficients, and detailed characterizations of best approximations from certain important cones in Hilbert space.
We dedicate this paper to our friend and colleague Professor Yair Censor on the occasion of his 75th birthday