On the Klee--Saint Raymond's Characterization of Convexity
用凸分析技术直接证明了Banach空间中一个凸性刻画定理，并在更弱条件下将其推广到局部凸空间。
Using techniques of convex analysis, we provide a direct proof of a recent characterization of convexity given in the setting of Banach spaces in [J. Saint Raymond, J. Nonlinear Convex Anal., 14 (2013), pp. 253--262]. Our results also extend this characterization to locally convex spaces under weaker conditions.