The property of isotonicity of a continuous convex function on the positive cone is characterized via subdifferentials. This is used to illustrate a new generalization of the Hardy–Littlewood–Polya inequality of majorization to the case of functions of a vector variable.

中文翻译：

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从 Hahn-Banach 扩展定理到凸函数的等渗性和专业化理论

正锥上的连续凸函数的等渗性通过次微分表征。这用于说明 Hardy-Littlewood-Polya 不等式对向量变量函数情况的新推广。