论文标题
正常衍生引理周围
Around the normal derivative lemma
论文作者
论文摘要
这项调查提供了对椭圆形偏微分方程定性理论之一的历史和艺术的描述，包括强大最大原理，边界点原理（正常导数引理）和相关主题。
This survey provides a description of the history and the state of the art of one of the most important fields in the qualitative theory of elliptic partial differential equations including the strong maximum principle, the boundary point principle (the normal derivative lemma) and related topics.
