lower closure of concave-convex function

例句：

1. 1. The lower closure of the concave-convex function is a key concept in studying the shape of objects with complex surfaces.
   凹凸函数的下闭集是研究具有复杂表面形状的对象时的一个关键概念。
2. 2. In this study, we explore the lower closure of the concave-convex function to understandits impact on the stability of the system.
   在这项研究中，我们探索凹凸函数的下闭集，以理解其对系统稳定性的影响。
3. 3. The lower closure of the concave-convex function plays a crucial role in determining the boundary conditions for the solution of partial differential equations.
   凹凸函数的下闭集在确定偏微分方程解的边界条件下起着至关重要的作用。