Sperner's lemma concerns the decomposition of a simplex into smaller simplices.

斯波纳引理涉及到把一个单纯形分解为较小的单纯形的问题。

Let G be a graph and let V(G) be the vertex set of G. Define the neighborhood complex N(G) as the simplicial complex whose simplices are those subsets of V(G) which have a common neighbor.

一个图G的邻域复形是以G的顶点为顶点，以G的具有公共邻接顶点的顶点子集为单形的抽象复形。