The equivalence relation on a finite set is an important relation, which relates to the partition on the set.
有限集上等价关系是一个重要的关系，它同集合的划分有着密切的联系。
2
Generally speaking, there are few profound discussion and research on the partition and covering of finite set.
关于有限集合上的划分与覆盖，一般很少讨论和研究。
3
The equation is discretized by discontinuous Galerkin finite element method, that is approximating functions being discontinuous at the nodes of partition in time.