group of outer automorphism

例句：

1. 1.The group of outer automorphism is crucial for the stability of the system.
   外群的自同构群对于系统的稳定性至关重要。
2. 2.The study of outer automorphism groups has led to many new insights into the nature of symmetry.
   研究外群自同构群已经为对称性的本性带来了许多新的见解。
3. 3. In this paper, we will discuss some properties of the group of outer automorphisms.
   在本文中，我们将讨论外群自同构群的一些性质。