nulhomotopy

例句：

1. 1. The mathematical model is a good example of nulhomotopy.
   这个数学模型是一个很好的无自我同构体的例子。
2. 2.In the field of computer science, nulhomotopy plays an important role.
   在计算机科学领域，无自我同构体起着重要的作用。
3. 3.The concept of nulhomotopy has been studied for decades.
   无自我同构体的概念已经研究了几十年。