收缩核

Retract

用收缩核理论,证明了直线上有4种不同胚的收缩核.En(n≥2),存在可数多个不同胚的n维收缩核.

In this article, that E^1 has four no hememorphism retract is proved with retract theory. For E^n （n≥2）, there exists countable no hememorphim, n dimension retract.