如何将一个一维射影变换表示为两个对合的乘积

On One-dimensional Projective Transformation is the Product of Two Involution

本文讨论一维射影变换,主要结果是非对合的射影变换必是两个对合之积。

We mainly discuss one-dimensional projective fransformation,the main result is that non-involution of projective mapping is the product of twoinvolution.