仿射的

These observations allow one to formalize the definition of reflection: a reflection is an involutive isometry of an Euclidean space whose set of fixed points is an affine subspace of codimension 1.

这些观察允许我们形式化反射定义: 反射是欧几里得空间对等距同，不动点集是余维度 1 射子空间。