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的定义:
是欧几里得空
的对
等距同构,它的不动
是余维度为 1 的仿
子空
。