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的定义: 反
是欧
里得空间的对合等
,它的不动点集合是余维度为 1 的
子空间。