Original sentence: In mathematics, a homothety (or homothecy or dilation) is a transformation of space which takes each line into a parallel line (in essence, a similarity that allows reflection in a single point, but otherwise preserves orientation)
Edited sentence: In mathematics, a homothety (or homothecy or non-rotating dilation) is a transformation of space which takes each line into a parallel line (in essence, a similarity that allows reflection in a single point, but otherwise preserves orientation)