The violin string extends from x equals zero to x equals L, and we pluck the violin string.

弦从X轴指向原点,让x等于L，然后我们拉直那根弦。

麻省理工公开课 - 固态化学导论课程节选

Y You don't want to rename them L and R or X and Y right because you want to call them left and right.

你不想把它们重命名为L和R，或者X和,因为你想叫它们为left和。

哈佛公开课 - 计算机科学课程节选