And all this is, is saying that when you take a mixed second derivative, it doesn't matter in which order you take the two derivatives.

麦克斯韦关系的本质是,当你考虑混合的二阶导数时，求导的顺序不影响最后的结果,现在，我们利用这些关系。

麻省理工公开课 - 热力学与动力学课程节选

Now all of this is a matter of record and I suppose needs to be paused over a little bit.

这些事情都是有记录的,我认为我们需要在上边停留一会儿。

耶鲁公开课 - 文学理论导论课程节选

How good it is to be alive is a matter of adding up all of the-- call it the contents of life.

活着有多美好取决于-,生活内容的总和。

耶鲁公开课 - 死亡课程节选