Don’t say anything about someone in email you would not be comfortable saying to them directly， because eventually they will read it.

追求数学真理是一项崇高的努力。

There are no objects whose existence is indubitable.

控制的艺术在于在鲁棒性和性能之间找到恰当的平衡。

唯一存在的限制是你脑海中的限制。