The beauty of a mathematical proof lies in its simplicity and inevitability.
Let him be without suspicion who has done no wrong.
出自晋·葛洪《抱朴子·博喻》。用美玉做成的船和桨,不能用于水上航行;用黄金做弓,玉石做弦,仍没有射箭的功能。(笔杆子 rendoc.com)