在代数中，两个量的相等性通过方程来表达。

The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.

Success is not final, failure is not fatal: It is the courage to continue that counts.

白天鹅不每天沐浴，也是洁白的；黑乌鸦不每天暴晒，也是黑的。

要获得真正的成功，你需要先了解哪些事情会导致失败，然后避免它们。

定义就是限制。