A mathematician's work is never done; there are always more problems to solve.
El arte es la expresión de los más profundos pensamientos por el más sencillo de los medios.
当一个人开始长得像他的父亲时,他就知道自己正在变老。
如果你能想象它,并相信它,你就能实现它。
The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.