No president who performs his duties faithfully and conscientiously can have any leisure.

All of old. Nothing else ever. Ever tried. Ever failed. No matter. Try again. Fail again. Fail better.

The study of computational complexity is not just about solving problems, but also about understanding the limits of what can be computed.

质量的第一条规则是它必须被定义。

人心是复杂且常常矛盾的。