未经测试的程序是无法正常工作的。
Tennis is a mental game. Everyone is fit, everyone hits great forehands and backhands – it’s the upstairs that counts.
某个命题可以从某一组公理通过某一规则系统推导出来,这一事实本身并不使其为真。
A person is never happy except at the price of some ignorance.