证明是一种用于使他人相信数学陈述为真的工具。
A proof is a device for convincing someone else that a mathematical statement is true.
劳动是一切财富和一切文化的源泉。
The world is full of magic things, patiently waiting for our senses to grow sharper.
I never want to repeat myself—each project should have its own identity.
领导者必须有勇气为长期利益做出艰难的决定，即使这些决定在短期内不受欢迎。