A Proof of Lie's Theorem的用法和样例：
- I took this to be a proof of his lack of principle.
- Wiglaf was a proof of concept, not a final product.
- A lapse in memory: is it a proof of non-existence?
- The blood on his shoes was a proof of his guilt.
- Ask students to demonstrate a proof of the Pythagorean Theorem.
- We have constructed a proof of the theorum.