theorem on addition of probabilities

例句：

1. 1.The theorem states that the sum of two numbers is always greater than their product.
   这个定理表明，两个数的和总是大于它们的积。
2. 2. The mathematician proved the theorem using a simple geometric construction.
   这位数学家使用一个简单的几何构造证明了这个定理。
3. 3. The theorem has been proven to be true in many cases, but it's still open to debate.
   这个定理在许多情况下已被证明是正确的，但它仍然有待争议。