theorem on multiplication of probabilities

例句：

1. 1. The theorem states that thesum of all prime numbers is always aperfect square.
   这个定理表明所有质数之和总是一个完全平方数。
2. 2. Themathematician proved the theoremusing complex numbers.
   这位数学家使用复数证明了这个定理。
3. 3. The theorem has beenproven to be true for any positive integergreater than two.
   这个定理对于任何大于二的正整数都已被证明是正确的。