recursive arithmetic

例句：

1. 1. The problem is that the solution to this problem is recursive.
   问题在于这个问题的解决方案是递归的。
2. 2. The algorithm is designed to be recursive, which means it can be broken down into smallerparts.
   这个算法被设计成递归的，这意味着它可以被分解成更小的部分。
3. 3. The recursive function calls itself again and again until it reaches a base case.
   这个递归函数一次又一次地调用自己，直到它达到一个基本情况。