absolute complement of a set

例句：

1. 1. The number 5 is the perfect complement to the number 7 in this sequence.
   在这个序列中，数字5是数字7的完美补数。
2. 2. The two numbers add up to a perfect sum of 10, which is the sum of the first and second digits of the number 10.
   这两个数字加起来正好是10，这是数字10的首尾两位数之和。
3. 3. In mathematics, the perfect pair of primes is a pair of numbers that add up to a perfect square.
   在数学中，一个完美的质数对是指一对数字相加等于一个完全平方数。