本刊今年第3期发表了题为《巧用补集例一束》一文(记作文〔1〕),该文谈到的巧用补集思想进行解题,方法虽然很好,但如果不结合完全分划的思想一起使用,则容易出错。事实上,文〔1〕的例5与例6的答案就搞错了。下面谈谈这个问题。我们所说的完全分划是指:若集合M和集合列 In the 3rd issue of this year’s issue of the journal, the article titled “Creating a Supplementary Case with a Bundle” (in essay [1]) was published. This article discusses the use of complementary thoughts to solve problems. The method is very good, but if not It is easy to make mistakes by using together with the idea of ​​complete division. In fact, the answer to Example 5 and Example 6 in [1] is wrong. Let’s talk about this issue below. What we call full division refers to: if the set M and set column