论文标题
愉快的练习
A pleasant exercise
论文作者
论文摘要
在1965年的AMS Boulder会议论文集中，Langlands指出了一个组合引理，其中涉及在有限的维度欧几里得矢量空间中附带有序分区的特征功能家族。兰兰兹没有任何迹象表明引理的证据，这被称为“令人愉快的运动”。由于我们没有在文献中找到证据，因此我们决定给出一个证据。我们认为，这对主题的历史具有一定的兴趣。
In the Proceedings of the AMS Boulder conference in 1965 Langlands states a combinatorial lemma involving families of characteristic functions attached to ordered partitions of an obtuse basis in a finite dimensional euclidean vector space. Langlands does not give any indication about the proof of the lemma which is said to be a "pleasant exercise". Since we did not find a proof in the literature we decided to give one. We believe it of some interest for the history of the subject.
