We discuss how meaningful is the concept of an epimaximal Ӿ -subgroup dual to the concept of a submaximal Ӿ -subgroup introduced by H. Wielandt. Also a result of Wielandt is refined which characterizes the behavior of maximal Ӿ -subgroups under homomorphisms.

中文翻译：

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次极大值和极值极值 Ӿ -子群

我们讨论与 H. Wielandt 引入的次极大 Ӿ - 子群的概念对偶的极值 Ӿ - 子群的概念有何意义。Wielandt 的结果也得到了改进，它表征了最大 Ӿ -子群在同态下的行为。