Let G=N H be such that (|N|, |H|)=1, suppose that H is A-invariant and N is a Sylow tower group and all of Sylow subgroups of N are abelian.

• 设G = N / H且( N ； H ) = 1；假定H是A-不变的且N是一个Sylow塔群； N的Sylow-子群是交换的.