摘要

Let G be a finite group and H a subgroup of G. Recall that H is said to be a TI-subgroup of G if H-g boolean AND H = 1 or H for each g is an element of G. In this note, we prove that if all non-nilpotent subgroups of a finite non-nilpotent group G are TI-subgroups, then G is soluble, and all non-nilpotent subgroups of G are normal.