Seminormal subgroup

In mathematics, in the field of group theory, a subgroup A of a group G is termed seminormal if there is a subgroup B such that A B = G , and for any proper subgroup C of B , A C is a proper subgroup of G .

This definition of seminormal subgroups is due to Xiang Ying Su.

Every normal subgroup is seminormal. For finite groups, every quasinormal subgroup is seminormal.