Permutable 2-subnormal subgroup

Definition
A subgroup of a group is termed a permutable 2-subnormal subgroup if it is both a permutable subgroup and a 2-subnormal subgroup.

Stronger properties

 * Weaker than::Normal subgroup
 * Weaker than::Subgroup contained in the Baer norm

Weaker properties

 * Stronger than::Permutable subnormal subgroup
 * Stronger than::Permutable subgroup
 * Stronger than::2-subnormal subgroup
 * Stronger than::Subnormal subgroup
 * Stronger than::Conjugate-permutable subgroup