Subnormal-permutable subgroup

Symbol-free definition
A subgroup of a group is termed subnormal-permutable if it permutes with every defining ingredient::subnormal subgroup of the group.

Stronger properties

 * Weaker than::Subgroup contained in the Wielandt subgroup
 * Weaker than::Subnormal-permutable subnormal subgroup
 * Weaker than::Normal subgroup
 * Weaker than::Permutable subgroup
 * Weaker than::Perfect subnormal subgroup