Group-closed automorphism property
From Groupprops
Template:Automorphism metaproperty
Definition
An automorphism property is termed group-closed if the set of automorphisms of a group which satisfy the given property form a subgroup of its automorphism group. In fact, if they do form a subgroup, that subgroup must be a normal subgroup (it need not, however, always be a characteristic subgroup of the automorphism group).
