Unipotent automorphism-invariant subgroup

Definition
A subgroup of a group is termed a unipotent automorphism-invariant subgroup if it is invariant under all unipotent automorphisms of the whole group.

Formalisms
The property of being unipotent automorphism-invariant can be expressed as the :

Unipotent automorphism $$\to$$ Function

It is in fact an endo-invariance property:

Unipotent automorphism $$\to$$ Endomorphism

Because the inverse of a unipotent automorphism is unipotent, it can in fact be expressed as an auto-invariance property:

Unipotent automorphism $$\to$$ Automorphism

Finally, since the property of being unipotent is preserved under restricting the action to a subgroup, it can be expressed as a :

Unipotent automorphism $$\to$$ Unipotent automorphism

Stronger properties

 * Weaker than::Characteristic subgroup