You might be looking for:
- extensible equals inner: A proof that every extensible automorphism of a group is an inner automorphism. An automorphism of a group is termed extensible if for any group containing , there exists an automorphism of whose restriction to equals .
- extensible automorphisms problem: A discussion of extensibility of automorphisms and related questions.
- group property-conditionally extensible automorphism: The property of an automorphism being extensible with respect to a group property.
- variety-extensible automorphism: extensibility with respect to a variety of algebras.
Also check out quotient-pullbackable automorphism.