Automorphism-invariant Euclidean norm

Definition
A norm on a commutative unital ring is termed an automorphism-invariant Euclidean norm or a characteristic Euclidean norm if it satisfies the following two conditions:


 * It is an automorphism-invariant norm: The image of an element of the ring under an automorphism has the same norm as the element.
 * It is a Euclidean norm.

Weaker properties

 * Stronger than::Automorphism-invariant Dedekind-Hasse norm