Even though Generalization satisfies Structural, Interface, Behaviour properties. It is mathematically very strong, as it is Antisymmetric and Transitive.

Antisymmetric: employee is a person, but not all persons are employees. Mathematically all As’ are B, but all Bs’ not A.

Transitive: A=>B, B=>c then A=>c.

A. Salesman.

B. Employee.

C. Person.

Note: All the other relationships satisfy all the properties like Structural properties, Interface properties, Behaviour properties.