Question

The __________rule specifies that if an entity instance of the supertype is a member of only one subtype and cannot simultaneously be a member of any other subtype.

Answer 1

The Disjoint Rule specifies that an entity instance of a supertype can only belong to one subtype at a time.

Step-by-step explanation:

The rule that is being described in the question is known as the Disjoint Rule.

This rule is a property of inheritance in object-oriented programming, where an entity instance of a supertype can only belong to one subtype at a time.

It ensures that each entity instance is unambiguously associated with a single subtype.

For example, let's consider the supertype 'Animal' and its subtypes 'Cat' and 'Dog'.

According to the Disjoint Rule, if an entity instance is labeled as a 'Cat', it cannot simultaneously be labeled as a 'Dog' or any other subtype of 'Animal'.

The Disjoint Rule is important in maintaining the integrity and clarity of the inheritance hierarchy and preventing any confusion or overlapping of subtypes.