and the universally quantified conditional. Predication relationships express the notion that an individual entity is an example of a certain type (for example, John is a bachelor), while universally quantified conditionals express the notion that a type is a subtype of another type (for example, "A dog is a mammal", which means the same as "All dogs are mammals").

The "has-a" relationship is quite different: an elephant has a trunk; a trunk is a part, not a subtype of elephant. The study