In OWL, distinctive URI resources may refer to the same individual of a particular class. To express two distinctive individuals are the same, the owl:sameAs property can be used.

Sometimes the "owl:sameAs" relationship is not explicited stated in an ontology, but it can be inferred from other OWL ontology constructs, for example, through the owl:FunctionalProperty and owl:InverseFunctionalProperty.

In this case section, we show how to infer distinctive individuals are the same individual through owl:FunctionProperty. In Case 6, we will show how similar inference can be done through the owl:InverseFunctionalProperty.

To demonstrate this inference support, we will show how F-OWL can deduce correct conclusions from a set of premises.

This example is based on the animals.owl ontology, and the ontology statements are expressed in N3.

Premises: Both John and Mark are individuals of the Person class. John is the father of Mark, defined by the animals:hasFather property. In addition

animals:John a animals:Person.
animals:Mark a animals:Person.
animals:JohnSmith a animals:Person.
animals:Mark animals:hasFather animals:John.
animals:Mark animals:hasFather animals:JohnSmith
animals:hasFather a owl:FunctionalProperty.

Conclusion: Person JohnSmith is the same individual as Person John.

animals:JohnSmith owl:sameAs animals:John.

The inference behind the above example is based on the fact animals:hasFather is a type of owl:FunctionalProperty, which uniquely identifies the range value of this object property.

To check if the conclusion can be correctly deduced by F-OWL, the following query can be used:

animals_JohnSmith [owl_sameAs -> animals_John].