subPropertyOf

SubpropertyOf is a relation used in RDF Schema and OWL to connect two properties, indicating that the first is a more specific or narrower property than the second. If P is a subproperty of Q, then every occurrence of P is also an occurrence of Q. This supports property hierarchies and data interoperability by allowing reasoning with more general properties.

In RDF Schema, the predicate rdfs:subPropertyOf expresses this relationship. It is transitive: if P rdfs:subPropertyOf Q and Q rdfs:subPropertyOf R, then P rdfs:subPropertyOf R. Under standard RDFS entailment, any triple (s, P, o) implies (s, Q, o). Domain and range constraints are not automatically inherited by subproperties; you typically declare domain and range separately for each property.

In OWL, there are explicit forms for object and data properties: owl:SubObjectPropertyOf and owl:SubDataPropertyOf. These serve the same general purpose as subPropertyOf but are part of the more expressive OWL framework and interact with other OWL constructs, enabling richer reasoning about property characteristics, property chains, and other ontology constructs. The basic idea remains that a subproperty implies the corresponding superproperty in inferred data.

Practical use includes building hierarchical property schemes, enabling data integration, and allowing queries to match both specific and general properties. Cautions include potential cycles in property hierarchies and inconsistencies when combined with conflicting domain/range or other ontological axioms. SubpropertyOf is foundational for semantic interoperability in RDF(S) and OWL ontologies.