SWI-Prolog -- rdf

Documentation
- Reference manual
- Packages
  - SWI-Prolog Semantic Web Library 3.0
    - Two RDF APIs
      - library(semweb/rdf11): The RDF database
        
        Query the RDF database
        
        rdf/3
        
        rdf/4
        
        rdf_has/3
        
        rdf_has/4
        
        rdf_reachable/3
        
        rdf_reachable/5
        
        {}/1
        
        rdf_where/1

Availability::- use_module(library(semweb/rdf11)).

[nondet]rdf_has(?S, +P, ?O)

[nondet]rdf_has(?S, +P, ?O, -RealP)

Similar to rdf/3 and rdf/4, but P matches all predicates that are defined as an rdfs:subPropertyOf of P. This predicate also recognises the predicate properties inverse_of and symmetric. See rdf_set_predicate/2.

Availability::- use_module(library(semweb/rdf_db)).

[nondet]rdf_has(?Subject, +Predicate, ?Object, -RealPredicate)

Same as rdf_has/3, but RealPredicate is unified to the actual predicate that makes this relation true. RealPredicate must be Predicate or an rdfs:subPropertyOf Predicate. If an inverse match is found, RealPredicate is the term inverse_of(Pred).