code: package it.unibz.inf.ontop.model.vocabulary;
  
  import org.apache.commons.rdf.api.IRI;
  import org.apache.commons.rdf.api.RDF;
  import org.apache.commons.rdf.simple.SimpleRDF;
  
  public class OntopInternal {
  
      private static final String PREFIX = "urn:it:unibz:inf:ontop:internal:";
  
  
      public static final IRI NUMERIC;
      public static final IRI DATE_OR_DATETIME;
  
      /**
       * TODO: remove it!
       */
      public static final IRI UNSUPPORTED;
  
      public static final String PREFIX_XSD;
      public static final String PREFIX_RDF;
      public static final String PREFIX_RDFS;
      public static final String PREFIX_OWL;
      public static final String PREFIX_OBDA;
  
      static {
          RDF rdfFactory = new SimpleRDF();
  
          NUMERIC = rdfFactory.createIRI(PREFIX + "numeric");
          DATE_OR_DATETIME = rdfFactory.createIRI(PREFIX + "dateOrDateTime");
          UNSUPPORTED = rdfFactory.createIRI(PREFIX + "unsupported");
          PREFIX_XSD = "xsd:";
          PREFIX_RDF = "rdf:";
          PREFIX_RDFS = "rdfs:";
          PREFIX_OWL = "owl:";
          PREFIX_OBDA = "obda:";
  
      }
  }
  