+ <rdfs:isDefinedBy rdf:resource = "&hns;" />
+</rdf:Property>
+
+<rdf:Property rdf:ID="occurrence">
+ <rdfs:comment>URI of an object</rdfs:comment>
+ <rdfs:domain rdf:resource="#Occurrence"/>
+ <rdfs:range rdf:resource="&hthns;HelmURI"/>
+ <rdfs:isDefinedBy rdf:resource = "&hns;" />
+</rdf:Property>
+
+<rdf:Property rdf:ID="position">
+ <rdfs:comment>Position of an occurrence</rdfs:comment>
+ <rdfs:domain rdf:resource="#Occurrence"/>
+ <rdfs:range rdf:resource="#Position"/>
+ <rdfs:isDefinedBy rdf:resource = "&hns;" />