The HasProperty ReferenceTypeis a concrete ReferenceTypethat can be used directly. It is a subtype of the Aggregates ReferenceType.

The semantic is to identify the Propertiesof a Node. Propertiesare described in 4.4.2.

The SourceNodeof this ReferenceTypecan be of any NodeClass. The TargetNodeshall be a Variable. By using the HasProperty Reference, the Variableis defined as Property. Since Propertiesshall not have Properties, a Propertyshall never be the SourceNodeof a HasProperty Reference.