gr:includes leaf node

@prefix gr: <http://purl.org/goodrelations/v1#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

gr:includes a owl:ObjectProperty ;
    rdfs:label "includes (0..1)"@en ;
    rdfs:comment """This object property is a shortcut for the original gr:includesObject property for the common case of having exactly one single gr:ProductOrService instance included in an Offering. 

When linking to an instance of gr:SomeItems or gr:Individual, it is equivalent to using a gr:TypeAndQuantityNode with gr:hasUnitOfMeasurement="C62"^^xsd:string and gr:amountOfThisGood="1.0"^^xsd:float for that good.

When linking to a gr:ProductOrServiceModel, it is equivalent to 
1. defining an blank node for a gr:SomeItems
2. linking that blank node via gr:hasMakeAndModel to the gr:ProductOrServiceModel, and
3. linking from the gr:Offering to that blank node using another blank node of type gr:TypeAndQuantityNode with gr:hasUnitOfMeasurement="C62"^^xsd:string and gr:amountOfThisGood="1.0"^^xsd:float for that good."""@en ;
    rdfs:domain gr:Offering ;
    rdfs:isDefinedBy <http://purl.org/goodrelations/v1> ;
    rdfs:range gr:ProductOrService .