# Example: A Company is running 'Direct Marketing' campaigns for
# a purpose (CampaignA), within which it runs another special
# campaign (CampaignB). This may evolve into another campaign C.
# RDFS+SKOS modelling
dpv:Marketing a rdfs:Class, dpv:Purpose .
dpv:DirectMarketing a dpv:Purpose; skos:broader dpv:Marketing .
ex:CampaignA a dpv:Purpose; skos:broader dpv:DirectMarketing .
ex:CampaignB a dpv:Purpose; skos:broader ex:CampaignA .
# valid statements as all objects are instances of dpv:Purpose
ex:Documentation a dpv:Process; dpv:hasPurpose dpv:DirectMarketing .

# OWL2 modelling
dpv:Marketing a owl:Class; rdfs:subClassOf dpv:Purpose .
dpv:DirectMarketing a owl:Class; rdfs:subClassOf dpv:Marketing .
ex:CampaignA a dpv:DirectMarketing .
# problem: instance of instance
ex:CampaignB a ex:CampaignA .
# solution: change CampaignA to subclass 
ex:CampaignA rdfs:subClassOf dpv:DirectMarketing .
# problem: DirectMarketing is not an instance of dpv:Purpose
ex:Documentation a dpv:Process; dpv:hasPurpose dpv:DirectMarketing .
# solution: blank nodes, but not a good solution
ex:Documentation a dpv:Process; dpv:hasPurpose [ a dpv:DirectMarketing ] .
# solution: use the instances rather than the class
ex:Documentation a dpv:Process; dpv:hasPurpose ex:CampaignA .
# problem: does not reflect the terminology used by Company/Law