Namespace(rdf	= http://www.w3.org/1999/02/22-rdf-syntax-ns#)
Namespace(xsd	= http://www.w3.org/2001/XMLSchema#)
Namespace(rdfs	= http://www.w3.org/2000/01/rdf-schema#)
Namespace(owl	= http://www.w3.org/2002/07/owl#)
Namespace(a	= http://a.com/ontology#)

Ontology(

 Class(a:Book partial 
  a:Object)
 Class(a:Object partial)
 Class(a:Person partial)
 Class(a:Purchase partial 
  restriction(http://a.com/ontology#has_object allValuesFrom (a:Object))
  restriction(http://a.com/ontology#has_recipient allValuesFrom (a:Person))
  restriction(http://a.com/ontology#has_agent minCardinality(1))
  restriction(http://a.com/ontology#has_object minCardinality(1))
  restriction(http://a.com/ontology#has_purpose allValuesFrom (a:Purpose))
  restriction(http://a.com/ontology#has_agent allValuesFrom (a:Person)))
 Class(a:Purpose partial)

 ObjectProperty(http://a.com/ontology#has_agent
  range(a:Person))
 ObjectProperty(http://a.com/ontology#has_object
  range(a:Book))
 ObjectProperty(http://a.com/ontology#has_purpose
  range(a:Purpose))
 ObjectProperty(http://a.com/ontology#has_recipient
  range(a:Person))

 DatatypeProperty(http://a.com/ontology#has_amount
  range(xsd:float))

 Individual(http://a.com/ontology#Birthday_Gift
  type(a:Purpose))
 Individual(a:John
  type(a:Person))
 Individual(http://a.com/ontology#Lenny_The_Lion
  type(a:Book))
 Individual(a:Mary
  type(a:Person))
 Individual(http://a.com/ontology#Purchase_1
  type(a:Purchase)
  value(http://a.com/ontology#has_object http://a.com/ontology#Lenny_The_Lion)
  value(http://a.com/ontology#has_recipient a:Mary)
  value(http://a.com/ontology#has_purpose http://a.com/ontology#Birthday_Gift)
  value(http://a.com/ontology#has_agent a:John))

)