@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix owl11: <http://www.w3.org/2006/12/owl11#>.
@prefix : <http://bla>.
@prefix owlq: <http://bla>.

owl:DatatypeProperty a owl:Class.

# :foo owl11:disjointUnionOf (owl:DatatypeProperty owl:ObjectProperty).

owlq:VariableDefinition
      a       owl:Class ;
      rdfs:subClassOf
              [ a       owl:Restriction ;
                owl:allValuesFrom owl:DatatypeProperty ;
                owl:onProperty owlq:onProperty
              ] .

<http://test#prop>
      a       owl:ObjectProperty .

<http://test#vardef>
      a       owlq:VariableDefinition ;
      owlq:onProperty <http://test#prop>.