@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix : <foo://bla#>.
:ParentOf12YOChild  owl:equivalentClass [a owl:Restriction;
  owl:onProperty :hasChild; owl:someValuesFrom :12YOPerson].
:12YOPerson owl:equivalentClass [a owl:Restriction;
  owl:onProperty :age; owl:hasValue 12].
[ :name "John"; :age 35;  a :ParentOf12YOChild;
   :hasChild [:name "Alice"; :age 10], [:name "Bob"; :age 8]].
:age rdf:type owl:FunctionalProperty.
# :12YOPerson owl:equivalentClass owl:Nothing.

:TwoChildrenParent  owl:equivalentClass [a owl:Restriction;
  owl:onProperty :hasChild; owl:cardinality 2].
:ThreeChildrenParent  owl:equivalentClass [a owl:Restriction;
  owl:onProperty :hasChild; owl:minCardinality 3].