@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix : <foo://bla/names#>.

:child rdfs:domain :Parent; owl:inverseOf :parent.
:Person rdfs:subClassOf
 [a owl:Restriction; owl:onProperty :parent; owl:cardinality 2].
:Parent owl:equivalentClass
 [a owl:Restriction; owl:onProperty :child; owl:minCardinality 1].

### add a person whose parent isn't a Parent:
:foo1 a :Person; :parent :foo2.
:foo2 a [owl:complementOf :Parent ].