Question

I’m trying to specify a constraint in my ontology:
Let’s say I have classes A, B and C and object properties “A hasB B” and “B hasC C”. I would like to specify constraint that every individual ‘a’ of A is indirectly related to at least one of C, i.e. exists b,c that “a hasB b” and “b hasC c”.

Is it possible to do this in OWL? If no, could you advice some technology that makes this sort of validation possible?

Answer 1

You can do the following (in Turtle syntax):

:A  rdfs:subClassOf  [
    a  owl:Restriction;
    owl:onProperty  :hasB;
    owl:someValuesFrom  [
        a  owl:Restriction;
        owl:onProperty  :hasC;
        owl:someValuesFrom  :C
    ]
] .

I’m not very literate in Manchester syntax, but it must be something like:

A  subClassOf  (hasB  some  ( hasC  some  C ))

Again, as others have pointed out, the existence of a an individual does not mean that such individual is mentioned anywhere in the data.