[rdfweb-dev] Another relationships proposal

David Menendez zednenem at psualum.com
Fri Mar 19 19:06:11 UTC 2004

This is some noodling inspired by Ian Davis's work and Michael Bauser's

For kinship relations, I suggest this heirarchy of properties:


The sense of these are the same as in the Dublin Core, e.g., { A P B. }
is read as "B is a/the P of A" (note that N3 actually has a syntax form
that lets you write { B is P of A. }).

More specifically, the claim { A P B. } means "B is the P of A according
to A's cultural norms". This means that, for example, { A parent B }
does not imply { B child A }, because A and B may see things

Similarly, kin, ancestor, and descendent aren't transitive and kin and
sibling aren't symmetric.

For biological relationships (pedigree), we only need one property like
"biologicalParent". We can also define two classes:

    SexuallyConceivedBeing a owl:Class
    ; rdfs:subClassOf
      [ a owl:Restriction
      ; owl:onProperty biologialParent
      ; owl:cardinality "2"^^xsd:integer
    AsexuallyConceivedBeing a owl:Class
    ; rdfs:subClassOf
      [ a owl:Restriction
      ; owl:onProperty biologicalParent
      ; owl:cardinality "1"^^xsd:integer

Note that "biologicalParent" is entirely unconnected with "parent". It
may be useful to define convenience terms that are subproperties of
"biologicalParent" and "mother" or "father" for brevity, but I can't
think of any good names.

Marriage is more complicated, because it has a time aspect. People are
married after a certain date or during a certain period. I suggest
something like this:

    [ a Marriage
    ; between A, B
    ; during
      [ a Period
      ; began "2004-01-01"

"Period" takes one or both of "began" and "ended". (I also suggest using
it to indicate when a person was born and died, eg { A lived [ a Period;
began "1940"; ended "2004" ]. }.)

There's some disagreement about what exactly constitutes a marriage, so
we can either say that it's according to A and B's cultural norms, or we
can define subclasses corresponding to particular authorities (e.g.,
"Marriage according to the state of Massachusetts").

What do you think, sirs?
David Menendez <zednenem at psualum.com> <http://www.eyrie.org/~zednenem/>

More information about the foaf-dev mailing list