SV: property inference rule

Hi Nikita
 
I remember something from my Relational Algebra; as well as 3-NF data
modelling.
 
Here is a good URL:
http://dimacs.rutgers.edu/Workshops/Security/program2/jim/node3.html
 
JJ
 

-----Oprindelig meddelelse-----
Fra: Nikita Ogievetsky [mailto:nogievet@cogx.com]
Sendt: 5. november 2001 18:33
Til: www-rdf-interest@w3.org
Emne: property inference rule


Does anybody know a way to express 
an inference rule that from:
 
<person rdf:ID="A">

    <hasBrother>

        <person>
            <hasDaughter rdf:resource="#C"/>

        </person>
    </hasBrother>
</person>
 
follows:
 
<person rdf:ID="A">

    <hasNiece rdf:resource="#C">
</person>
 
In other words:
 
{hasNiece} = {hasBrother X hasDaughter}
 
I had been pondering over this for some time
and could not find an answer neither myself nor by asking some other
people.
 
Thanks,
 
--Nikita.