RE: "Transitive over" properties

Minsu wrote:
> To me, Jos De_Roo's solution looks like a nice one
> illustrating the complementary roles of rules and ontology.
>
> But, it'd be more concise to me if there were two rules;
> one for expressing the semantics of owl:TransitiveProperty,
> and another for relating 'worksFor' and 'consistsOf'. Here's
> my take:
>
> [Ontology Part]
> :consistsOf a owl:TransitiveProperty.
> :aCompany :consistsOf :rAndD.
> :rAndD :consistsOf :gSw.
> :gSw :consistsOf :gSwBe.
> :mk :worksFor :gSwBe.
>
> [Rule Part 1: OWL Semantics]
> if owl:TransitiveProperty(?p) and ?p(?x,?y) and ?p(?y,?z)
> then ?p(?x,?z);

Right and in N3 [1][2] we write that as
{?P a owl:TransitiveProperty. ?X ?P ?Y. ?Y ?P ?Z} => {?X ?P ?Z}.

not sure however if :consistsOf was intended to be transitive ??


> [Rule Part 2: TransitiveOver Property]
> if worksFor(?a,?b) and consistsOf(?b,?c)
> then worksFor(?a,?c);

I guess it's consistsOf(?c,?b) ??
but indeed and I tried to catch that in
{?P :transitiveOver ?Q. ?c ?Q ?b. ?a ?P ?b} => {?a ?P ?c}.
which takes care of the ?P closure

> We need semantic web rules.

I believe so too :)


--
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

[1] http://www.w3.org/2000/10/swap/doc/
[2] http://www.w3.org/DesignIssues/Notation3.html