Re: Does rdfs:superClassOf (or equivalent) exist?

Hi Harshvardhan,
just to further elaborate, with that argument you could support the
explicit definition of the inverse of any object property (excluding
symmetric properties).
Some vocabularies do indeed adopt that convention.

The problem with that is that at the syntactic level you have always two
ways (for each pair of related resources) to represent the same meaning.
Only if you explicitly state in OWL the relationship between the two
properties with the inverseOf expression *and* perform inference, then the
two versions are reconciled.

Furthermore, the direction in which a property is defined does not (at
least in theory) imply a specific favoured direction for traversing it, as
shown in the SPARQL examples by Antoine Zimmermann.

Best regards,
Miguel

On Mon, Oct 30, 2023 at 5:47 PM Antoine Zimmermann <
antoine.zimmermann@emse.fr> wrote:

> rdfs:superClassOf (respectively rdfs:superPropertyOf) does not exist in
> any standard, nor any term equivalent to it.
>
> If it did, it would not add anything to reasoning or querying. If you
> want to list all subclasses of a class <C>, you can write:
>
>   SELECT ?subclass WHERE {
>     ?subclass  rdfs:subClassOf  <C> .
>   }
>
> and if you want the list of superclasses of a class <C>, you write:
>
>   SELECT ?superclass WHERE {
>     <C>  rdfs:subClassOf  ?superclass .
>   }
>
>
> What use cases would make it harder and more painful to write:
>
>   :A  rdfs:subClassOf  :B
>
> than:
>
>   :B  rdfs:superClassOf  :A
>
> ?
>
>
> --AZ
>
> Le 28/10/2023 à 14:21, Harshvardhan J. Pandit a écrit :
> > Hi.
> > We have rdfs:subClassOf defined in a standardised specification (RDFS).
> > RDFS several times mentions 'superclass', but AFAIK there is no property
> > or relation to make this explicit, i.e.
> >
> > ```turtle
> > :A rdfs:subClassOf :B . # exists
> > :B rdfs:superClassOf :A . # does this exist anywhere?
> > ```
> >
> > I can intuit why subclass relations are the most common and preferred
> > methods of use - because anyone can extend the superclass from anywhere.
> > And that either assertion can be inferred from the other (sub to super,
> > vice-versa), but I also think having the superclass be 'aware' of
> > subclasses is a good practice in maintaining ontologies e.g. to get a
> > list of all subclasses which would normally require a query each time.
> >
> > (Likewise for rdfs:subPropertyOf and rdfs:superPropertyOf)
> >
> > Apologies in advance if this has already been answered somewhere (I
> > would appreciate it if you point me to it).
> >
> > Regards,
>
> --
> Antoine Zimmermann
> École des Mines de Saint-Étienne
> 158 cours Fauriel
> CS 62362
> 42023 Saint-Étienne Cedex 2
> France
> Tél:+33(0)4 77 49 97 02
> http://www.emse.fr/~zimmermann/
>
>