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

Note that N3 provides a convenient syntax for reversing the direction of 
a predicate, so you don't have to define its inverse.  From the N3 
documentation:
https://www.w3.org/TeamSubmission/n3/#shorthand

[[
Paths

These are just shorthand. x!p means [ is p of x ] in the above anonymous 
node notation. You can read it as "x's p". This is a little reminiscent 
of the "." in object oriented programming "object.slot" syntax.

The reverse traversal, x^p means [ p x ] . For either forward or 
backward traversal, p is a property, and x can be a whole path with both 
! and ^ in it.

Example:

:joe!fam:mother!loc:office!loc:zip Joe's mother's office's zipcode

:joe!fam:mother^fam:mother Anyone whose mother is Joe's mother.
]]

Thanks,
David Booth

On 10/30/23 12:52, Miguel wrote:
> 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 <mailto: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/ <http://www.emse.fr/~zimmermann/>
>

Received on Monday, 30 October 2023 18:21:16 UTC