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Re: The Ordered List Ontology

From: Bob Ferris <zazi@elbklang.net>
Date: Mon, 28 Jun 2010 20:38:02 +0200
Message-ID: <4C28EC0A.7040002@elbklang.net>
To: Aldo Gangemi <aldo.gangemi@cnr.it>
CC: Silvio Peroni <speroni@cs.unibo.it>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
Hi Aldo,
Hi Silvio,

Thanks a lot, Silvio, for the Colletion Ontology. I oversaw this 
ontology somehow.

Am 28.06.2010 16:29, schrieb Aldo Gangemi:
> Yes, I like the SWAN ontology ... I remember sometimes ago I wanted to
> modularize it and submit the modules as design patterns :).
>
> Consider that, besides the typing problem in OLO, there is a difference
> between OLO and SWAN in that OLO allows for "slots" that enable a
> designer to assign indexes to items directly, while SWAN does not have
> indexes, although they can be inferred with a query over the
> "swan:nextItem" property. SWAN has the advantage of making a clear
> distinction between sets, bags and lists.

Yes, the initial and primary access method to single slots in an ordered 
list should be olo:index. The secondary access method is its (currently) 
optional iterator olo:next as shortcut to the next slot in the list.

>
> In principle, with a RIF rule added to SWAN (or a SPARQL/SPIN add-on),
> you can get the same results as in OLO, while being able to reason with
> transitivity over a sequence relation in a list.
>
> Considering sequencing, it'd be nice to decouple transitivity and
> intransitivity (easier queries and rules), cf. the "sequence" design
> pattern in ODP [3].

The transitivity re. the 'follow issue' is also very interesting. Maybe 
we could also add it. However, I see then many triples in the transitive 
'follow properties', which implies a more complicate change mechanism. 
May one have to figure out the performances of the different approaches.

 > However, why do you want to represent ordered lists, slots and items 
 > as [ rdf:type owl:Class ] (or rdfs:Class)?

Because I like to use here the most abstract concept of a meta model. In 
the OWL world this is for me owl:Class or owl:Thing and in the RDFS 
world this is for me rdfs:Resource (as the most abstract concept 
overall) and rdfs:Class.

 > While a list is a set mathematically speaking, is there any advantage 
 > in representing the lists you want to talk about as sets?
 >
 > This has some bad consequences. In your example, SexMachine and
 > GoodFoot are inferred to be [ rdf:type owl:Class ], not only [
 > rdf:type mo:Track ]. Therefore James Brown results to be the author
 > (foaf:made) of an owl:Class (SexMachine), ehich is at least awkward
 > :).

Thanks for that hint, Aldo. I removed the rdfs:range from olo:item in 
the v 0.5 version[1].

Feel free to add further comments, suggestions, critics.

Cheers,


Bob

[1] 
http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/branches/orderedlistsonto_v03/rdf/orderedlistontology.n3
Received on Monday, 28 June 2010 18:38:33 GMT

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