- From: Bob Ferris <zazi@elbklang.net>
- Date: Mon, 28 Jun 2010 20:38:02 +0200
- 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 UTC