AW: AW: {Disarmed} Re: blank nodes (once again)

Hi Sandro!

Sandro Hawke wrote:

> Is there something in the OWL specs that says OWL doesn't work 
> (or that we're no longer in DL) if the nodes composing the lists 
> are not blank? That would be a problem.

In the OWL 2 Mapping to RDF Graphs at


many of the RDF graph patterns on the left-hand-side of inverse mapping rules from RDF to the Functional Syntax are only defined for blank nodes. See, for instance, Table 16, where you can see the differences: there are some rules that use a string "*:x", which stands for an IRI according to the definition in Chap 1, some rules which can be used with both IRIs and blank nodes, as denoted by the string "x", and some of the rules in that table are really only defined for blank nodes only, denoted by string "_:x". You can find many more examples for blank node-only rules in the other tables. 

Specifically for lists, their inverse mapping is treated by Table 3, which only handles the case of blank nodes.

OWL 2 DL parsers may, of course, decide to relax on this and also parse structures having URIs instead of blank nodes. But, strictly speaking, such RDF graphs do not count as valid OWL 2 DL ontologies in RDF graph form. 


Dipl.-Inform. Michael Schneider
Research Scientist, Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
WWW  :
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: +49-721-9654-0, Fax: +49-721-9654-959
Stiftung des bürgerlichen Rechts
Stiftung Az: 14-0563.1 Regierungspräsidium Karlsruhe
Vorstand: Dipl. Wi.-Ing. Michael Flor, Prof. Dr. rer. nat. Ralf Reussner,
Prof. Dr. rer. nat. Dr. h.c. Wolffried Stucky, Prof. Dr. rer. nat. Rudi Studer
Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus

Received on Thursday, 24 March 2011 16:08:02 UTC