Re: facts about web ontology languages

> This is second hand (via Jeremy Carroll), but I understand Herman ter 
> Horst presented a paper [1] showing that RDF and RDFS are decidable, 
> and further that they are decidable in polynomial time (which is 
> cheaper than DLs). I believe this also holds for RDFS + some bits of 
> OWL (fp, ifp, inv, sameAs ? i.e. not the restrictions), but with 
> intensional semantics.
>
> As for OWL Full I don't know of any papers showing it isn't decidable. 
> Yet.
>
> I'll let more knowledgeable people dive in at this point.

Totally disregarding the point about being "knowledgeable" (:)), I 
think one of the plus points that was made about OWL-DL and OWL Lite 
being DLs was the ability to use existing DL reasoners (such as RACER) 
--- i.e. OWL Full may be decidable, but no-one has written a complete 
reasoner for it.

Interesting paper pointer though... I shall have to read that!

-Richard