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RE: RDF *already* supports literal subjects - a thought experiment

From: Houghton,Andrew <houghtoa@oclc.org>
Date: Tue, 13 Jul 2010 09:56:13 -0400
Message-ID: <6548F17059905B48B2A6F28CE3692BAA0758A81B@OAEXCH4SERVER.oa.oclc.org>
To: "Semantic Web" <semantic-web@w3.org>
> From: semantic-web-request@w3.org [mailto:semantic-web-request@w3.org]
> On Behalf Of Pat Hayes
> Sent: Monday, July 12, 2010 07:12 PM
> To: Graham Klyne
> Cc: Sandro Hawke; Semantic Web
> Subject: Re: RDF *already* supports literal subjects - a thought
> experiment
> 
> First, as others have noted, we do already have a workable, if ugly,
> way to state what anyone might need to state with a literal subject in
> RDF already: instead of writing the obvious
> 
> <literal> :p :o .
> 
> one can write
> 
> _:x :same <literal> .
> _:x :p :o .
> 
> using whatever form of :same one prefers, such as owl:sameAs. So we
> don't need another complicated work-around. The point of allowing
> literals as subjects was to avoid having to use a work-around, not to
> invent a new one; and also, in fact, to simplify RDF and make it more
> elegant, also not a purpose which is served by yet another work-
> around. So this idea doesn't really help.

First let me say that I don't fully understand the issues here, I
am not a expert, but I am trying to make sense of these issues in
the context of my current and future semantic web practice. What 
Pat mentioned, above, actually made sense to me given the following 
statement in the RDF concepts document:

 <http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#section-Literals>

 3.4 Literals
 Literals are used to identify values such as numbers and dates by means
 of a lexical representation. Anything represented by a literal could 
 also be represented by a URI, but it is often more convenient or 
 intuitive to use literals."

If *anything* represented by a literal could also be represented by a
URI, then:

_:x owl:sameAs <literal> .
_:x :p :o .

makes perfect sense to me. However, wouldn't the range of owl:sameAs
need to be expanded to include literals?


Andy. 
Received on Tuesday, 13 July 2010 13:56:43 GMT

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