Literal as subjects [was: Obsoleting URIs [was: URIs and Unique IDs]]

On 5 Nov 2008, at 21:24, Booth, David (HP Software - Boston) wrote:

>
> Yes, if there were one simple thing I could change about the RDF  
> specification it would be to remove that silly prohibition against  
> having a literal as the subject of an assertion.

I think the RDF semantics allows this, just not the RDF/XML syntax.

In Section 1.4 of http://www.w3.org/TR/rdf-mt/
[[
if E is a ground triple s p o. then I(E) = true if

s, p and o are in V, I(p) is in IP and <I(s),I(o)> is in IEXT(I(p))

otherwise I(E)= false.
]]

In section 1.3 IEXT is defined as

[[
A mapping IEXT from IP into the powerset of IR x IR i.e. the set of  
sets of pairs <x,y> with x and y in IR .
]]

IR is defined in the same paragraph as:
[[
1. A non-empty set IR of resources, called the domain or universe of I.
]]

Ie a relation can be between anything.

In RDF/XML you can always get the same effect in the end by using  
owl:sameAs in the style of this turtle:

[] owl:sameAs "http://example/new-term"^^xsd:anyURI .
    :obsoleteUri "http://example/old-term"^^xsd:anyURI .

Henry

Received on Monday, 10 November 2008 07:00:36 UTC