Re: Tentative contribution to the "URI issue"

>> The question is how does one differentiate URIs from strings.
>> Are they strings? Should they be? If all we (collectively) want
>> is to write "http://jos@debrujin.com/salary"("2020-11-22", "E100000")
>> where "..." are strings, then there is no problem.
>> But I don't think think this is what we collectively had in mind.
>> I believe we wanted to distinguish URIs from strings and other types of
>> constants.
>
> Distinguishing symbolic constants identified by a URI from literal
> constants such as strings and integers still seems like a syntax issue
> addressable at that level in the way proposed earlier.
+1 Indeed. This issue is completely orthogonal to the issue of sorts.
>
> The conceptual proposal is that we *only* have symbolic constants
> identified by a URI and literal constants (strings, integers etc) and
> only the former are allowed to have boolean and arrow sorts.
>
>> There is also an issue of signatures when we will start allowing or
>> disallowing certain individuals to play roles of predicates, functions,
>> etc.  We cannot assign a signature to any given constant, so sorts
>> could be
>> one of the grouping mechanisms here. For instance, if a dialect
>> (like, say,
>> WSML) allows only URIs to be concepts then only the constants of the
>> sort
>> rif:uri will have Boolean signatures.
>
> What I was asking for in the meeting and my earlier message was what's
> the use case where we would allow something *other* than symbolic
> constants identified by a URI to be used as concepts?  The point being
> that I'm not convinced there is one.
>
> I can see the value in having those symbolic constants be sorted but
> they would still be identified by URIs. [*]
Agreed.
>
> In which case perhaps all we are asking is "what's the name for the
> top sort?".
>
> If so then in RDF terms that is rdfs:Resource - everything in your
> domain is an rdfs:Resource including literals, people, unicorns and
> web information resources.
>
> If you want a sort which is disjoint from literals (strings, integers
> etc) then from an OWL/DL point of view that would be owl:Thing.
>
> Dave
>
>
> [*] Indeed in a sorted semantic web compatible dialect then one might
> identify RIF sorts with RDF Classes so in that dialect you could say
> things like:
>
>   all symbols of rdf:type owl:DatatypeProperty have a RIF boolean
>   signature:
>      OWL:Thing * rdfs:Literal
>
> but you could also then have application-specific sorts defined using
> RDFS/OWL ontologies.
>
>
>
>
>
>

-- 
Jos de Bruijn,        http://www.debruijn.net/
+43 512 507 6475         jos.debruijn@deri.org
DERI                      http://www.deri.org/
----------------------------------------------
Simple, clear purpose and principles give rise 
to complex and intelligent behavior.  Complex 
rules and regulations give rise to simple and 
stupid behavior.
 - Dee Hock

Received on Wednesday, 21 March 2007 12:08:51 UTC