W3C home > Mailing lists > Public > www-rdf-comments@w3.org > October to December 2001

Re: RDF Schema datatypes and RDF Core WG MT

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Wed, 10 Oct 2001 15:34:22 -0500
Message-Id: <p05101048b7ea5ea3148e@[205.160.76.193]>
To: www-rdf-comments@w3.org
Peter-

Re. your proposal, I emphatically don't agree with your point 2. 
There are two different issues here: syntactic datatyping, and 
assertion of membership in a class. The first can reasonably entail 
the second, but it shouldn't be *identified* with it. To do that is 
essentially to abandon the utility of  literals in the first place, 
in my view, since it means that the task of determining the datatype 
of a literal is the general inference problem. There is no way to 
distinguish semantically between the case where an RDFS graph 
contains an explicit rdfs:range triple, and the case where the range 
is inferred by an arbitrarily long inference chain from other 
information in the graph. Note that in your example, the fact that 
"07" is a literal is irrelevant to the reasoning; you could replace 
the literals by a URI and reach the same conclusions.

Mary age "07" .
age rdfs:range ????:integer .

There are other problems, in any case. For example, suppose that (as 
is perfectly legal in rdfs) that several rdfs:range assertions are 
made about age; what is the datatype of the literal in this case?

I would urge that this not be adopted as a general mechanism for 
literal datatyping.

Pat Hayes

-- 
---------------------------------------------------------------------
IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola,  FL 32501			(850)202 4440   fax
phayes@ai.uwf.edu 
http://www.coginst.uwf.edu/~phayes
Received on Wednesday, 10 October 2001 16:34:26 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:15:16 UTC