- From: <jos.deroo.jd@belgium.agfa.com>
- Date: Wed, 30 Jan 2002 12:24:33 +0100
- To: jjc@hplb.hpl.hp.com
- Cc: w3c-rdfcore-wg@w3.org
[...] > This framework allows me to illustrate an aspect of my "can't live" issue > with S-B. > > S-B allows range constraints, in this example perhaps: > > <dc:title> <rdfs:range> <xsd:string.lex> . > <age> <rdfs:range> <xsd:integer.lex> . > > I currently understand S-B as, within the RDF datatyping layer, insisting > that "10" is a string. > The two range constraints are used to: > - constrain the set of possible strings > - act as a hint to the application layer that: > * type conversion is possible > * type conversion is desirable. > > Thus given the database and the schema the application processing will > correctly treat the title as a string, and the age as an integer. Good. > > Now, the query also operates in the application layer. > This returns true. > > Thus in the application layer we have the following facts being the case: > The film has the title "10". > mary has age 10. > The age of mary is the title of the film. > i.e. that 10 is "10" > > There is a type clash here, and the combination is a logical error. I don't follow Jeremy i.e I don't see how you can draw the S-B conclusion The age of mary is the title of the film. (where I suppose you mean age-value and title-value) given :Mary :age "10" . :film :title "10" . :age rdfs:range xsd:int.lex . :title rdfs:range xsd:string.lex . the query :Mary :age _:x . :film :title _:x . will succeed and I don't see any problem with that nothing can be deduced w.r.t. values i.e. dt1(v1) = dt2(v2) does *not* mean that v1 = v2 -- Jos
Received on Wednesday, 30 January 2002 06:26:08 UTC