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Re: range, domain: Conjunctive AND disjunctive semantics both supportable

From: Graham Klyne <GK@dial.pipex.com>
Date: Fri, 29 Sep 2000 13:52:17 +0100
Message-Id: <4.3.2.7.2.20000929132320.00b98cc0@pop.dial.pipex.com>
To: Jan Grant <Jan.Grant@bristol.ac.uk>
Cc: rdf interest <www-rdf-interest@w3.org>
At 10:21 AM 9/29/00 +0100, Jan Grant wrote:
>and loosely:
>
>P has a range of (a member of the union of A and B)
>
>         A --[rdfs:subclassOf]-> anon:C
>         B --[rdfs:subclassOf]-> anon:C
>         P --[rdfs:range]-> anon:C
>
>(give anon:C a real URI if you prefer).
>
>Are there problems with this scheme?

I like the approach.


I don't know if it's a _problem_, but I don't think this actually allows 
one to validate OR infer much in an open-world environment.  E.g. the above 
statements don't allow us to infer from:
        S --P--> O
the truth or falsity of any of the following:
        O --rdf:type--> A
        O --rdf:type--> B
        O --rdf:type--> D


Similarly, they don't allow us to validate a statement like:
        S --P--> O
where
        O --rdf:type--> D


I guess what it does tell us is that
        S --P--> O
where
        O --rdf:type--> A
or
        O --rdf:type--> B
is definitely valid.


#g

------------
Graham Klyne
(GK@ACM.ORG)
Received on Friday, 29 September 2000 09:50:05 GMT

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