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

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)