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

From: Graham Klyne <GK@dial.pipex.com>
Date: Mon, 02 Oct 2000 14:16:29 +0100
Message-Id: <>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: rdf interest <www-rdf-interest@w3.org>

I think what you describe has exactly the same effect as Jan Grant's recent 

>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).

except that Jan's approach doesn't depend on additional 
application-specific awareness.  Or am I missing something?


At 02:17 PM 9/30/00 +0100, Ian Horrocks wrote:
>In the OIL language (see http://www.ontoknowledge.org/oil/) we extend
>RDF schema with (amongst other things) logical constructs that allow
>you to say things like:
>         P --[rdfs:range]-> (A or B)
>This approach has many advantages: it allows disjunctive semantics to
>be exactly captured and it saves cluttering up the class hierarchy with
>unwanted classes. Of course the meaning would only be accessible to
>OIL-aware agents.
>In this setting, given
>         S --P--> O
>we can infer
>         O --rdf:type--> (A or B)
>Note that this is NOT the same as being able to infer either
>         (O --rdf:type--> A)
>         (O --rdf:type--> B)
>As for validity checking, without being able to express e.g., negation
>or disjointness, then "validation" is not very meaningful as we can
>never infer invalidity - we can only infer tighter constraints.
>Regards, Ian

Graham Klyne
Received on Monday, 2 October 2000 09:40:58 UTC

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