Re: Urgent! Semantic question about rdfs:domain.

From: pat hayes (
Date: 04/25/01

>Pat, I believe the current semantics are correct. The RDF Schema Spec
>(sect. 3.1.4) says that rdfs:domain is "used to indicate the class(es)
>on whose members a property can be used." To me, this indicates that an
>instance of the class does not have to have a value for that property,
>i.e., that there could be some Animals for which there is no hasParent
>property, but any thing with a hasParent property must be an Animal.

Interesting. To me, that form of words suggests the oppposite 
interpretation. (If a property has no value for some individual then 
it cannot be "used" on that individual, surely? If it gets used, what 
is the value of the property?)

The real moral is that vaguely worded specifications are worse than useless.

OK, but I will take your advice. My problem now is that I don't feel 
competent to rewrite the walkthru explanations, as I no longer feel 
that I really follow the intended interpretation of properties and 
domains. As far as I can see, with this interpretation, there is 
never any point in declaring a domain or a range. Those statements 
have no utility, since they do not allow a reasoner to draw any 


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