Re: UNSAID - two test cases

On Wed, 2004-12-22 at 10:26 +0000, Seaborne, Andy wrote:
[...]
> ==== Case 1: selecting a resource based on the absence of a type triple:
> 
> An example like this has just been asked on jena-dev.
> 
> "Find all the things that are not of a given class."

Please let's be *very* careful about negation vs. UNSAID.
This query does *not* find all the things that are
not of a given class. It finds things that are not
stated (directly, i.e. by way of rdf:type) in the input data
to be of a given class.

> == Query 1:
> PREFIX : <http://example.org/ns#>
> 
> SELECT ?r
> WHERE (?r rdf:type ?type)        # Get all the things with a type
>        UNSAID (?r rdf:type :foo)

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
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