Re: Slides: Talking About Occurrences

antoine,

> On 27. Oct 2023, at 12:06, Antoine Zimmermann <antoine.zimmermann@emse.fr> wrote:
> 
> 
> In Slide 24, it is written "A triple is identified with the singleton set containing it", and a subtitle says "RDF 1.1 Semantics". Clearly, an element and the singleton that contains it are never the same, but they may be identified in certain contexts. I do not understand to which context you refer here. The mention of RDF 1.1 Semantics is misleading because RDF 1.1 Semantics does not have this identification. In fact, quite the opposite: if they were identified, then:
> 
> { <me> <wears> _:b . _:b a <Hat> }
> 
> would be identified with
> 
> {{<me> <wears> _:b}, {_:b a <Hat>}}
> 
> But these two sets mean different things. The second one does not imply the first one. First one says "I wear a hat", while second one says "I wear something. There exists a hat."

is that true even though it appears that the expression appears within a single document?
your note "on the semantics of rdf datasets"[1], which appeared on the same date as the "rdf 1.1 semantics" recommendation, does describe alternative interpretations.
in one of them the sets mean different things, but in the other they mean the same.
i have, however, understood the passage in section ten of the "rdf 1.1 semantics" document[2] to decide between the alternatives.
that is, i have interpreted the statement

    The graphs in a single dataset may share blank nodes.

to indicate that, where two blank node designators appear in distinct graphs in a given dataset, they are intended to designate the same node.
that is, as "if lexically identical nodes appear in distinct graphs in a dataset, the nodes are shared", rather than "if lexically identical nodes appear in distinct graphs in a dataset, the nodes may be shared."
that is, the conditionality applies to the presence rather than the sharing.
was that not the passage's intended meaning?

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[1] : https://www.w3.org/TR/rdf11-datasets/
[2] : https://www.w3.org/TR/rdf11-mt/#rdf-datasets
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james anderson | james@dydra.com | https://dydra.com

Received on Friday, 27 October 2023 14:27:04 UTC