On Sep 20, 2013, at 2:45 AM, Pat Hayes <[email protected]> wrote:
> In the original paper that Jeremy and I (and Chris Bizer) co-wrote, we
> defined a named graph to be a <name, graph> pair, so the statement
>
> GRAPH x:g1 { :a :b :c .}
>
> would mean that the IRI x:g1 denotes the pair < x:g1, { :a :b :c .} >. But
> if someone were to object that this is artificial and unintuitive, I would
> not defend it overly strongly.
Patrick Stickler was our fourth author.
This actually works; I had forgotten. But it gives all the rights answers to
all the test cases.
This suggests a different fix that achieves my personal goals and would satisfy
*my* objections
Ah, I just reread:
[[
An RDF dataset (see [RDF11-CONCEPTS]) is a finite set of RDF graphs each paired
with an IRI or blank node called the graph name, plus a default graph, without
a name. Graphs in a single dataset may share blank nodes. The association of
graph name IRIs with graphs is used by SPARQL [RDF-SPARQL-QUERY] to allow
queries to be directed against particular graphs.
Graph names in a dataset may refer to something other than the graph they are
paired with. This allows IRI referring to other kinds of entities, such as
persons, to be used in a dataset to identifygraphs of information relevant to
the entity denoted by the graph name IRI.
When a graph name is used inside RDF triples in a dataset it may or may not
refer to the graph it names. The semantics does not require, nor should RDF
engines presume, without some external reason to do so, that graph names used
in RDF triples refer to the graph they name.
RDF datasets may be used to express RDF content. When used in this way, a
dataset should be understood to have at least the same content as its default
graph. Note however that replacing the default graph of a dataset by a
logically equivalent graph will not in general produce a structurally similar
dataset, since it may for example disrupt co-occurrences of blank nodes between
the default graph and other graphs in the dataset, which may be important for
reasons other than the semantics of the graphs in the dataset.
Other semantic extensions and entailment regimes may place further semantic
conditions and restrictions on RDF datasets, just as with RDF graphs. One such
extension, for example, could set up a modal-like interpretation structure so
that entailment between datasets would require RDF graph entailments between
the graphs with the same name (adding in empty graphs as required).
]]
hmm, I think I need to update my comment to indicate that on its resolution
that paragraph should probably change.
Here is a different version.
[[
An RDF dataset (see [RDF11-CONCEPTS]) is a finite set of RDF graphs each paired
with an IRI or blank node called the graph name, plus a default graph, without
a name. Graphs in a single dataset may share blank nodes. The association of
graph name IRIs with graphs is used by SPARQL [RDF-SPARQL-QUERY] to allow
queries to be directed against particular graphs.
An RDF interpretation I conforms with the naming of a dataset, if for each
graph name gn, I(g) is the pair < gn, G > where G is the graph associated with
gn by the dataset.
An RDF interpretation I of a graph within a dataset SHOULD conform with the
naming of the dataset.
While graph names in a dataset may **lower case deliberate** refer to some
other kind of entity, such as persons, this may cause confusion and is not
RECOMMENDED.
RDF datasets may be used to express RDF content. When used in this way, a
dataset should be understood to have at least the same content as its default
graph. Note however that replacing the default graph of a dataset by a
logically equivalent graph will not in general produce a structurally similar
dataset, since it may for example disrupt co-occurrences of blank nodes between
the default graph and other graphs in the dataset, which may be important for
reasons other than the semantics of the graphs in the dataset.
Other semantic extensions and entailment regimes may place further semantic
conditions and restrictions on RDF datasets, just as with RDF graphs. One such
extension, for example, could set up a modal-like interpretation structure so
that entailment between datasets would require RDF graph entailments between
the graphs with the same name (adding in empty graphs as required).
]]
(I didn't really understand the last two sentences and just left them unchanged
and crossed my fingers)
And then any changes to concepts would be merely editorial.
Jeremy
