more about dereference (notes from MIT post F2F2-day-1)

Some of us kept talking for a few more hours.    Everyone was
more-or-less cool with these observations about dereference:

1. If a system successfully dereferences URL "L" and obtains a
representation of an RDF graph, then <L> is a GraphContainer.  That
is, "L" denotes a GraphContainer.  Logically, GraphContainer is
disjoint from foaf:Person (I think!!) so a document that includes "<>
a foaf:Person" is (by this proposal) logically inconsistent with it
being served on the Web.
 
2. So, owl:Ontology heavily overlaps GraphContainer.  It might even be
a subclass of it.  (Many OWL ontologies say "<> a owl:Ontology", where
the <> will be resolved to the address the ontologies is fetched from,
aka L.)

3. Some GraphContainers, "SerialGraphContainers" are functions mapping
from time to RDF Graphs.  We can talk about next & previous & current
RDF Graphs in a SerialGraphContainer, but not about GraphContainers in
general.  (cf facebook's api for fetching RDF data, which returns
different RDF data depending on your credentials).

4. A ConstantGraphContainer always holds the same RDF Graph.  This can
be used for when you want to attach a dereferenceable URL to a g-snap.
You put it in a ConstantGraphContainer.

Received on Wednesday, 12 October 2011 21:04:13 UTC