I've been working on RDF aggregation in the context of the Mozilla platform, and had some questions about whether RDF aggregation is standardized in any way, or should be:

My primary question arises in regards to the standard rdf:Seq resources. If you are aggregating several RDF graphs, should you reorder the child arcs? For example, aggregate the following graphs:

Graph 1-A

<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.foo.com/child1>
<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.foo.com/child2>

Graph 1-B

<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.bar.com/child1>
<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.bar.com/child2>

Graph 1-aggregated

In my opinion, the logical/semantically-correct aggregation would be like so:

<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.foo.com/child1>
<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.foo.com/child2>
<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_3> <http://www.bar.com/child1>
<http://foo.com/URI> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_4> <http://www.bar.com/child2>

Now, I take on a more complicated semantic scenario. Imagine an RDF vocabulary that defines mirrors for a busy website using the property http://namespace.foo/mirrors This resource points to a rdf:Bag which contains a list of mirrors for the specified website. Assuming that the aggregator knows about this RDF namespace, can it reasonably combine the mirrors triples (and the Bag resource)? May it do so only if the Bag resource is anonymous? May it "silently" infer a rdfs:sameAs relationship between the "two" bags involved?

Graph 2-A

<http://foo.com/> <http://namespace.foo/mirrors> _:mylist
_:mylist <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Seq>
_:mylist <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.bar.com/mirror/foo.com/>
_:mylist <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.baz.com/mirror-foo/>

Graph 2-B

<http://foo.com/> <http://namespace.foo/mirrors> _:mylist2
_:mylist2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Seq>
_:mylist2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.personal.us/foo>
_:mylist2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.backup.de/foo>

Graph 2-aggregated

<http://foo.com/> <http://namespace.foo/mirrors> _:node
_:node <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Seq>
_:node <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> <http://www.bar.com/mirror/foo.com/>
_:node <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> <http://www.baz.com/mirror-foo/>
_:node <http://www.w3.org/1999/02/22-rdf-syntax-ns#_3> <http://www.personal.us/foo>
_:node <http://www.w3.org/1999/02/22-rdf-syntax-ns#_4> <http://lists.w3.org/Archives/Public/www-rdf-interest/>