Thank you, Dave R. I think this hits the nail on the head. I view the 
individual named graphs in the Fuseki/TDB Dataset as not having to be 
self-contained. I attempted to make them that way to be able to browse them in 
TopBraid. They are separate for data management purposes, as you suggest.

I think the issue I mentioned with TopBraid happens because it expects 
everything it reads to be a self-contained ontology document and so it 
complains if it isn't. It expects to find an owl:Ontology with the same name as 
the base URI; at least that's what it creates to "fix" an incomplete one, and 
that does seem to be a pretty standard pattern for other ontologies.

The only drawback of accommodating this (from my point of view) is that either 
I use the same base URI and Ontology URI for each graph model, or make them 
unique and end up (I believe) with extra Ontology individuals if I do use the 
union graph or otherwise concatenate multiple models.

Dave Lebling

-----Original Message-----
From: Dave Reynolds [mailto:[email protected]] 

Hmm. There's two assumptions there which may not be warranted for David's case 
but only he can tell.

Firstly, you are assuming that there is some value in having the data be legal 
OWL/DL. A large part of the point of RDF is the whole open world assumption. 
There is no need at the RDF level (or indeed OWL with RDF
semantics) to have every document be self contained in this way. This is not 
about what Jena models allows it as about what RDF allows and what OWL profile 
you need to support (if any).

Secondly, even if David needs OWL DL compliance somewhere it is not clear that 
each named graph in a DataSet needs to be separately a self-contained ontology. 
David seems to have a separate named graph for each individual. I would suspect 
that he regards the ontology as being the union of a set of those named graphs 
(might even be doing this via a union-default in TDB). In which case perhaps it 
is only the Union that needs to be DL compliant and have relevant import 
statements - not every individual component graph (which may there just for 
data management purposes).

Dave

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