labelled property graphs vs -star extension of RDFn vs -star extension of named graphs

At the teleconference yesterday I mentioned that there could be user-visible 
differences between different views of how to proceed, even when there is some 
consensus that different views are essentially the same.

Here is one example of a user-visible divergence.  Consider the following 
input, written in the community group syntax.

:liz :spouse :dick {| :start 1964; :end 1974 |} .
:liz :spouse :dick {| :start 1975; :end 1976 |} .

In the community graph version of RDF-star this results in one asserted triple 
with subject :liz that is the subject of four triples.  In SPARQL-star, the BGP

:liz :spouse :dick {| :start 1964; :end 1976 |} .

would match against a graph constructed from this input.

In labelled property graphs this would appear to result in two asserted 
triples with subject :liz, each with two property-value pairs.  The above BGP 
would not match.

So there is a decided visible difference between the community graph version 
of RDF-star and labelled property graphs.

If I am correct in reading the (sparse) information available about RDFn, a 
-star extension of RDFn would conform to the community group reading.  So 
there would be noticeable differences between an extended RDFn and labelled 
property graphs.

I am not aware of any proposal for using named graphs that says what the above 
would result in there, so it is unclear which side a named graphs version of 
-star would fit into.

peter

Received on Friday, 8 December 2023 14:18:11 UTC