Is it even possible to align RDF with LPGs via reification?

Alignment with LPGs is a stated goal for some members of this working
group. I am curious how they reconcile this with the fact that none of
the proposed changes actually permit first-class edges, only
reifications of first-class edges.

The following example seems to be highly motivating:

<<#m1 | :liz :marriedTo :richard>> [:from 1964 ; to: 1975] .
<<#m2 | :liz :marriedTo :richard>> [:from 1980; to: 2001] .

However, querying this graph using Sparql returns no data, because
neither #m1 nor #m2 are actually asserted in the graph. This is
probably not what someone from a LPG background would expect.

I can assert the triple, but then the semantics become unclear:

<<#m1 | :liz :marriedTo :richard>> [:from 1964 ; to: 1975] .
<<#m2 | :liz :marriedTo :richard>> [:from 1980; to: 2001] .
:liz :marriedTo :richard .

Which marriage does the asserted triple represent? The one from 1964,
the one from 1980, or neither?

Is there any mechanism in any of the current proposals to associate
the asserted triple (which cannot have properties in RDF) with one of
the reifications?

If there is no such mechanism, are we really aligning with LPGs? Some
use cases might be covered on the surface, but we can't truly annotate
asserted edges, we can only annotate statements about edges. This is a
subtle but meaningful distinction and seems likely to cause confusion
down the road.

Thank you, and my apologies if this point has already been discussed
and I missed it.

- Luke VanderHart

Received on Sunday, 21 April 2024 20:05:01 UTC