Re: Equality of RDF bags

On 1 November 2011 09:59, Mischa Tuffield <> wrote:

> Leaning can only be applied when the bnodes have the same edges in a graph.

To be precise, you only need the edges of a blank node to be a *subset* of
the edges of another in order to leanify by collapsing the first into the
second. Two blank nodes having exactly the same edges in a graph would mean
you can leanify the graph in (at least) two different ways (that is, with a
homomorphism that maps the first to the second, or with a homomorphism that
maps the second to the first).

> Finally, I am not aware of any RDF/SPARQL stores which do leaning, am not
> sure it happens much in practice, but I could be wrong.

It probably doesn't happen in practice at all, so I guess this is more of a
discussion for the purists.



Received on Sunday, 6 November 2011 14:16:30 UTC