Re: ISSUE-22 Recursion - Status of Core SHACL Semantics draft

On 11/17/2015 01:37 AM, Eric Prud'hommeaux wrote:
> * Peter F. Patel-Schneider <pfpschneider@gmail.com> [2015-11-16 06:09-0800]
>> On 11/16/2015 12:36 AM, Iovka Boneva wrote:
>>> Le 13/11/2015 19:33, Peter F. Patel-Schneider a écrit :
[...]

>> I do not see the point of this abstraction process, however.  Why not just
>> use RDF graphs as defined in the RDF specification instead of going through
>> this exercise?  If you need something like val, perhaps to ensure blank-node
>> indistiguishability, you can just define it directly on RDF graphs.
> 
> We used an abstraction of RDF graphs in order to treat incoming
> and outgoing edges uniformly, thus avoiding us to distinguish two
> cases (incoming, outgoing) in every single definition or theorem.

As far as can recall, all (or almost all) of the semantic interaction between
ShEx expressions and the graph are done via the intermediary of
neighbourhoods.  It seems to me then that all that would be needed to remove
the need for this abstraction is to define neighbourhoods directly from RDF
graphs, something like

The neighbourhood of a node n in an RDF graph consists of the triples of the
graph of the form < n, p, o > plus an extended triple of the form < n, ^p, s >
for each triple in the graph of the form < s, p, n >.

peter

Received on Tuesday, 17 November 2015 11:20:55 UTC