Re: bNodes as graph identifiers (ISSUE-131)

[ BTW, I'm CC'ing Steve, since he's not a member of the RDF Working 
Group any more.   Steve, if you want to reply to the group, please 
remember to send to public-rdf-comments@w3.org.]

On 05/31/2013 01:17 PM, Andy Seaborne wrote:
>
>
> On 31/05/13 20:27, Sandro Hawke wrote:
>>
>>
>> Andy Seaborne <andy.seaborne@epimorphics.com> wrote:
>>
>>>
>>>
>>> On 31/05/13 17:00, Sandro Hawke wrote:
>>>> On 05/29/2013 01:47 PM, Steve Harris wrote:
>>>>> [ as a side note I find it bizarre that I'm having to advocate NOT
>>>>> changing a 14
>>>>> year old, industrially deployed spec, at the 11th hour of the
>>>>> standardisation
>>>>> process, to add a feature that's used by a tiny minority of deployed
>>>>> systems -
>>>>> if anything was to strike an outsider as peculiar about this WGs
>>>>> process, it
>>>>> would surely be this feature ]
>>>>
>>>> I don't understand this complaint at all.  This Working Group is
>>>> chartered to provide a standard mechanism for working with and
>>> sharing
>>>> multiple graphs.   In the chartering process in 2010, our various
>>> inputs
>>>> all said this was a very high priority.   A lot of folks said to add
>>>> Named Graphs or fix reification or something like that.
>>>
>>> Specifically, blank nodes for graph names, not datasets in general.
>>>
>>
>> What 14-year old spec do you think Steve was referring to?
>
> Best to ask him (but I'm reading "RDF" and referring to blank nodes, 
> them not being anonymous individuals for better or worse) , simple 
> entailment, leanness etc.)
>

It seems clear to me that he was referring to RDF (which became a REC in 
1999, 14 years ago).    He seemed to be protesting changing it, so I was 
explaining why we were doing so.

If he was protesting changing the Working Group's design for handling 
graph identification -- well, that was only settled in October 2012, and 
has never been published as more than an Ordinary Working Draft.    So 
that's still relatively easy to change. (Relative to how it will be 
after Last Call, Candidate Recommendation, getting implementations, 
Proposed Recommendation, and Recommendation, let alone the passing of 14 
years.)

It seems like maybe you or he are thinking I'm somehow proposing 
changing the semantics of blank nodes in RDF.   That's certainly not my 
intention.  Is there some way that allowing blank nodes to be used as 
"graph names" in datasets would have that effect?

> BTW: Are graph literals in N3 tidy or not?

I don't know what "tidy" means in this context.   Do you mean "lean"?    
If so, I'd say that I think the usual style of N3 is to treat graphs as 
logical formulas, in which case there's no way to detect the presence of 
meaningless triples and see whether a graph is lean or not.    But there 
may be systems (even some predicates in cwm) which expose graphs at the 
syntactic level allowing this inspection; I'm not sure about that.   I'm 
fairly confident non-lean graphs would be described in N3 as entailing 
and being entailed by their lean versions, not being equal to their lean 
versions.    But as a matter of efficiency, systems might well be 
permitted to silently lean their graphs, since, as I say, this isn't 
something that would be detectable through the normal interface.

      -- Sandro


>
>>
>>>     Andy
>>
>
>

Received on Friday, 31 May 2013 21:44:39 UTC