Re: rdf:reifies many-to-many vs. many-to-one

> On Apr 3, 2024, at 10:43 AM, Kurt Cagle <kurt.cagle@gmail.com> wrote:
> 
> I have a question for clarification. I've noticed a shift to the notation:
> 
> <<(:s :p :o)>>
> 
> from 
> 
> << :s :p :o >>
> 
> Is there a distinction between the two, or simply a new syntax?

In the CG report, the << :s :p :o >> syntax was used for a quoted triple. Because of various issues with this, RDF 1.2 now uses <<( :s :p :o )>> for a Triple Term, which is intended to mostly be used as an implicit part of a “reifier”. A “reifier” has the same syntax is the CG version << :s :p :o >> and can have an optional identifier, << :id | :s :p :o >> which is effectively syntactic sugar for :id rdf:reifies <<( :s :p :o )>> .

The state of RDF Concepts is in the middle of this transition, we haven’t even agreed on the name of a “reifier”, much less the semantics. N-Triples does not include the reifier syntactic sugar and only supports the use of Triple Terms directly.

> Kurt Cagle
> Editor in Chief
> The Cagle Report
> kurt.cagle@gmail.com <mailto:kurt.cagle@gmail.com>
> 443-837-8725 <http://voice.google.com/calls?a=nc,%2B14438378725>
> 
> On Wed, Apr 3, 2024 at 10:01 AM Franconi Enrico <franconi@inf.unibz.it <mailto:franconi@inf.unibz.it>> wrote:
>> On 3 Apr 2024, at 18:56, Gregory Williams <greg@evilfunhouse.com <mailto:greg@evilfunhouse.com>> wrote:
>>> 
>>>> On Apr 3, 2024, at 8:19 AM, Franconi Enrico <franconi@inf.unibz.it <mailto:franconi@inf.unibz.it>> wrote:
>>>> 
>>>> Ora wrote: "While the primary use-case for reifications may be 1-1, …”.
>>>> In these specific 1-1 cases, I believe that instead of:
>>>> 
>>>> :e rdf:reifies <<( :s :p :o )>> .
>>>> :e :p1 :o1 .
>>>> 
>>>> you should write directly:
>>>> 
>>>>  <<( :s :p :o )>> :p1 :o1 .
>>>> 
>>>> since this implicitly implements a 1-1 relationship.
>>> 
>>> For LPG interop use-cases, we want to be able to uniquely identify occurrences of triples (edges). Your proposed alternative wouldn’t capture the same semantics, as it would be asserting properties of the triple term itself, not on a specific occurrence of that triple.
>> 
>> My proposed alternative would surely capture the one-to-one cases, as I specified. LPG use cases are many-to-one, and my example above would not work for them, as you correctly point out.
>> —e.
>>