Re: Semantic Predication: 4 - more worked out examples

On 16 Feb 2023, at 17:53, Olaf Hartig <olaf.hartig@liu.se> wrote:

Hi Enrico,

On Thu, 2023-02-16 at 16:06 +0000, Franconi Enrico wrote:
Notice also that the relationship type 'created' is perhaps a bit
special in the sense that it may have both a referentially opaque
interpretation and a referentially transparent one (so, in a way,
it has two meanings, and these can be separated by using two
different IRIs). While there are certainly more examples of such
types of relationships, I would think that for most types of
relationships only one of the two interpretations makes sense.

Yes.

Let me emphasise this: YES!
This shows that the important bit to look at, in order to understand
which meaning an embedded triple has, is the predication.
In the dct:created case, the meanings are more precisely: (1) a
property stating the created date of the creating event induced by
the embedded triple; (2) a property stating the created date of the
triple denoted by the embedded triple itself.

I agree!

In this case, however, doesn't the fact that there are two meanings
justify the need for two separate IRIs, where each of them captures one
of these meanings?

Then, shouldn't the "<<< ... >>>" versus "<< ... >>" version of your
Example 2 also use two different IRIs rather than overloading
'dct:created' with both meanings?

No, since the counterexample to Timothée's trick with :transparentType applies also here.
—e.

—e.


Feb 15, 2023 15:54:52 Franconi Enrico <franconi@inf.unibz.it>:
Ooops, you are right. Just a typo among so many examples…
Let me rephrase.

EXAMPLE 2 (Is TEP a good solution?):

this example shows why it is better to have a syntactic way to
characterise semantic embedded triples as opposed to use the
TEP facility.

<<< :catalog-entry-1 dct:creator :alice >>> rdf:type
:cataloging ;
                                           dct:created "2022-
07-01"^^xsd:date .

<< :catalog-entry-1 dct:creator :mary >> rdf:type unstar:triple
;
                                        dct:created "2022-08-
04"^^xsd:date .

vs the non-compositional solution with TEP:

<< :catalog-entry-1 dct:creator :alice >> rdf:type :cataloging
;
                                         :created1 "2022-07-
01"^^xsd:date .

<< :catalog-entry-1 dct:creator :mary >> rdf:type unstar:triple
;
                                        :created2 "2022-08-
04"^^xsd:date .

:created1 rdfs:subPropertyOf dct:created .
:created2 rdfs:subPropertyOf dct:created .
:created1 rdf:type rdf-star:TransparencyEnablingProperty .
:catalog-entry-1 dct:creator :alice .

(still not nice)

I believe that your solution below does not work, since the
transparency stated for the embedded triple by :transparentType
(cool trick!) does not apply when the same embedded triple is
the subject of dct:created property, according to the
compositional semantics of RDF. This is clear when you remove
the semicolon to get a N-Triples syntax.
I still believe that the transparency of an embedded triple
depends by its occurrence, not by its context; in this way, the
semantics remains purely compositional and directly
understandable.
cheers
—e.

On 15 Feb 2023, at 12:50, Timothée Haudebourg <
timothee.haudebourg@spruceid.com> wrote:

Hi,

about your Example 2, I think the rdf-
star:TransparencyEnablingProperty is supposed to be the type
of the property applied on the quoted triple, not the type of
the property inside the quoted triple. So the solution with
TEP would be:

<< :catalog-entry-1 :creator :alice >> :transparentType
:cataloging ;
                                      dct:created "2022-07-
01"^^xsd:date .

<< :catalog-entry-1 :creator :mary >> rdf:type unstar:triple
;
                                     dct:created "2022-08-
04"^^xsd:date .

:transparentType rdfs:subPropertyOf rdf:type .
:transparentType rdf:type rdf-
star:TransparencyEnablingProperty .
:catalog-entry-1 :creator :alice .

Maybe we could provide a standard rdf:transparentType if this
use case is so common? In which case the example would
become:

<< :catalog-entry-1 :creator :alice >> rdf:transparentType
:cataloging ;
                                      dct:created "2022-07-
01"^^xsd:date .

<< :catalog-entry-1 :creator :mary >> rdf:type unstar:triple
;
                                     dct:created "2022-08-
04"^^xsd:date .

:catalog-entry-1 :creator :alice .

It doesn't look so bad to me anymore.

Best,