Re: Semantic Predication: 4 - more worked out examples

On 16 Feb 2023, at 19:23, Olaf Hartig <olaf.hartig@liu.se> wrote:

Or, perhaps, we are misunderstanding one another. Let me try to ask my question again: In the "<<< ... >>>" versus "<<
... >>" version of your Example 2, the data looks as follows (for clarity, I have removed the Turtle shorthand notion
with the semicolon and, instead, use a NTriples-like notation with one triple per line).

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

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

Now, if I understand your previous emails right, you say that the meaning of the dct:created property in the second of
these triples is that it is "a property stating the created date of the creating event induced by the embedded triple"
whereas the meaning of dct:created in the fourth triple is that it is "a property stating the created date of the triple
denoted by the embedded triple itself." So, the same IRI, dct:created, has two different meanings in this example. Do
you agree?

The unique meaning of dct:created has been specified by the Dublin Core community:

Vocabulary:     DCMI Metadata Terms<https://www.dublincore.org/specifications/dublin-core/dcmi-terms/>
URI     http://purl.org/dc/terms/created

Label   Date Created
Definition      Date of creation of the resource.
Comment Recommended practice is to describe the date, date/time, or period of time as recommended for the property Date, of which this is a subproperty.
Type of Term    Property
Has Range       http://www.w3.org/2000/01/rdf-schema#Literal

Subproperty of

  *   Date<https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http%3a%2f%2fpurl.org%2fdc%2felements%2f1.1%2fdate> (http://purl.org/dc/elements/1.1/date)
  *   Date<https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http%3a%2f%2fpurl.org%2fdc%2fterms%2fdate> (http://purl.org/dc/terms/date)

This property can be used in different contexts, exactly like in the example above, where the date of creation of the resource refers to a resource being a cataloging event or a triple.
What I am suggesting is that you have to look at the predication (in this case dct:created) in the context, and understand which is the context it is applied to, and make such context unambiguous — in this case specifying explicitly which meaning the embedded triple has.

If you agree, wouldn't you also agree that these two different meanings should actually be denoted by two different
IRIs?

Not "should" but "could". Indeed, any property may be specified more and more, up to it becomes a singleton property…

But even if we have two distinct IRIs for the two possible uses of dct:created in this example (as, e.g., :event-created and :triple-created), this does not avoid the necessity to disambiguate the context, by making explicit the use of <<<...>>> or <<...>>. Indeed, if you assume that the use of :event-created is enough to disambiguate the meaning of the embedded triple, then you get the same counterexample to Timothée's trick:

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

cheers
—e.