Re: multisets everywhere

Earlier Ted wrote:

> Operating on this universal and eternal truth assumption, all
> graphs in the universe could be combined, and there would be no
> contradictions, and all queries should deliver results that are
> likewise universally and eternally true.
>
> This belief has been problematic since RDF began, and it is
> likely to continue to be so for many years if not forever.
>
> In RDF 1.1, it was explicitly stated that any given graph must
> be treated as a snapshot of a universe, just a moment in time
> (though still treated as if entirely true about that moment),
> and should only be blended (merged, unionized) with other graphs
> that described the same moment in time.
>

I agree. IMO time and space are the dimensions we exist in and should get
special treatment.

Just for discussion's sake, consider
> two people, one to the north and one to the south of a fire,
> describing that fire.  The wind was blowing west-to-east, so
> smoke could accurately be described as drifting east -- but
> the observers described it instead as drifting to the right
> in one case and to the left in the other -- and both were
> indeed accurate, but neither was *fully* accurate....
>

I think this is solved by the spatial bound I suggested earlier (T1 and T2
could be blank if desired by using underscores in their positions, which
would mean "unbounded"):

DistantSmoke isDrifting Left T1 T2 LosAngeles
DistantSmoke isDrifting Right T1 T2 SanDiego

The only way to *know* whether any two Named Graphs were about
> the same moment in time is for those two Named Graphs to be
> explicitly described as such.
>

Being able to add this information at the statement level would give full
granularity. A full statement would look like the following and the last
four positions could be blank if desired:

Subject Relation Object T1 T2 SpatialBound Certainty

Going back to what I said earlier when talking about linguistics:

> Because any statement type can be nested in any other statement type you
> then see that everything can be expressed using only complex statements at
> the top level.
>

This is basically what Wikidata is doing, and is actually quite clever by
them IMO. Wikidata also addresses referential opacity in an elegant way,
albeit their "snak" terminology is awful. It basically groups referentially
transparent fragments and referentially opaque fragments separately, and
the referentially opaque fragments refer to the entire n-ary relationship
preceding them. Incorporating the temporal and spatial positions, an
example would be something like:

:RichardB :marriedTo :LizT 1964 1974
  []
  [
    :statedBy :Bob
    :statedIn :Wikipedia
    :recorded "2021-07-07"^^xsd:date
  ]

The empty set essentially means "no referentially transparent fragments".

A more complex example would be something like:

:LizT :starredIn :JaneEyre 1943 1943
  [
    :role :HelenBurns
    :pay-USD 10000
  ]
  [
    :statedBy :Bob
    :statedIn :Wikipedia
    :recorded "2021-07-07"^^xsd:date
  ]

The sets are optional just to be clear, and no more need for "statementOf"
or "occurrenceOf" relations I think.

To get even more complex, the statement fragments are basically statements
without the subject, so that means they can also have time, space, and
certainty positions, and that actually marries very well when thinking of
relationships as events and the fact that events can have subevents.

Regards
Anthony


On Fri, Dec 24, 2021 at 4:30 AM Ted Thibodeau Jr <tthibodeau@openlinksw.com>
wrote:

> On Dec 21, 2021, at 03:23 PM, Pierre-Antoine Champin <
> pierre-antoine.champin@ercim.eu> wrote:
>
>
> In RDF semantics (both the current standard and the proposed RDF-star), a
> triple is either true or false.
>
>
>
> I believe this is the first time I've known anyone to suggest
> that an RDF triple could be (semantically known to be) false.
>
> How do you know whether a given triple is false?  Or, true?
>
> My understanding has been that the original conception of RDF
> was that it would only be used to record universal and eternal
> facts; in other words, everything encoded in RDF was universal
> and eternal truth.
>
> (This was an immediate problem, because we all hopefully know
> that description accuracy requires that those descriptions be
> changeable over time, but it was hard enough for many to grasp
> the simplicity of describing everything with SPO triples that
> it took years for many to realize that few descriptions were
> eternally accurate.)
>
> On this basis, even though RDF officially and explicitly operates
> under the "Open World" assumption (where anything that is not
> stated is implied and should be inferred to be unknown), *some*
> unasserted values were in practice treated as if they had been
> asserted -- i.e., that once inscribed, a triple was now, had
> always been, and would always be, accurate.
>
> Operating on this universal and eternal truth assumption, all
> graphs in the universe could be combined, and there would be no
> contradictions, and all queries should deliver results that are
> likewise universally and eternally true.
>
> This belief has been problematic since RDF began, and it is
> likely to continue to be so for many years if not forever.
>
> In RDF 1.1, it was explicitly stated that any given graph must
> be treated as a snapshot of a universe, just a moment in time
> (though still treated as if entirely true about that moment),
> and should only be blended (merged, unionized) with other graphs
> that described the same moment in time.
>
> The only way to *know* whether any two Named Graphs were about
> the same moment in time is for those two Named Graphs to be
> explicitly described as such.  Often enough, even with this
> improvement, two observers who inscribed descriptions that
> were accurate from their perspective, included to few details
> about what made up their perspective for others to accurately
> determine which graphs were from that same perspective, and
> which were different.  (Just for discussion's sake, consider
> two people, one to the north and one to the south of a fire,
> describing that fire.  The wind was blowing west-to-east, so
> smoke could accurately be described as drifting east -- but
> the observers described it instead as drifting to the right
> in one case and to the left in the other -- and both were
> indeed accurate, but neither was *fully* accurate....)
>
> All of which is to say, "This is far more complex than it
> appears when we say 'S P O [G]' is all you need to describe
> anything!"
>
> Be seeing you,
>
> Ted
>
>
>
>