RE: RDF validity question

Mark,

 

Thank you for your quick response. 

As my old math teacher used to say: "If you don't understand it, at least
admire it".

 

Please help me understand by commenting on my rationale.

 

At ontology level I define that valves have actuators, eventually with a
cardinality. I define that as shown. 

The purpose of that is to define an object information model, like an empty
fill-in-the-blanks data sheet.

 

That is done in order to provide the software to validate information about
individual valves, or to call for information about the actuator of a
particular valve.

When that data field is completed you can validate that that is indeed an
instance of ValveActuator (all instances are declared and typed).

 

So, yes, I want to use RDFS as a genuine schema. Please bear with me:

1.	rdf:Property is a class that is an instance of rdfs:Class
2.	an Abox instance of rdf:Property defines the criteria of membership
of that rdf:Property, as defined by the rdfs:domain and rdfs:range.
3.	that Abox instance of rdf:Property can be typed with that Tbox
Property and, my guess, use rdfs:domain and rdfs:range to show which
resources are linked by it
4.	and have metadata (effectivity, status, access rights, etc)
5.	SPARQL can handle these semantics, no need for OWL.

 

The next question might reveal my ignorance: Could this be the link to
Property Graphs?

 

To answer your question about dateTime: We aim at a perdurant storage of
information, so persistently storing state changes over many years (think of
personal medical information, but then for a process plant and its
equipment).

The valve ex:34543 may, later, get another actuator, and this information
replaces the older information, where the latter keeps being on record.

 

RDF, to me, seems to have a focus documenting a particular state, valid at a
particular dateTime. 

RDF* may the way out (thanks Pierre-Antoine), but for some reason it takes
rather long before it is a Recommendation.

 

Forgive me my stubbornness, but I need to know exactly what's wrong in my
construct.

 

Regards, Hans 

 

From: Mark Wallace <mark.wallace@semanticarts.com> 
Sent: donderdag 25 augustus 2022 23:32
To: hans.teijgeler@quicknet.nl; semantic-web@w3.org
Subject: RE: RDF validity question

 

No. In short,  ranges and domains are for stating things about properties
(Tbox/schema) and not about instances of classes. 

 

If you want to reify the predicate, you could do so using:

1.	rdf:Statement in RDF
2.	owl:Axiom in OWL2,
3.	define your owl owl:Class that will represent the relationship. E.g.
my:HasPartRelation a owl:Class, with possible subclass HasActuatorRelation
or some such. 

 

What is it you want your date/time to indicate?  

 

Very respectfully,

Mark

 

 

From:  <mailto:hans.teijgeler@quicknet.nl> hans.teijgeler@quicknet.nl <
<mailto:hans.teijgeler@quicknet.nl> hans.teijgeler@quicknet.nl> 
Sent: Thursday, August 25, 2022 2:27 PM
To:  <mailto:semantic-web@w3.org> semantic-web@w3.org
Subject: RDF validity question

 

Hi,

 

I am trying to reify predicates in a different way, and I need to know
whether this is valid RDF.

 

Assume I define an rdf:Property:

 

ont:hasPart

    rdf:type owl:ObjectProperty ;

    rdfs:domain rdl:Artefact ; 

    rdfs:range rdl:Artefact .

 

ont:valveHasActuator 

    rdf:type owl:ObjectProperty ;

    rdfs:subPropertyOf ont:hasPart ;

    rdfs:domain rdl:Valve ; 

    rdfs:range rdl:ValveActuator .

 

Then I have project information that tells that individual valve actuator
84128 is a part of individual valve 34543, effective that dateTime.

 

ex:76329

    rdf:type ont:valveHasActuator ;

    rdfs:domain ex:34543 ; # myValve

    rdfs:range ex:84128 ;   # myValveActuator

    meta:effectiveDate "2022-08-24T10:42:00Z"^^xsd:dateTime .

 

Is this semantically and syntactically correct RDF? (it passed the syntactic
test).

 

I hope to hear from you!

 

(sorry Guus, I need the answer asap)