Hi Karen,

I have been surprised by how RDF and reasoning combine, and hopefully I now know enough to give a "reasonable" answer.

Looking at the role contributor, it is asserted to be a subproperty of dc:contributor (from the DC Elements, not the Terms). It is also asserted to be an OWL ObjectProperty. Finally there is an assertion that contributor is a BIBFRAME Role.

You are correct that these assertions combine with AND. They are "just" assertions and whether there is an inconsistency or error depends on what (kind of) logic and other knowledge you use.

For a long time I assumed that something could not be a SKOS Concept and an RDFS Property, but SKOS does not impose such a limitation. So even if it feels wrong, I think a relator may be a rdfs:Property (implied by rdfs:subPropertyOf and owl:ObjectProperty) and a bf:Role.

When you use http://id.loc.gov/vocabulary/relators/ctb as a predicate and the object in the triple is a literal (such as a string), I think an OWL reasoner may find an inconsistency: owl:ObjectProperty implies that the object should be an individual, which a literal is not. However, without testing this, a reasoner may also infer that there is another individual that it doesn't know of. That is the open world assumption that makes OWL less suitable (or harder to use) as a constraint language.

Without looking into the BIBFRAME model, I think bf:Role is the class of "things" that can qualify how agents are involved in activities (similar to how the Provenance Ontology uses Role<https://www.w3.org/TR/2013/NOTE-prov-primer-20130430/#roles> to link activities to entities and activities and agents).

I hope this helps!

Regards,

Ben
Ben Companjen
Research Software and Data Engineer / Digital Scholarship Librarian
Centre for Digital Scholarship
Leiden University Libraries (UBL)

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From: Code for Libraries <[log in to unmask]> on behalf of Karen Coyle <[log in to unmask]>
Date: Monday, 9 October 2023 at 23:36
To: [log in to unmask] <[log in to unmask]>
Subject: [CODE4LIB] Question about multiple declarations
All,

I am looking at the LoC relators at id.loc.gov, and am trying to
understand the implications of the multiple declarations for relator terms.

<rdfs:subPropertyOf
rdf:resource="https://eur03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpurl.org%2Fdc%2Felements%2F1.1%2Fcontributor%2522%2F&data=05%7C01%7Cb.a.companjen%40LIBRARY.LEIDENUNIV.NL%7C401c41924b284606a8a308dbc90fca8b%7Cca2a7f76dbd74ec091086b3d524fb7c8%7C0%7C0%7C638324841896567069%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Oq7kbkRMlOTj9PV2ad5LvC%2Fc0pAAQIHdZ3yzntmZQEU%3D&reserved=0<http://purl.org/dc/elements/1.1/contributor%22/>>
<rdf:type rdf:resource="https://eur03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23ObjectProperty%2522%2F&data=05%7C01%7Cb.a.companjen%40LIBRARY.LEIDENUNIV.NL%7C401c41924b284606a8a308dbc90fca8b%7Cca2a7f76dbd74ec091086b3d524fb7c8%7C0%7C0%7C638324841896567069%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=ihZdG%2FAhEV559bwlXHatGmu4ajLElokdV0Yhc9DQ0k0%3D&reserved=0<http://www.w3.org/2002/07/owl#ObjectProperty%22/>>
<rdf:type rdf:resource="https://eur03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fid.loc.gov%2Fontologies%2Fbibframe%2FRole%2522%2F&data=05%7C01%7Cb.a.companjen%40LIBRARY.LEIDENUNIV.NL%7C401c41924b284606a8a308dbc90fca8b%7Cca2a7f76dbd74ec091086b3d524fb7c8%7C0%7C0%7C638324841896567069%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=g%2B8punPd1L3pZMQqU0mjU6%2FZ%2Br6PCq0c1W22Fuyyww4%3D&reserved=0<http://id.loc.gov/ontologies/bibframe/Role%22/>>

dct:contributor is not an Object Property; there is no object type
given, so I suppose it is de facto an Annotation Property. I read the
next statement as narrowing, so at statement 2 we have:
   subproperty of dct:contributor AND an owl:ObjectProperty

If my reading is correct, it would be a violation of this to use the
relator with a string rather than a thing.

(Stop me here if I'm wrong.)

Then the 3rd statement appears to say that the relator is a bf:Role,
which is a BIBFRAME-specific class. I can't wrap my head around the
functionality of this statement and would love a brief explanation. I'm
undoubtedly not into BIBFRAME deep enough to grok this.

Also, my reading is that each relator is ALL THREE OF THESE; this is an
AND not at OR. Right?

Thanks for any help,
kc

--
Karen Coyle
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