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HydraCG / Specifications

Specifications created by the Hydra W3C Community Group
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Specify the expected cardinality of properties (using OWL) #35

Open lanthaler opened 10 years ago

lanthaler commented 10 years ago

Since the hint about the expected cardinality of a property is being lost if they are being turned into singulars (#25), it would make sense to specifiy it using OWL.

RubenVerborgh commented 10 years ago

I will have a look at this.

akuckartz commented 10 years ago

+1

RubenVerborgh commented 10 years ago

I have investigated and I don't think there is a way in OWL to express maximum cardinality. Essentially, if there is no maxCardinality (which is always an integer), it is unbounded.

I thus propose to close this issue.

lanthaler commented 10 years ago

What about http://www.w3.org/TR/owl2-syntax/#Maximum_Cardinality?

RubenVerborgh commented 10 years ago

What about http://www.w3.org/TR/owl2-syntax/#Maximum_Cardinality?

It says:

A maximum cardinality expression ObjectMaxCardinality( n OPE CE ) consists of a nonnegative integer n

But our n is not an integer, so there's nothing we can do.

lanthaler commented 10 years ago

Oh, OK. You are of course right. I think we should do this nevertheless—even if it’s just in prose in the spec or rdfs:comment or something. I slightly tweaked the title of the issue to reflect this.

RubenVerborgh commented 10 years ago

Okay; I've removed myself as assignee for now because it doesn't involve OWL, but of course willing to take this up later.

lanthaler commented 10 years ago

PROPOSAL: This is mostly for developers and not directly for machines (apart from validators). Our needs are quite trivial so I would suggest to simply define something like hydra:multiple that we can use both in SupportedProperty and in the vocabulary description.