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Re: [oslc-core] Use of oslc:Property to define usage of rdf:type?

From
Nick Crossley <>
Date
2015-08-05T15:05:56+00:00
ID
Thread
Re: [oslc-core] Use of oslc:Property to define usage of rdf:type?
Ian,

I do not see the two examples you give as really contradictory. In both my rdf:type case and your oslc_rm:uses case, the oslc:Property property describes certain aspects of all occurrences of a property - it indicates the possible number of occurrences of the property, the type, range, and representation of the values of the property, etc. In human-readable text, we describe the intended use of the property, and may place further constraints on it. The only difference is that in my rdf:type case, I place an additional constraint on one of the possibly many occurrences.

Suppose I have a wallet, and I want to describe constraints on its contents: the contents must be US bills only. But because I need the owner to pay for a bus ride, I require that two of the possibly many bills must be one dollar bills (ignoring here the case of the rare $2 bill). I see nothing wrong in adding that extra qualification in the descriptive text for a shape - I do not believe such text is information that "a machine would read and act upon". Where we have non-text forms for the constraints, I would agree that more precision is needed.

Nick.

Ian Green1 ---08/05/2015 01:41:18 AM---Hi Nick It is not the clarity of the language.  That seems perfectly clear to me.

From:	Ian Green1 <>

To:	Nick Crossley/Irvine/IBM@IBMUS

Cc:	Martin P Pain <>, OASIS () <>

Date:	08/05/2015 01:41 AM

Subject:	Re: [oslc-core] Use of oslc:Property to define usage of rdf:type?

Sent by:	<>

Hi Nick 

It is not the clarity of the language.  That seems perfectly clear to me.   My question is about the meaning setting aside the prose - the bits a machine would read and act upon. 

I don't see a problem in defining the usage of rdf:type - nothing special about that property.  What is troubling me is that rdf:type is multi-valued, yet the oslc:Property does not seem to have the meaning "at least one of the rdf:type values should be such and such". 

In contrast, the (intended) meaning of the oslc_rm:uses property, which is zero or many, is that each and every occurrence is uniformly described by the oslc:Property. 

So there are two different interpretations, both in use.  Which one is correct, and how should the other case be expressed? 

best wishes,

   -ian

 (Ian Green1/UK/IBM@IBMGB)

IBM 

Nick Crossley <> wrote on 04/08/2015 17:05:26:

> From: Nick Crossley <> 

> To: Ian Green1/UK/IBM@IBMGB 

> Cc: Martin P Pain/UK/IBM@IBMGB, OASIS (-

> open.org) <> 

> Date: 04/08/2015 17:12 

> Subject: Re: [oslc-core] Use of oslc:Property to define usage of rdf:type? 

> 

> Ian,

> 

> I would have thought that my language "A resource type URI. An 

> Activity MUST have a resource type of <code>oslc_config:Activity</

> code>,  and MAY have other types" does not really need any special 

> interpretation - it seems very explicit to me. My text replaced the 

> phrase used in several other OSLC 3 draft specs, including change 

> management, which says "The resource type URIs. One of at least has 

> the value of <code>http://open-services.net/ns/cm#ChangeRequest</code>.

> " The latter is of course not grammatically correct.

> 

> The W3C LDP spec uses this explanation: "The representation of a 

> LDPC MAY have an rdf:type of ldp:Container for Linked Data Platform 

> Container. Non-normative note: LDPCs might have additional types, 

> like any LDP-RS." Would you prefer the OSLC shapes used this phrase 

> (with MUST rather than MAY where appropriate)?

> 

> Or is your question more fundamental - do you think that the OSLC 

> Shape, using oslc:Property resources, should not include any mention

> of rdf:type? If so, given that our specs now generate the resource 

> description tables from shapes, where would we put descriptions of 

> the requirements on rdf:type? Why would type be treated differently 

> from any other property that might have similar semantics - one 

> value defined by the standard, others possible for provider-specific

> extensions?

> 

> Nick.

> 

> [image removed] Ian Green1 ---08/04/2015 08:04:41 AM---I should have

> put my question differently.  Where is it defined that  Nick's 

> interpretation/usage of

> 

> From: Ian Green1 <>

> To: Martin P Pain <>

> Cc: Nick Crossley/Irvine/IBM@IBMUS, OASIS (-

> open.org) <>

> Date: 08/04/2015 08:04 AM

> Subject: Re: [oslc-core] Use of oslc:Property to define usage of rdf:type?

> 

> 

> 

> I should have put my question differently.  Where is it defined that

> Nick's interpretation/usage of oslc:Property is the one he intends? 

> 

> 

> best wishes,

>   -ian

> 

>  (Ian Green1/UK/IBM@IBMGB)

> IBM 

> 

> <> wrote on 04/08/2015 13:08:55:

> 

> > From: Martin P Pain/UK/IBM@IBMGB 

> > To: Ian Green1/UK/IBM@IBMGB 

> > Cc: Nick Crossley <>, OASIS (oslc-

> > ) <> 

> > Date: 04/08/2015 13:09 

> > Subject: Re: [oslc-core] Use of oslc:Property to define usage of rdf:type? 

> > Sent by: <> 

> > 

> > If it's zero-or-many or one-or-many how often would you need to 

> > constrain all values? 

> > the *-or-many occurs values are the main point of extensibility - if

> > the client doesn't understand all values (because others are 

> > extensions), it can doits best with the ones that it does understand. 

> > I expect there are times when you would need to - for example a 

> > server advertising its own resource shapes that can't handle 

> > unrecognised values (i.e. doesn't store everything it receives in a 

> > triple store), but for use in the specs I expect leaving it open 

> > would be the default. 

> > 

> > Just my thoughts...

> > 

> 

> > 

> > 

> > 

> > Martin Pain

> > Software Developer - Green Hat

> > Rational Test Virtualization Server, Rational Test Control Panel 

> > 

> > Phone: +44 (0)1962 815317 | Tie-Line: 37245317

> > E-mail: 

> > Find me on: [image removed]  and within IBM on: [image removed]   

> > 

> > [image removed] 

> > 

> > 

> > 

> > 

> > IBM United Kingdom Limited Registered in England and Wales with 

> > number 741598 Registered office: PO Box 41, North Harbour, 

> > Portsmouth, Hants. PO6 3AU 

> > 

> > 

> > 

> > From:        Ian Green1/UK/IBM@IBMGB 

> > To:        Nick Crossley <> 

> > Cc:        OASIS () <oslc-

> > > 

> > Date:        04/08/2015 13:04 

> > Subject:        Re: [oslc-core] Use of oslc:Property to define usage

> > of rdf:type? 

> > Sent by:        <> 

> > 

> > 

> > 

> > I've not noticed it being used with this interpretation.  So how 

> > would one define a Property which covered all occurrences of a 

> > multi-valued property? 

> > 

> > 

> > 

> > 

> > best wishes,

> >   -ian

> > 

> >  (Ian Green1/UK/IBM@IBMGB)

> > IBM 

> > 

> > <> wrote on 30/07/2015 14:43:06:

> > 

> > > From: Nick Crossley <> 

> > > To: Ian Green1/UK/IBM@IBMGB 

> > > Cc: OASIS () <oslc-

> >

> > > Date: 30/07/2015 14:43 

> > > Subject: Re: [oslc-core] Use of oslc:Property to define usage ofrdf:type? 

> > > Sent by: <> 

> > > 

> > > Ian wrote: 

> > > 

> > > In https://tools.oasis-open.org/version-control/browse/wsvn/oslc-

> > > ccm/trunk/specs/config-mgt/activity-shapes.ttl the rdf:type of and 

> > > oslc:Activity is described: 

> > > 

> > > <#acttype> 

> > >    a                        oslc:Property ; 

> > >    oslc:name                "type" ; 

> > >    oslc:propertyDefinition  rdf:type ; 

> > >    oslc:occurs              oslc:One-or-many ; 

> > >    oslc:readOnly            true ; 

> > >    oslc:representation      oslc:Reference ; 

> > >    oslc:valueType           oslc:Resource ; 

> > >    dcterms:description      """A resource type URI. An Activity MUST

> > > have a resource type of <code>oslc_config:Activity</code>, 

> > > and MAY have other types."""^^rdf:XMLLiteral . 

> > > 

> > > rdf:type is multi-valued but the description made by <#actype> is 

> > > particular to exactly one of those values, not all of them (I assume

> > > that is the intention). 

> > > Yes, that is the intention. It is common for OSLC shapes to define 

> > > one or more of the required rdf:type values but leave it open for 

> > > others to be applied.

> > > 

> > > Nick. 

> > Unless stated otherwise above:

> > IBM United Kingdom Limited - Registered in England and Wales with 

> > number 741598. 

> > Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU 

> > 

> > Unless stated otherwise above:

> > IBM United Kingdom Limited - Registered in England and Wales with 

> > number 741598. 

> > Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

> Unless stated otherwise above:

> IBM United Kingdom Limited - Registered in England and Wales with 

> number 741598. 

> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

Unless stated otherwise above:

IBM United Kingdom Limited - Registered in England and Wales with number 741598. 

Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
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