domainIncludes and rangeIncludes

Hi Dan

Great to see the things moving forward to clarify those points we have
discussed for quite a while :)
Semantics of domainIncludes and rangeIncludes are quite clearly explained
"for humans" in the wiki page, but seems to me some formal clarification
should be added, even if it's lighter than RDFS.

1. Subsumption and inheritance : Let's assume the hierarchy of
schema.orgtypes/classes will continue to use rdfs:subClassOf until
some logic guru
forbids it. This entails that schema.org classes are RDFS classes by RDFS
declared semantics. Are domainIncludes and rangeIncludes inherited by
subclasses, IOW do the following rules hold ? Seems implicit in the
structure of schema.org pages.

(p  schema:domainIncludes  D1) AND  (D2  rdfs:subClassOf   D1) => ((p
schema:domainIncludes  D2)
(p  schema:rangeIncludes  R1) AND  (R2  rdfs:subClassOf   R1) => (p
schema:rangeIncludes  R2)

2. In the current state of schema.org pages, the rangeIncludes assertions
are declared for each class using the property (IOW for value of
domainIncludes), but actually the values of rangeIncludes are global if we
trust the RDFa declarations, which means they are the same for all classes
in the domainIncludes, there is no such thing as local restriction for
rangeIncludes. And it seems that in the pages

If those rules hold, it would be good to see them expressed formally
somewhere.

And BTW when do you think the RDFa page is about to use the new property
names?

Bernard


2012/11/30 Dan Brickley <danbri@google.com>

> Hi folks
>
> 3. Class/Property
>
> There are several cases (including the above-mentioned Actions draft)
> where it is useful within schema.org to have a first class type
> representing the notion of 'Class', and of 'Property'. This is rather
> meta and while it is not something designed for mainstream webmasters
> to encounter, it will help with structuring and documenting the
> vocabulary.
>
> I have written up a proposal for adding these (and aliasing them to
> rdfs:Class, rdf:Property) at
> http://www.w3.org/wiki/WebSchemas/SchemaDotOrgMetaSchema  ...alongside
> a proposal to use schema.org/domainIncludes and
> schema.org/rangeIncludes in our RDFa representation of the schema.
>
>
> Comments on any / all of the above are welcomed; ideally in the
> WebSchemas area of the W3C wiki or here on public-vocabs. If you reply
> by mail please adjust the Subject line to match your topic...
>
> cheers,
>
> Dan
>
>


-- 
*Bernard Vatant
*
Vocabularies & Data Engineering
Tel :  + 33 (0)9 71 48 84 59
 Skype : bernard.vatant
Blog : the wheel and the hub <http://blog.hubjects.com/>

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