Re: Deduced property

Paul, I think Dave's advice is sound: as tempting as it might be, it is 
*not* helpful to talk about OWL subsumption using phrases like 
inheritance. This will do more harm than good (esp. since the 
counter-examples will heavily outweigh the examples).

Hence why the "inheritability" of different OWL features isn't 
documented (and nor should it be).

If you want a non-technical means of introducing the features of OWL, 
examples using IF -- THEN -- (i.e., rules) will give a sound but 
incomplete picture. Studying the rules in OWL 2 RL/RDF is a great 
starting point for anyone wanting to learn a bit about what the *key* 
entailments of the OWL (2) features are (and without having to get into 
the formal semantics):

http://www.w3.org/TR/owl2-profiles/#Reasoning_in_OWL_2_RL_and_RDF_Graphs_using_Rules

The OWL features mean more than what's represented in these rules, but 
IF you can understand these rules, THEN you'll have a working knowledge 
of OWL.

(Unfortunately though, I feel we're fighting a losing battle with 
regards the didactic aspects of OWL in the broader sense of it being a 
*Web standard*. Perhaps the battle is even already lost.)

Best,
Aidan


On 30/01/2014 05:43, PAUL WARREN wrote:
> I have come across this problem recently in some work I have been doing
> investigating people's understanding of OWL constructs.  You can't
> assume that property characteristics are inherited - some are (e.g.
> functionality), some aren't (e.g. transitivity and symmetry).  But I
> have found no reference in any documentation to this fact.
>
> Cheers,
>
> Paul Warren
>
> ------------------------------------------------------------------------
> *From:* Dave Reynolds <dave.e.reynolds@gmail.com>
> *To:* semantic-web@w3.org
> *Sent:* Wednesday, 29 January 2014, 17:05
> *Subject:* Re: Deduced property
>
> OWL, and the underlying logic, are quite different from object oriented
> modelling so using terms like "inheritance" can trip you up. Especially
> when it comes to property axioms.
>
> In the RDF/OWL way of thinking then a property corresponds to set of
> pairs of things that are related by the property. So saying
>
>      :hasParent rdfs:subPropertyOf :hasAncestor
>
> means, and only means, that the set of pairs of things related by
> :hasParent is a subset of the set of pairs of things related by
> :hasAncestor.
>
> It's sets all the way down :)
>
> Dave
>
> On 29/01/14 16:47, Jean-Claude Moissinac wrote:
>  > OK
>  > I really thought that the transitivity was inherited. I will try to find
>  > where and how the non-inheritance is specified
>  > Thank you
>  >
>  > --
>  > Jean-Claude Moissinac
>  >
>  >
>  >
>  > 2014-01-29 Matthew Horridge <matthew.horridge@stanford.edu
> <mailto:matthew.horridge@stanford.edu>
>  > <mailto:matthew.horridge@stanford.edu
> <mailto:matthew.horridge@stanford.edu>>>
>  >
>  >    Hi Jean-Claude,
>  >
>  >    Asserting
>  >
>  >    :hasParent rdfs:subClassOf :hasAncestor
>  >
>  >    and
>  >
>  >    :hasAncestor rdf:type owl:TransitiveProperty
>  >
>  >    does not mean that :hasParent is also transitive.  Transitivity
>  >    isn’t “inherited” down the property hierarchy, so it’s possible to
>  >    have a non-transitive sub property of a transitive super property.
>  >
>  >    Cheers,
>  >
>  >    Matthew
>  >
>  >    On 29 Jan 2014, at 08:30, Jean-Claude Moissinac
>  >    <jean-claude.moissinac@telecom-paristech.fr
> <mailto:jean-claude.moissinac@telecom-paristech.fr>
>  >    <mailto:jean-claude.moissinac@telecom-paristech.fr
> <mailto:jean-claude.moissinac@telecom-paristech.fr>>> wrote:
>  >
>  >>    No, it's not the answer because hasAncestor is transitive and
>  >>    hasParent isn't...
>  >>    (I've a lot of similar situations)
>  >>
>  >>    --
>  >>    Jean-Claude Moissinac
>  >>
>  >>
>  >>
>  >>    2014-01-29 Richard Cyganiak <richard@cyganiak.de
> <mailto:richard@cyganiak.de>
>  >>    <mailto:richard@cyganiak.de <mailto:richard@cyganiak.de>>>
>  >>
>  >>        Jean-Claude,
>  >>
>  >>        You’re looking for this (in Turtle syntax):
>  >>
>  >>          :hasParent rdfs:subClassOf :hasAncestor.
>  >>
>  >>        (Don’t try to read or write RDF/XML directly. You’ll go mad.
>  >>        Use the friendly syntaxes such as Turtle, or graphical tools.)
>  >>
>  >>        Best,
>  >>        Richard
>  >>
>  >>
>  >>        On 29 Jan 2014, at 16:18, Jean-Claude Moissinac
>  >>        <jean-claude.moissinac@telecom-paristech.fr
> <mailto:jean-claude.moissinac@telecom-paristech.fr>
>  >>        <mailto:jean-claude.moissinac@telecom-paristech.fr
> <mailto:jean-claude.moissinac@telecom-paristech.fr>>> wrote:
>  >>
>  >>        > Sorry if my question is very naive, but I'm stuck on this
>  >>        for a while
>  >>        > if I go to examples in the document
>  >> http://www.w3.org/TR/2009/WD-owl2-primer-20090421/
>  >>        > I just want to add the following axiom (expressed here in my
>  >>        syntax)
>  >>        > if
>  >>        > ?s :hasParent  ?f
>  >>        > Then
>  >>        > ?s :hasAncestor ?f
>  >>        >
>  >>        > I've checked a lot of documents and I don't figure how to do
>  >>        it (directly in XML/RDF or interactively with Protégé)
>  >>        >
>  >>        > Thank you in adavnace for your help
>  >>        >
>  >>        > --
>  >>        > Jean-Claude
>  >>        >
>  >>
>  >>
>  >>
>  >
>  >
>
>
>
>

Received on Thursday, 30 January 2014 15:30:12 UTC