[Attempto] AceWiki - how to get explanation of red?

[Alex Shkotin]

Hi,

If Pellet returns error (well, without explanation;) but only in this case
it is better to say user a truth:
your axiom makes ontology undecidable. try re-formulate or ask support...

actually this kind of situation in practice should be very interesting and
if user insist then it is time for brain storm;)
Alex


2009/7/1 Tobias Kuhn <t.kuhn at gmx.ch>

> Hi,
>
> Right, Pellet can handle TransitiveObjectProperty as long as the
> restrictions are not violated. By the way: my link was outdated and they are
> now called "Global Restrictions on Axioms":
>
>
> http://www.w3.org/TR/owl2-syntax/#Global_Restrictions_on_Axioms_in_OWL_2_DL
>
> However, once the restrictions are violated, Pellet stops running properly
> and returns error messages. What should AceWiki do now? How should it inform
> the users about the problem?
>
> In my view, these global restrictions are too complicated to be explained
> to an average web user.
>
>
> Tobias
>
>
> Alex Shkotin wrote:
>
>> Hi Tobias,
>>  may be it is better to check "Nonstructural Restrictions on Axioms", and
>> disallow TransitiveObjectProperty only in a case of violation.
>> As this kind of reasoning (trans-closure) is one of DL's strong feature.
>> Anyway why not give it to Pellet. I doubt that Pellet ignores
>> TransitiveObjectProperty. Does it?
>>  Alex
>>
>>
>> 2009/7/1 Tobias Kuhn <t.kuhn at gmx.ch <mailto:t.kuhn at gmx.ch>>
>>
>>
>>    Hi,
>>
>>    Blue bullets mean "is used by the reasoner". Red bullets mean "is
>>    not used by the reasoner". The latter is the case for all statements
>>    that cannot be translated into OWL or that would use the OWL
>>    constructs TransitiveObjectProperty or SubObjectPropertyChain. The
>>    problem with these two axiom types is that statements using them can
>>    violate the "Nonstructural Restrictions on Axioms":
>>
>>
>> http://www.w3.org/TR/2008/WD-owl2-syntax-20080411/#Nonstructural_Restrictions_on_Axioms
>>
>>    Since I don't know how to handle these restrictions in a
>>    collaborative environment like a wiki, I simply disallow the axiom
>>    types that are involved.
>>
>>    Thus, the reason why you don't get an answer for questions like
>>    "Which continent contains Oslo?" is that the statement "If X is
>>    located in Y and Y is located in Z then X is located in Z." is
>>    ignored by the reasoner.
>>
>>    If you have an idea how TransitiveObjectProperty and
>>    SubObjectPropertyChain could be supported in a simple way without
>>    the danger to violate these nonstructural restrictions, let me know!
>>
>>
>>    Tobias
>>
>>
>>
>>    George Herson wrote:
>>
>>        I added some sentences to the current Oslo page at
>>        http://attempto.ifi.uzh.ch/webapps/acewikigeo/ and it seems to
>>        me that
>>
>>
>>         Edit...
>>        Add Sentence...
>>        Add Comment...
>>        Delete
>>        Details
>>        Logic
>>           Oslo  is  located in  which  continent ?    (no answer found)
>>        should find an answer since we have
>>
>>
>>         Edit...
>>        Add Sentence...
>>        Add Comment...
>>        Delete
>>        Details
>>        Logic
>>           Norway  is  located in  which  continent ?    -  Europe and rule
>>
>>
>>
>>         Edit...
>>        Add Sentence...
>>        Add Comment...
>>        Delete
>>        Details
>>        Logic
>>           If  X  is  located in  Y  and  Y  is  located in  Z  then  X
>>         is  located in  Z .    So sorry, maybe an expert will be more
>>        helpful.
>>
>>        George
>>        ________________________________
>>        From: Alex Shkotin <alex.shkotin at gmail.com
>>        <mailto:alex.shkotin at gmail.com>>
>>        To: George Herson <gherson at snet.net <mailto:gherson at snet.net>>
>>        Cc: attempto at lists.ifi.uzh.ch <mailto:attempto at lists.ifi.uzh.ch>
>>        Sent: Tuesday, June 30, 2009 2:38:44 PM
>>        Subject: Re: [Attempto] AceWiki - how to get explanation of red?
>>
>>
>>        yes, I need to say vise versa but have a look at
>>        http://clip2net.com/clip/m3050/1246386847-clip-8kb.png
>>         sorry, but after "Which continent is Oslo" there is no
>>        continuation:(
>>
>>
>>        2009/6/30 George Herson <gherson at snet.net <mailto:gherson at snet.net>>
>>
>>
>>
>>        Re: "Which continent is located in Oslo?", try variations on
>>        "Which continent is Oslo located-in?": Oslo is a city, much
>>        smaller than a continent.
>>
>>
>>        George
>>        ________________________________
>>        From: Alex Shkotin <alex.shkotin at gmail.com
>>        <mailto:alex.shkotin at gmail.com>>
>>        To: George Herson <gherson at snet.net <mailto:gherson at snet.net>>
>>        Cc: attempto at lists.ifi.uzh.ch <mailto:attempto at lists.ifi.uzh.ch>
>>        Sent: Tuesday, June 30, 2009 2:20:11 PM
>>        Subject: Re: [Attempto] AceWiki - how to get explanation of red?
>>
>>
>>
>>        Hi George,
>>        then why my question (after rule) is without answer?
>>
>>
>>        2009/6/30 George Herson <gherson at snet.net <mailto:gherson at snet.net>>
>>
>>
>>
>>        Hi Alex,
>>
>>        My guess is that AceWiki bullets are red for rules and blue for
>>        facts.
>>
>>        George
>>        ________________________________
>>        From: Alex Shkotin <alex.shkotin at gmail.com
>>        <mailto:alex.shkotin at gmail.com>>
>>        To: attempto at lists.ifi.uzh.ch <mailto:attempto at lists.ifi.uzh.ch>
>>        Sent: Tuesday, June 30, 2009 12:55:34 PM
>>        Subject: [Attempto] AceWiki - how to get explanation of red?
>>
>>
>>
>>        Hi,
>>        have a look at a picture.
>>        how can I tell that red sentence is definition?
>>        how can I get an explanation  - why the sentence is red?
>>        _______________________________________________
>>        attempto mailing list
>>
>>        attempto at lists.ifi.uzh.ch <mailto:attempto at lists.ifi.uzh.ch>
>>        https://lists.ifi.uzh.ch/listinfo/attempto
>>
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ifi.uzh.ch/pipermail/attempto/attachments/20090701/ae207968/attachment.htm>