<div>Hi,</div> <div> </div> <div>If Pellet returns error (well, without explanation;) but only in this case it is better to say user a truth: </div> <div>your axiom makes ontology undecidable. try re-formulate or ask support...</div> <div> </div> <div>actually this kind of situation in practice should be very interesting and if user insist then it is time for brain storm;)<br></div> <div>Alex</div> <div><br> </div> <div class="gmail_quote">2009/7/1 Tobias Kuhn <span dir="ltr"><<a href="mailto:t.kuhn@gmx.ch">t.kuhn@gmx.ch</a>></span><br> <blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote">Hi,<br><br>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 By the way: my link was outdated and they are now called "Global Restrictions on Axioms":<br> <br> <a href="http://www.w3.org/TR/owl2-syntax/#Global_Restrictions_on_Axioms_in_OWL_2_DL" target="_blank">http://www.w3.org/TR/owl2-syntax/#Global_Restrictions_on_Axioms_in_OWL_2_DL</a><br><br>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?<br> <br>In my view, these global restrictions are too complicated to be explained to an average web user.<br><br><br>Tobias<br><br><br>Alex Shkotin wrote:<br> <blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote"> <div class="im">Hi Tobias,<br> may be it is better to check "Nonstructural Restrictions on Axioms", and disallow TransitiveObjectProperty only in a case of violation.<br>As this kind of reasoning (trans-closure) is one of DL's strong feature.<br> Anyway why not give it to Pellet. I doubt that Pellet ignores TransitiveObjectProperty. Does it?<br> Alex<br><br><br></div>2009/7/1 Tobias Kuhn <<a href="mailto:t.kuhn@gmx.ch" target="_blank">t.kuhn@gmx.ch</a> <mailto:<a href="mailto:t.kuhn@gmx.ch" target="_blank">t.kuhn@gmx.ch</a>>> <div> <div></div> <div class="h5"><br><br> Hi,<br><br> Blue bullets mean "is used by the reasoner". Red bullets mean "is<br> not used by the reasoner". The latter is the case for all statements<br> that cannot be translated into OWL or that would use the OWL<br> constructs TransitiveObjectProperty or SubObjectPropertyChain. The<br> problem with these two axiom types is that statements using them can<br> violate the "Nonstructural Restrictions on Axioms":<br><br> <a href="http://www.w3.org/TR/2008/WD-owl2-syntax-20080411/#Nonstructural_Restrictions_on_Axioms" target="_blank">http://www.w3.org/TR/2008/WD-owl2-syntax-20080411/#Nonstructural_Restrictions_on_Axioms</a><br> <br> Since I don't know how to handle these restrictions in a<br> collaborative environment like a wiki, I simply disallow the axiom<br> types that are involved.<br><br> Thus, the reason why you don't get an answer for questions like<br> "Which continent contains Oslo?" is that the statement "If X is<br> located in Y and Y is located in Z then X is located in Z." is<br> ignored by the reasoner.<br><br> If you have an idea how TransitiveObjectProperty and<br> SubObjectPropertyChain could be supported in a simple way without<br> the danger to violate these nonstructural restrictions, let me know!<br><br><br> Tobias<br><br><br><br> George Herson wrote:<br><br> I added some sentences to the current Oslo page at<br> <a href="http://attempto.ifi.uzh.ch/webapps/acewikigeo/" target="_blank">http://attempto.ifi.uzh.ch/webapps/acewikigeo/</a> and it seems to<br> me that<br><br><br> Edit...<br> Add Sentence...<br> Add Comment...<br> Delete<br> Details<br> Logic<br> Oslo is located in which continent ? (no answer found)<br> should find an answer since we have<br><br><br> Edit...<br> Add Sentence...<br> Add Comment...<br> Delete<br> Details<br> Logic<br> Norway is located in which continent ? - Europe and rule<br><br><br><br> Edit...<br> Add Sentence...<br> Add Comment...<br> Delete<br> Details<br> Logic<br> If X is located in Y and Y is located in Z then X<br> is located in Z . So sorry, maybe an expert will be more<br> helpful.<br><br> George<br> ________________________________<br> From: Alex Shkotin <<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a><br></div></div> <mailto:<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a>>><br> To: George Herson <<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a> <mailto:<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a>>><br> Cc: <a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a> <mailto:<a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a>> <div class="im"><br> Sent: Tuesday, June 30, 2009 2:38:44 PM<br> Subject: Re: [Attempto] AceWiki - how to get explanation of red?<br><br><br> yes, I need to say vise versa but have a look at<br> <a href="http://clip2net.com/clip/m3050/1246386847-clip-8kb.png" target="_blank">http://clip2net.com/clip/m3050/1246386847-clip-8kb.png</a><br> sorry, but after "Which continent is Oslo" there is no<br> continuation:(<br><br><br></div> 2009/6/30 George Herson <<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a> <mailto:<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a>>> <div class="im"><br><br><br> Re: "Which continent is located in Oslo?", try variations on<br> "Which continent is Oslo located-in?": Oslo is a city, much<br> smaller than a continent.<br> <br><br> George<br> ________________________________<br> From: Alex Shkotin <<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a><br></div> <mailto:<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a>>><br> To: George Herson <<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a> <mailto:<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a>>><br> Cc: <a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a> <mailto:<a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a>> <div class="im"><br> Sent: Tuesday, June 30, 2009 2:20:11 PM<br> Subject: Re: [Attempto] AceWiki - how to get explanation of red?<br><br><br><br> Hi George,<br> then why my question (after rule) is without answer?<br> <br><br></div> 2009/6/30 George Herson <<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a> <mailto:<a href="mailto:gherson@snet.net" target="_blank">gherson@snet.net</a>>> <div class="im"><br><br><br> Hi Alex,<br><br> My guess is that AceWiki bullets are red for rules and blue for<br> facts.<br><br> George<br> ________________________________<br> From: Alex Shkotin <<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a><br> </div> <mailto:<a href="mailto:alex.shkotin@gmail.com" target="_blank">alex.shkotin@gmail.com</a>>><br> To: <a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a> <mailto:<a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a>> <div class="im"><br> Sent: Tuesday, June 30, 2009 12:55:34 PM<br> Subject: [Attempto] AceWiki - how to get explanation of red?<br><br><br><br> Hi,<br> have a look at a picture.<br> how can I tell that red sentence is definition?<br> how can I get an explanation - why the sentence is red?<br> _______________________________________________<br> attempto mailing list<br><br></div> <a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a> <mailto:<a href="mailto:attempto@lists.ifi.uzh.ch" target="_blank">attempto@lists.ifi.uzh.ch</a>> <div class="im"><br> <a href="https://lists.ifi.uzh.ch/listinfo/attempto" target="_blank">https://lists.ifi.uzh.ch/listinfo/attempto</a><br><br><br></div></blockquote></blockquote></div><br>