<div dir="ltr"><div><div>I don't know what I have done wrong.<br><br>I tried using the web interface for race, but don't know why (below) subset #1 (Mary) and set#2 (at least 1 woman) are included.<br><br>I had the axiom set:<br><br>Every man is a human. Every woman is a human. <br>Mary is a human that is a woman. John is a human that is a man. Mack is a human.<br>if a human is not provably a woman then the human is a man.<br><br></div>I had the query:<br><br>Who is a man and is a human?<br><br></div>RACE said: overall time: 0.552 sec; RACE time: 0.04 sec<div class="in"><p><b>Axioms</b>: Every man is a human. Every woman is a human. Mary is a human that is a woman. John is a human that is a man. Mack is a human. if a human is not provably a woman then the human is a man.</p><p><b>Query</b>: Who is a man and is a human?</p><p><b>Parameters</b>: </p></div><p>The following minimal subsets of the axioms answer the query:</p><ul><li>Subset 1<ul><li>3: Mary is a human that is a woman.</li><li>6: If a human is not provably a woman then the human is a man.</li><li>Substitution: who = (at least 1) woman</li></ul></li><li>Subset 2<ul><li>3: Mary is a human that is a woman.</li><li>6: If a human is not provably a woman then the human is a man.</li><li>Substitution: who = Mary</li></ul></li><li>Subset 3<ul><li>4: John is a human that is a man.</li><li>Substitution: who = John</li></ul></li><li>Subset 4<ul><li>5: Mack is a human.</li><li>6: If a human is not provably a woman then the human is a man.</li><li>Substitution: who = Mack</li></ul></li></ul><br>I thought maybe I needed to say "man is a human" and "woman is a human" can't occur at the same time (or at least is abnormal) to exclude Subset #1 and Subset #2, but instead I get a syntax error:<br><br>Axiom Set:<br>Every man is a human. Every woman is a human. <br>Mary is a human that is a woman. John is a human that is a man. Mack is a human.<br>if a human is not provably a woman and the human is not provably a man then the human is a man.<br>if a human is provably a woman and the human is provably a man then it is abnormal. <br>if a human is provably a man then the human is not a woman.<br>if a human is provably a woman then the human is not a man.<br><br>ImportanceTypeSentenceProblemDescription/Suggestion<br><br>errorraceAxioms cannot be parsed.<br><br>Correct the axioms.errorsentence7if a human is provably <> a woman and the human is provably a man then it is abnormal.<br><br>This is the first sentence that was not ACE. The sign <> indicates the position where parsing failed.warningword5MackUndefined word. Interpreted as a singular proper name.<br><br><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Aug 11, 2015 at 4:32 AM, Norbert E. Fuchs <span dir="ltr"><<a href="mailto:fuchs@ifi.uzh.ch" target="_blank">fuchs@ifi.uzh.ch</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div><div><br></div><div><div dir="ltr">On Tuesday, 26 May 2015 14:28:46 UTC+2, Norbert E. Fuchs wrote:<blockquote class="gmail_quote" style="margin:0;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex"> <br>> On 25 May 2015, at 11:18 , Norbert E. Fuchs <<a rel="nofollow">fu...@ifi.uzh.ch</a>> wrote: <br>> <br>> ... I tried – but until now was not completely successful – to get default reasoning with the help of modality ... <br><br></blockquote><div><br></div><div>Well, modality obviously is not the way to go since it does not actually implement non-monotonicity. </div><div><br></div><div>In the meantime I extended my reasoner RACE [1] for Attempto Controlled English ACE by non-monotonic reasoning based on the standard combination of strong negation (logical negation) and weak negation (negation as failure) both of which are offered by ACE, and have been previously used in Tobias Kuhn's AceRules [2]. </div><div><br></div><div>Here is an example demonstrating what I have achieved so far. </div><div><br></div><div> <i>Axioms:</i> </div><div> Beaky is a bird that flies. </div><div> Tweety is a bird. </div><div> If a bird is abnormal then it does not fly. </div><div> If a bird is sick then it is abnormal. </div><div> If a bird does not provably fly then it is abnormal.</div><div><br></div><div> <i>Query:</i> </div><div> Which bird does not fly?</div><div><br></div><div>The proof succeeds and provides the following report:</div><div><br></div><div> The following minimal subset of the axioms answer the query:</div><div><br></div><div> 2: Tweety is a bird.</div><div> 3: If a bird is abnormal then it does not fly.</div><div> 5: If a bird does not provably fly then it is abnormal.</div><div> Substitution: which = Tweety</div><div><br></div><div>Notice that my implementation restricts the use of weak negation to the preconditions of if-then sentences – which seems reasonable. Further notice that the syntax of weak negation (... does/do/is/are not provably ..., ... it is not provable that ...) explicitly indicates the possibility of non-monotonic reasoning. </div><div><br></div><div><br></div><div>I'd appreciate your comments. Feel free to experiment with my implementation via RACE's web-interface [1].</div><div><br></div><div><br></div><div>[1] <a href="http://attempto.ifi.uzh.ch/race/" target="_blank">http://attempto.ifi.uzh.ch/race/</a></div><div><br></div><div>[2] <a href="http://attempto.ifi.uzh.ch/site/resources/" target="_blank">http://attempto.ifi.uzh.ch/site/resources/</a></div></div></div></div><br></div><br>_______________________________________________<br> attempto mailing list<br> <a href="mailto:attempto@lists.ifi.uzh.ch">attempto@lists.ifi.uzh.ch</a><br> <a href="https://lists.ifi.uzh.ch/listinfo/attempto" rel="noreferrer" target="_blank">https://lists.ifi.uzh.ch/listinfo/attempto</a><br> <br></blockquote></div><br></div>