Hi Lorenz and Dave, Thanks for the explanation! I did not realize the difference between equivalence and subclassof in this context.
Maybe this is also the solution to this question? Change the subclassof to an equivalence? Since both resources: <http://wordnet-rdf.princeton.edu/wn31/%27s+Gravenhage-n> <http://wordnet-rdf.princeton.edu/wn31/%27hood-n> would fall inside the :LexicalEntryNoun class and show up in his SPARQL query. Or am I missing something again? Regards, Barry -----Original Message----- From: Lorenz Buehmann [mailto:buehm...@informatik.uni-leipzig.de] Sent: dinsdag 12 december 2017 19:01 To: users@jena.apache.org Subject: Re: OWL reasoner not making deduction for class with value restriction Hi Barry, On 12.12.2017 18:43, Nouwt, B. (Barry) wrote: > Hi Lorenz, > > You say: > > "if some individual :x belongs to class :LexicalEntryNoun, then a > triple > > :x wn:part_of_speech wn:noun . > > can be inferred." > > , but isn't it also the other way around? > > "if some individual :x has the property wn:part_of_speech wn:noun, > then a triple > > :x rdfs:type LexicalEntryNoun > > can be inferred." No, why do you think so? It's a SubClassOf axiom and the class LexicalEntryNoun is on the left-hand side (in Manchester OWL syntax to make it more readable): Class: LexicalEntryNoun SubClassOf: wn:part_of_speech value wn:noun OWL is based on Description Logics, the semantics is defined on set theory: :A rdfs:subClassOf :B implies the set of individuals in :A is a subset of the set of individuals in :B. Or just see it as logical implication, "if A then B" Having also the other direction of inference would need an EquivalentClass axiom, i.e. one has to use owl:equivalentClass instead of rdfs:subClassOf: :LexicalEntryNoun a owl:Class ; owl:equivalentClass [ a owl:Restriction ; owl:onProperty wn:part_of_speech ; owl:hasValue wn:noun ] . This means both class expressions contain exactly the same set of individuals. Indeed, as you probably already recognized, this is just "syntactic sugar" for two rdfs:subClassOf axioms for both directions. Hope this answer helps, if not, feel free to ask. Cheers, Lorenz > > Regards, Barry > > > > -----Original Message----- > From: Lorenz Buehmann [mailto:buehm...@informatik.uni-leipzig.de] > Sent: dinsdag 12 december 2017 16:15 > To: users@jena.apache.org > Subject: Re: OWL reasoner not making deduction for class with value > restriction > > Good evening! > > > I commented already on StackOverflow, but to make it consistent with the > mailing list here, please read the comments inline: > > > On 12.12.2017 15:55, Andrew U. Frank wrote: >> I have asked on stackoverflow, perhaps somebody here knows the answer >> >> >> >> I try to add a bit of ontology to a (public) RDF dataset (wordnet), >> specifically I need to differentiate between |LexicalEntries| for >> Verbs and Nouns, separated as two subclasses. Following examples on >> the web and in the OWL standard, I assumed that >> >> |:LexicalEntryNoun a owl:Class ; rdfs:subClassOf [ a owl:Restriction >> |; >> owl:onProperty wn:part_of_speech ; owl:hasValue wn:noun ] . | >> >> should build a class |LexicalEntryNoun|, but the query (in jena >> fuseki) > What means "build a class"? This axiom states that > > if some individual :x belongs to class :LexicalEntryNoun, then a > triple > > :x wn:part_of_speech wn:noun . > > can be inferred. > >> |prefix : <http://gerastree.at/2017/litonto#> SELECT * WHERE { ?s a >> :LexicalEntryNoun. } | >> >> gives an empty result. The two URI which should be returned are >> included in the class represented by a blank node, which stands for >> the restriction, but are not reported as |LexicalEntryNoun| as >> reported in other queries. > Your query is just looking for subjects of RDF triples that belong to > class :LexicalEntryNoun, i.e. that match the pattern > > ?s rdf:type :LexicalEntryNoun . > > Neither your data nor the axiom above is "generating" such an individual, at > least not by OWL inference. > > Does this answer your question? > > > Lorenz > >> i am new to OWL and do not find many examples of OWL in turtle syntax. >> Where is my error? Thank you for help! >> >> I constructed a very small subset of data which is loaded together >> with the OWL reasoner |http://jena.hpl.hp.com/2003/OWLFBRuleReasoner|: >> >> |@prefix wn31: <http://wordnet-rdf.princeton.edu/wn31> . @prefix >> lemon: <http://lemon-model.net/lemon#> . @prefix nlp: >> <http://gerastree.at/nlp_2015#> . @prefix rdf: >> <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix lit: >> <http://gerastree.at/lit_2014#> . @prefix wn: >> <http://wordnet-rdf.princeton.edu/ontology#> . @prefix rdfs: >> <http://www.w3.org/2000/01/rdf-schema#> . @prefix ns: >> <http://www.example.org/ns#> . @prefix owl: >> <http://www.w3.org/2002/07/owl#> . @prefix xsd: >> <http://www.w3.org/2001/XMLSchema#> . @prefix : >> <http://gerastree.at/2017/litonto#> . >> <http://wordnet-rdf.princeton.edu/wn31/%27s+Gravenhage-n> a _:b0 , >> owl:Thing , rdfs:Resource , lemon:LexicalEntry ; lemon:canonicalForm >> <http://wordnet-rdf.princeton.edu/wn31/%27s+Gravenhage-n#CanonicalFor >> m >> ; lemon:sense >> <http://www.lexvo.org/page/wordnet/30/noun/%27s_gravenhage_1_15_00> , >> <http://wordnet-rdf.princeton.edu/wn31/%27s+Gravenhage-n#1-n> ; >> wn:part_of_speech wn:noun ; owl:sameAs >> <http://wordnet-rdf.princeton.edu/wn31/%27s+Gravenhage-n> . >> <http://wordnet-rdf.princeton.edu/wn31/%27hood-n> a _:b0 , owl:Thing >> , rdfs:Resource , lemon:LexicalEntry ; lemon:canonicalForm >> <http://wordnet-rdf.princeton.edu/wn31/%27hood-n#CanonicalForm> ; >> lemon:sense >> <http://www.lexvo.org/page/wordnet/30/noun/%27hood_1_15_00> , >> <http://wordnet-rdf.princeton.edu/wn31/%27hood-n#1-n> ; >> wn:part_of_speech wn:noun ; owl:sameAs >> <http://wordnet-rdf.princeton.edu/wn31/%27hood-n> . :LexicalEntryNoun >> a owl:Class ; rdfs:subClassOf [ a owl:Restriction ; owl:onProperty >> wn:part_of_speech ; owl:hasValue wn:noun ] . | >> > This message may contain information that is not intended for you. 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