thank you barry! your explanation did the trick. (1) it works and (2) i
understand it (perhaps more important).
:LexicalEntryNoun a owl:Class ;
owl:equivalentClass # not: rdfs:subClassOf
[ a owl:Restriction ;
owl:onProperty wn:part_of_speech ;
owl:hasValue wn:noun
] .
i think that some explanation which i found on the web and copied dealt
with the issue that there were more things which satisfied the
restriction and thus the newly defined class was a subset of these (and
somewhere else in the example, the new class was defined, which i did
not notice).
thank you all to clarify the point!
to barry: do you want the honor to add the solution to stackoverflow? i
will then confirm it.
andrew
On 12/12/2017 01:12 PM, Nouwt, B. (Barry) wrote:
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 ] . |
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