Is it possible to infer new knowledge about an ontology only from a query in SPARQL?

[Manuel Enrique Puebla Martinez]

 Hello:

Is it possible to infer new knowledge about an ontology only from a query in 
SPARQL?

I have a question about the use of the SPARQL language about ontologies. So far 
I have thought that SPARQL is the equivalent to the SQL language in the 
relational databases, that is to say, that with SPARQL it is only possible to 
consult the data that are explicitly in the ontology, without having access to 
the data that can be inferred , leaving the responsibility of the inference to 
the reasoners.
 
However, I have read documents from which I infer that SPARQL does have the 
capacity to infer implicit and non-explicit knowledge in the ontology. Is my 
inference true? That is, is it possible to infer knowledge through a SPARQL 
query without the need for a reasoner? If the answer is true, then what 
advantages does the use of a reasoner have over the use of SPARQL?

   

Greetings, Manuel Puebla. 

objects properties as inverse and at the same time disjoint

[Manuel Enrique Puebla Martinez]

Hello :

  Is it an error to define two properties of objects as inverse to each other 
and at the same time disjunct?

The reasoner HermiT 1.3.8.3 is generating the following error and I am 
suspecting that is why:

However, other reasoners and evaluative tools such as OOPS, Pellet and TrOWL do 
not report this error.

Best regards, MAnuel Puebla.
La @universidad_uci es Fidel: 15 años conectados al futuro... conectados a la 
Revolución
2002-2017

Fwd: OWL2 Support in Jena

[Manuel Enrique Puebla Martinez]

Hello: 

Excuse my insistence, but I have some scientific curiosity and you could help 
me with that. 

About 3 years ago I began to review the existing literature on the topic of 
ontologies and the possibility of managing the semantics of the data. I came to 
have exchanges via mail with the Protégé team, which uses OWLAPI and not JENA 
in its latest versions. 

I had the choice between JENA and OWLAPI for the development of my doctoral 
thesis. The results of my analysis were very clear, everything pointed out that 
I had to use OWLAPI, mainly for the support to OWL2 which was of paramount 
importance for me. 

However, I have noticed that the JENA community is a lot, but much more active 
than that of OWLAPI. Could you tell me a bit about those reasons that incline 
you to use JENA? 

I know that JENA supports the management of ontologies in external memory, 
OWLAPI does not have support for that. Anything else? 

Best Regards, Manuel Puebla. 

- Mensaje original -

De: "Abduladem Eljamel" <a_elja...@yahoo.co.uk> 
Para: "Manuel Enrique Puebla Martinez" <mpue...@uci.cu> 
Enviados: Viernes, 26 de Mayo 2017 5:48:12 
Asunto: Re: [MASSMAIL]Re: OWL2 Support in Jena 

Thanks Manuel for your email 
I know that OWLAPI has a complete support for OWL2; however, I have specific 
reasons to use Jena. 
Regards 
Abdul 





From: Manuel Enrique Puebla Martinez <mpue...@uci.cu> 
To: Abduladem Eljamel <a_elja...@yahoo.co.uk> 
Sent: Thursday, 25 May 2017, 14:52 
Subject: Re: [MASSMAIL]Re: OWL2 Support in Jena 


The OWLAPI framework provides support for OWL2. I have used it without any 
problem. 


Greetings. 

- Mensaje original - 
De: "Abduladem Eljamel" < a_elja...@yahoo.co.uk.INVALID > 
Para: users@jena.apache.org 
Enviados: Jueves, 25 de Mayo 2017 3:23:35 
Asunto: [MASSMAIL]Re: OWL2 Support in Jena 


Thanks Lorenz 


What does it mean that "OWL2 support in Jena will be added in due course"? 

The documentation of Jena mentioned that Jena has a limited support for OWL2's 
qualified cardinality restrictions as the example you have presented, but are 
the other restrictions, existential and universal, supported? For example, 

hasChild someValueFrom Person 
hasChild allValueFrom Person 
?? 
abdul 



From: Lorenz Buehmann < buehm...@informatik.uni-leipzig.de > 
To: users@jena.apache.org 
Sent: Wednesday, 24 May 2017, 14:03 
Subject: Re: OWL2 Support in Jena 

OWL 2 supports more features, e.g. qualified cardinality restrictions like 

hasChild min 1 Person 

in OWL 1 you could only say 

hasChild min 1 


On 24.05.2017 14:25, Abduladem Eljamel wrote: 
> Thank Lorenz for answering my email However, what do you mean by "OWL-2 class 
> expressions"?What is the difference from OWL-1 class expressions? I am sorry 
> it could be a basic question but could you pleasegive me an example? Thanks 
> Abdul 
> 
> From: Lorenz Buehmann < buehm...@informatik.uni-leipzig.de > 
> To: users@jena.apache.org 
> Sent: Thursday, 18 May 2017, 12:47 
> Subject: Re: OWL2 Support in Jena 
> 
> Jena support anything serialized in RDF and moreover, it supports OWL 1. 
> Indeed, you can load any OWL 2 ontology into Jena but there are no 
> convenience methods/objects to handle e.g. OWL 2 class expressions. 
> 
> 
> On 18.05.2017 13:28, Abduladem Eljamel wrote: 
>> Hello All ,, 
>> I have read in Jena website that "OWL2 support in Jena will be added in due 
>> course." Also, the wesite mentioned that Jena has a limited support for 
>> OWL2's qualified cardinality restrictions. 
>> 
>> Does Jena have a support for OWL2 Ontolgies which are created by other 
>> ontology editors such as Protege? specifically, existential and universal 
>> restrictions. 
>> ThanksAbdul 

> 
> 
> 




La @universidad_uci es Fidel. Los jóvenes no fallaremos. 
#HastaSiempreComandante 
#HastalaVictoriaSiempre 





La @universidad_uci es Fidel. Los jóvenes no fallaremos.
#HastaSiempreComandante
#HastalaVictoriaSiempre

Re: Re: "DisjointDataProperties" only for the data properties of a class. (Samson Tu)

[Manuel Enrique Puebla Martinez]

Dear Samson Tu:

Thanks for answering, however, do not you know a way to specify it in the 
ontology without using reasoners?

I ask because in my case, the size of my ontology does not allow me to make use 
of the reasoners. The reasoning skills I have to develop myself, adjusted to my 
particular needs. For this reason, I need a way to translate that knowledge 
into the ontology so that I can use it later.

Best regards. 



Message: 1
Date: Thu, 18 May 2017 15:46:03 -0700
From: Samson Tu <s...@stanford.edu>
To: User support for WebProtege and Protege Desktop
<protege-u...@lists.stanford.edu>
Subject: Re: [protege-user] "DisjointDataProperties" only for the data
properties of a class.
Message-ID: <36b01b11-05b2-476b-a339-bf5ca700d...@stanford.edu>
Content-Type: text/plain; charset="us-ascii"


> On May 17, 2017, at 7:27 PM, Manuel Enrique Puebla Martinez <mpue...@uci.cu> 
> wrote:
> 
> I have a modeling doubt.
> 
> I want to specify that a class in my ontology has a set of data properties 
> whose values are not repeated only for that class.
> 
> "DisjointDataProperties allows it to be asserted that several data properties 
> are pairwise incompatible (exclusive)." However, this will be true for all 
> classes of my ontology that use the data properties specified as disjoint. I 
> need the restriction to apply only to one class and not all. How can I model 
> this in OWL2?
> 

One possibility is to write a rule: ExampleClass(?i), p1(?i, ?v), p2(?i, ?v) -> 
owl:Nothing(?i), where p1 and p2 have been defined as data properties.

Interestingly, different reasoners behave differently when there is an instance 
that have a common value for the two properties. Pellet throws an inconsistent 
ontology error. Hermit displays a dialog box and offers to give explanation for 
the inconsistent ontology. FaCT++ shows nothing, but a DL query of ExampleClass 
shows that it is a subclass of owl:Nothing.

With best regards,
Samson

-- 
Samson Tu  email: 
s...@stanford.edu
Senior Research Engineer  web: 
www.stanford.edu/~swt/
Center for Biomedical Informatics Research  phone: 1-650-725-3391
Stanford University  fax: 1-650-725-7944

La @universidad_uci es Fidel. Los jóvenes no fallaremos.
#HastaSiempreComandante
#HastalaVictoriaSiempre

Re: [MASSMAIL]Re: about TDB JENA

[Manuel Enrique Puebla Martinez]

 
 I'm not sure I completely understood your answer. Please confirm my 
interpretation.

I think I have understood, that the solution is to write rule-based 
materialization that substitute the reasoners. Apparently since TDB it is 
possible to execute those rules of inferences on my big ontology, is it?

It seems that rule-based materialization is not applicable to OWL2 ontologies 
(which do not fit into any of the profiles), is it?

Greetings and thank you very much for your time.


- Mensaje original -
De: "Lorenz B." <buehm...@informatik.uni-leipzig.de>
Para: users@jena.apache.org
Enviados: Lunes, 20 de Marzo 2017 2:24:33
Asunto: Re: [MASSMAIL]Re: about TDB JENA


It totally depends on the reasoning that you want to apply. OWL 2 DL is
not possible via simple rules, but for instance RDFS/OLW Horst and OWL
RL can be doen via rule-based materialization.
>  I keep going into details, thank you for responding.
>
> Of the 13 million property assertions, almost 80% are assertions of object 
> properties, ie relationships between individuals. In the last ontology I 
> generated automatically, only for one of the municipalities in Cuba, I had 27 
> 763 887 of object properties assertions, 105 054 data property assertions and 
> 8 158 individuals.
>
> The inference I need is basically the following:
>
> 1) To know all the individuals that belong to a class directly and 
> indirectly, taking into consideration the equivalence between classes and 
> between individuals.
Depends on the reasoning profile and the ontology schema, but might be
covered by SPARQL 1.1 as long as you need only RDFS/OWL RL reasoning.
>
> 2) Given an individual (Ind) and an object property (OP), know all 
> individuals related to "Ind", through OP. Considering the following 
> characteristics of OP: symmetry, functional, transitivity, inverse, 
> equivalence.
>
> 3) Search the direct and indirect subclasses of a class.
SPARQL 1.1 property paths as long as the classes are atomic classes and
not complex class expressions.
>
> 4) Identify all classes equivalent to a class, considering that the 
> equivalence relation is transitive.
>
> 5) Identify the set of superclasses of a class.
SPARQL 1.1 property paths as long as the classes are atomic classes and
not complex class expressions.
>
> Could JENA and TDB afford that kind of inference on my big ontologies?
>
> Excuse me, but I'm not a deep connoisseur of the SPARQL language. I have only 
> used it to access data that is explicit on the ontology, similar to SQL in 
> relational databases, I have never used it (nor do I know if it is possible 
> to do so) to infer implicit knowledge.
The approach that people do is either query rewriting w.r.t. the schema
or forward-chaining, i.e. materialization based on a set of inference
rules. For RDFS, OWL Horst and OWL RL this is possible. Materialization
has to be done only once (given that the dataset does not change).
>
> I put copy to Ignazio Palmisano, an excellent researcher and connoisseur of 
> the framework OWLAPI. With which I have been exchanging on this subject.
>
> Best regards.
>
>
> - Mensaje original -
> De: "Dave Reynolds" <dave.e.reyno...@gmail.com>
> Para: users@jena.apache.org
> Enviados: Domingo, 19 de Marzo 2017 13:45:48
> Asunto: Re: [MASSMAIL]Re: about TDB JENA
>
> On 19/03/17 15:52, Manuel Enrique Puebla Martinez wrote:
>> I consider that I did not know how to explain correctly in my previous 
>> email, I repeat the two questions:
>>
>>
>> 1) I read the page https://jena.apache.org/documentation/tdb/assembler.html, 
>> I do not think it is what I need.
>>
>>I work with large OWL2 ontologies from the OWLAPI framework, generated 
>> automatically. With thousands of individuals and more than 13 million 
>> property assertions (data and objects). As one may assume, one of the 
>> limitations I have is that OWLAPI itself can not manage these large 
>> ontologies, that is, because OWLAPI loads the whole owl file into RAM. Not 
>> to dream that some classical reasoner (Pellet, Hermit, etc.) can infer new 
>> knowledge about these great ontologies.
>>
>> Once explained the problem I have, comes the question: Does JENA solve this 
>> test ?, ie with JENA and TDB I can generate my great ontologies in OWL2 ?, 
>> With JENA and TDB I can use a reasoner to infer new implicit knowledge 
>> (unstated) on my big ontologies?
>>
>> I do not think JENA will be able to solve this problem, it would be a 
>> pleasant surprise for me. Unfortunately so far I had not read about TDB and 
>> the potentialities of JENA in external memory.
> Indeed Jena does not offer fully scalable reasoning, all inference is 
> done

Re: [MASSMAIL]Re: about TDB JENA

[Manuel Enrique Puebla Martinez]

I consider that I did not know how to explain correctly in my previous email, I 
repeat the two questions:


1) I read the page https://jena.apache.org/documentation/tdb/assembler.html, I 
do not think it is what I need.

   I work with large OWL2 ontologies from the OWLAPI framework, generated 
automatically. With thousands of individuals and more than 13 million property 
assertions (data and objects). As one may assume, one of the limitations I have 
is that OWLAPI itself can not manage these large ontologies, that is, because 
OWLAPI loads the whole owl file into RAM. Not to dream that some classical 
reasoner (Pellet, Hermit, etc.) can infer new knowledge about these great 
ontologies.

Once explained the problem I have, comes the question: Does JENA solve this 
test ?, ie with JENA and TDB I can generate my great ontologies in OWL2 ?, With 
JENA and TDB I can use a reasoner to infer new implicit knowledge (unstated) on 
my big ontologies?

I do not think JENA will be able to solve this problem, it would be a pleasant 
surprise for me. Unfortunately so far I had not read about TDB and the 
potentialities of JENA in external memory.

Best Regards, Manuel Puebla.


- Mensaje original -
De: "Lorenz B." 
Para: users@jena.apache.org
Enviados: Domingo, 19 de Marzo 2017 3:52:30
Asunto: [MASSMAIL]Re: about TDB JENA


> Is it possible to use some reasoner with RDF data, managed from TDB? 
Yes, see [1]
>
> Is it possible to manage an ontology in OWL2 from TDB? 
What means "manage"? In general you can load and query any RDF data into
TDB. The serialization of an OWL ontology can be any RDF format.
Obviously, querying OWL constructs via SPARQL can become weird because
an OWL axiom/class expression can consists of more than one RDF triple.

[1] https://jena.apache.org/documentation/tdb/assembler.html

-- 
Lorenz Bühmann
AKSW group, University of Leipzig
Group: http://aksw.org - semantic web research center

La @universidad_uci es Fidel. Los jóvenes no fallaremos.
#HastaSiempreComandante
#HastalaVictoriaSiempre