Stack Overflow
Stack Overflow

Questions tagged [description-logic]

Description logics (DL) is a family of formal knowledge representation languages. It is more expressive than propositional logic. Additionally, it has more efficient decision problems than first-order predicate logic.

Resources

121 questions
1
vote
1 answer

ALC: define an ALC Knowledge Base

Hello I am new to description logics and ALC and I find it confusing defining a KB. More specifically I am trying to create an ALC KB for the first 3 sentences below and an ALC formula φ that formalizes the last one. Sentences: • Anna is a person. •…
C96
  • 477
  • 8
  • 33
1
vote
0 answers

OWL 2 QL axioms in simple language

I am new to ontology axioms and DL Syntax and trying to understand what exactly the axioms in the image mean. I have also given the reference from where I took the image paper. Kindly help me to understand these axioms.
fairyjee
  • 75
  • 1
  • 5
1
vote
2 answers

Description Logic representation that requires the modelling of sameness or distiction of two individuals

I am trying to model the following statement in Description Logic. A co-teaching faculty member is any person who is an academic staff and teaches at least one course that is taught by others The representation that I have thought of…
Plaban Kumar Bhowmik
  • 13
  • 2
1
vote
1 answer

Understanding universal restriction of a concept in Description Logic (DL)

I am trying to understand the following Passage from a DL tutorial in terms of First Order Logic (FOL). Passage To represent the set of individuals all of whose children are female, we use the universal restriction ∀parentOf.Female (16) It…
Patrick Browne
  • 243
  • 1
  • 8
1
vote
1 answer

Usage of Existential Quantifiers in Description Logic

I have difficulty understanding this statement in DL: ∃R.∃S.C(a) What does this proposition exactly mean? Thanks in advance!
Sara
  • 97
  • 6
1
vote
0 answers

Regularity of Rboxes in Description Logic

Based on the definition taken from Foundations of Semantic Web Technologies by Hitzler et al, a role hierarchy is called regular if there exists a strict partial order ≺ on R, such that the following hold: a) ○ S ≺ R if and only if S− ≺ R b) ○ every…
Sara
  • 97
  • 6
1
vote
0 answers

Under what conditions can query answering in OWL EL be done in PTIME?

Under what conditions can query answering in OWL EL be done in PTIME? Conjunctive query answering in OWL EL can be done in EXPTIME, and is PTIME-complete if the property hierarchy can be translated into a polynomially-sized nondeterministic finite…
user10264746
  • 59
  • 8
1
vote
0 answers

How to extract/build a Domain Model from Description Logic Knowledge Base(s)

hopefully my question is not trivial or already answered elsewhere. Problem Description Let's assume we have a DL Knowledge Base KmySys = (Tsys, AmySys) representing a software architecture. The knowledge KmySys models software components (e.g.,…
aky
  • 75
  • 4
1
vote
0 answers

Protégé reasoner does not infer subclass

I have a small ontology defined as shown in the following picture: I created an individual for Dataset and one for Algorithm. I expected that the reasoner would infer the Algorithm individual as Linear_Least_Regression, but this didn't…
Paul
  • 1,325
  • 2
  • 19
  • 41
1
vote
1 answer

Why can't I directly use merger in owlapi to merge ABox and TBox?

owlapi provides us a class merger, which allow us to load ontology from multiple files/sources and then merge them together. Now I have my ontology split into two disjoint parts, i.e., a part for TBox axioms and the other for ABox assertions. So I…
Yu Gu
  • 2,382
  • 5
  • 18
  • 33
1
vote
0 answers

Datalog Coloring Objects

Sorry for the maybe stupid question, but I'm struggling with a problem concerning constraints in datalog. I basically have to color 2 objects with 2 different colors. The problem is that the constraint that I have to define for "2 objects can't have…
Nooneye
  • 13
  • 3
1
vote
1 answer

Can this be expressed using ALCQ syntax?

Is it valid, using ALCQ, to write: likes ≡ ¬dislikes ¬∃(Dog ⊓ dislikes.(Colourful ⊓ Toy)) in order to express that every dog likes the colourful toys? Also, is it valid to write: Cute(∀Pomeranian) in order to express that every pomeranian is…
LostIT
  • 247
  • 2
  • 10
1
vote
2 answers

In OWL 2, why is the semantics of key axioms specific to named individuals?

In the specification for OWL 2, the section on key axioms states: The semantics of key axioms is specific in that these axioms apply only to individuals explicitly introduced in the ontology by name, and not to unnamed individuals (i.e., the…
jdferreira
  • 651
  • 1
  • 6
  • 16
1
vote
1 answer

(Un)Inferred Subclass Rules Protégé vs OWL API

I am a bit confused about the subclass handling in Protégé as compared to when using the OWL API directly. I have built a simple ontology where I logically define what a "Man" or a "Woman" is, namely male or female humans. The classes…
khituras
  • 1,081
  • 10
  • 25
1
vote
1 answer

How to prove that something can *not* be translated into description logic?

My intuition says that it is not possible to translate the sentence all red cars are better than all blue cars into description logics (in FOL this would be ∀x∀y (red(x) ∧ blue(y) → better(x,y)) interpreted in the domain of cars). Indeed, the…
yannis
  • 819
  • 1
  • 9
  • 26
1 2 3
…
8 9