org.dllearner.utilities.owl

Class ConceptTransformation

java.lang.Object

org.dllearner.utilities.owl.ConceptTransformation

public class ConceptTransformation
extends Object

Concept transformation and concept checking methods.

Author:

Jens Lehmann

Field Summary

Fields

Modifier and Type	Field and Description
static long	cleaningTimeNs
static long	onnfTimeNs
static long	shorteningTimeNs

Constructor Summary

Constructors

Constructor and Description
ConceptTransformation()

Method Summary

Modifier and Type	Method and Description
static org.semanticweb.owlapi.model.OWLClassExpression	appendSomeValuesFrom(org.semanticweb.owlapi.model.OWLClassExpression ce) Expand the class expression by adding \exists r.\top for all properties r that are involved in some \forall r.C on the same modal depth.
static org.semanticweb.owlapi.model.OWLClassExpression	applyEquivalenceRules(org.semanticweb.owlapi.model.OWLClassExpression concept)
static org.semanticweb.owlapi.model.OWLClassExpression	cleanConcept(org.semanticweb.owlapi.model.OWLClassExpression concept)
static org.semanticweb.owlapi.model.OWLClassExpression	cleanConceptNonRecursive(org.semanticweb.owlapi.model.OWLClassExpression concept)
static SortedSet<PropertyContext>	getForallContexts(org.semanticweb.owlapi.model.OWLClassExpression description) Gets the "contexts" of all \forall occurrences in a description.
static int	getForallOccurences(org.semanticweb.owlapi.model.OWLClassExpression description) Counts occurrences of \forall in description.
static org.semanticweb.owlapi.model.OWLClassExpression	getShortConcept(org.semanticweb.owlapi.model.OWLClassExpression concept) Tries to shorten a concept, e.g.
static boolean	isDescriptionMinimal(org.semanticweb.owlapi.model.OWLClassExpression description) Method to determine, whether a class expression is minimal, e.g.
static boolean	isSubdescription(org.semanticweb.owlapi.model.OWLClassExpression description, org.semanticweb.owlapi.model.OWLClassExpression subDescription) Tests whether a description is a subdescription in the sense that when parts of description can be removed to yield subdescription.
static org.semanticweb.owlapi.model.OWLClassExpression	nnf(org.semanticweb.owlapi.model.OWLClassExpression ce) Returns the class expression in negation normal form.
static org.semanticweb.owlapi.model.OWLClassExpression	replaceRange(org.semanticweb.owlapi.model.OWLClassExpression description, AbstractReasonerComponent rs)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

cleaningTimeNs

public static long cleaningTimeNs

onnfTimeNs

public static long onnfTimeNs

shorteningTimeNs

public static long shorteningTimeNs

Constructor Detail

ConceptTransformation

public ConceptTransformation()

Method Detail

cleanConceptNonRecursive

public static org.semanticweb.owlapi.model.OWLClassExpression cleanConceptNonRecursive(org.semanticweb.owlapi.model.OWLClassExpression concept)

cleanConcept

public static org.semanticweb.owlapi.model.OWLClassExpression cleanConcept(org.semanticweb.owlapi.model.OWLClassExpression concept)

nnf

public static org.semanticweb.owlapi.model.OWLClassExpression nnf(org.semanticweb.owlapi.model.OWLClassExpression ce)

Returns the class expression in negation normal form.

Parameters:

ce - the class expression

Returns:

the class expression in negation normal form

appendSomeValuesFrom

public static org.semanticweb.owlapi.model.OWLClassExpression appendSomeValuesFrom(org.semanticweb.owlapi.model.OWLClassExpression ce)

Expand the class expression by adding \exists r.\top for all properties r that are involved in some \forall r.C on the same modal depth.

Parameters:

ce - the class expression to expand

Returns:

applyEquivalenceRules

public static org.semanticweb.owlapi.model.OWLClassExpression applyEquivalenceRules(org.semanticweb.owlapi.model.OWLClassExpression concept)

getShortConcept

public static org.semanticweb.owlapi.model.OWLClassExpression getShortConcept(org.semanticweb.owlapi.model.OWLClassExpression concept)

Tries to shorten a concept, e.g. male AND male is shortened to male.

Parameters:

concept - The input concepts.

Returns:

A shortened version of the concept (equal to the input concept if it cannot be shortened).

isDescriptionMinimal

public static boolean isDescriptionMinimal(org.semanticweb.owlapi.model.OWLClassExpression description)

Method to determine, whether a class expression is minimal, e.g. \forall r.\top (\equiv \top) or male \sqcup male are not minimal. This method performs heuristic sanity checks (it will not try to find semantically equivalent shorter descriptions).

Parameters:

description - Input description.

Returns:

True if a superfluous construct has been found.

replaceRange

public static org.semanticweb.owlapi.model.OWLClassExpression replaceRange(org.semanticweb.owlapi.model.OWLClassExpression description,
                                                                           AbstractReasonerComponent rs)

isSubdescription

public static boolean isSubdescription(org.semanticweb.owlapi.model.OWLClassExpression description,
                                       org.semanticweb.owlapi.model.OWLClassExpression subDescription)

Tests whether a description is a subdescription in the sense that when parts of description can be removed to yield subdescription.

Parameters:

description - A description.

subDescription - A potential subdescription.

Returns:

True if subdescription is indeed a sub description and false otherwise.

getForallOccurences

public static int getForallOccurences(org.semanticweb.owlapi.model.OWLClassExpression description)

Counts occurrences of \forall in description.

Parameters:

description - A description.

Returns:

Number of \forall occurrences.

getForallContexts

public static SortedSet<PropertyContext> getForallContexts(org.semanticweb.owlapi.model.OWLClassExpression description)

Gets the "contexts" of all \forall occurrences in a description. A context is a set of properties, i.e. in \exists hasChild.\exists hasBrother.\forall hasChild.male, the context of the only \forall occurrence is [hasChild, hasBrother, hasChild].

Parameters:

description - A description.

Returns:

Set of property contexts.