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

static long	cleaningTimeNs
static long	onnfTimeNs
static long	shorteningTimeNs

Constructor Summary

ConceptTransformation()

Method Summary

static Description	applyEquivalenceRules(Description concept)
static void	cleanConcept(Description concept)
static void	cleanConceptNonRecursive(Description concept)
static SortedSet<PropertyContext>	getForallContexts(Description description) Gets the "contexts" of all \forall occurrences in a description.
static int	getForallOccurences(Description description) Counts occurrences of \forall in description.
static Description	getShortConcept(Description concept, ConceptComparator conceptComparator) Tries to shorten a concept, e.g. male AND male is shortened to male.
static Description	getShortConceptNonRecursive(Description concept, ConceptComparator conceptComparator)
static boolean	isDescriptionMinimal(Description description) Method to determine, whether a class description is minimal, e.g.
static boolean	isSubdescription(Description description, Description subDescription) Tests whether a description is a subdescription in the sense that when parts of description can be removed to yield subdescription.
static void	replaceRange(Description description, AbstractReasonerComponent rs)
static Description	transformToNegationNormalForm(Description concept)
static void	transformToOrderedForm(Description concept, Comparator<Description> conceptComparator)
static void	transformToOrderedNegationNormalFormNonRecursive(Description concept, Comparator<Description> conceptComparator)

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 void cleanConceptNonRecursive(Description concept)

cleanConcept

public static void cleanConcept(Description concept)

transformToNegationNormalForm

public static Description transformToNegationNormalForm(Description concept)

applyEquivalenceRules

public static Description applyEquivalenceRules(Description concept)

transformToOrderedNegationNormalFormNonRecursive

public static void transformToOrderedNegationNormalFormNonRecursive(Description concept,
                                                                    Comparator<Description> conceptComparator)

transformToOrderedForm

public static void transformToOrderedForm(Description concept,
                                          Comparator<Description> conceptComparator)

getShortConceptNonRecursive

public static Description getShortConceptNonRecursive(Description concept,
                                                      ConceptComparator conceptComparator)

getShortConcept

public static Description getShortConcept(Description concept,
                                          ConceptComparator conceptComparator)

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

Parameters:

concept - The input concepts.

conceptComparator - A comparator for concepts.

Returns:

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

isDescriptionMinimal

public static boolean isDescriptionMinimal(Description description)

Method to determine, whether a class description 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 void replaceRange(Description description,
                                AbstractReasonerComponent rs)

isSubdescription

public static boolean isSubdescription(Description description,
                                       Description 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(Description description)

Counts occurrences of \forall in description.

Parameters:

description - A description.

Returns:

Number of \forall occurrences.

getForallContexts

public static SortedSet<PropertyContext> getForallContexts(Description 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.