Package net.sf.tweety.logics.dl.syntax

Class EquivalenceAxiom

java.lang.Object

net.sf.tweety.logics.dl.syntax.DlAxiom

net.sf.tweety.logics.dl.syntax.EquivalenceAxiom

All Implemented Interfaces:

Formula, SimpleLogicalFormula

public class EquivalenceAxiom
extends DlAxiom

This class models an equivalence axiom, also known as general concept inclusion (GCU), meaning an expression of the form "C is a subset of or equal to D" with C and D as Concepts. This can also be read as "C implies D". If C implies D and C implies C, the two concepts are equivalent.
Equivalence axioms are used in the TBox of a DL knowledge base to model relationships between concepts, e.g. "MaleHuman is a subset or equal to Human".

Author:

Anna Gessler

Field Summary

Fields

Modifier and Type	Field	Description
private Pair<ComplexConcept,ComplexConcept>	axiom

Constructor Summary

Constructors

Constructor	Description
EquivalenceAxiom(ComplexConcept c, ComplexConcept d)	Creates a new equivalence axiom with the given formulas (atomic or complex concepts).

Method Summary

Modifier and Type	Method	Description
EquivalenceAxiom	clone()	Creates a deep copy of this formula
boolean	equals(java.lang.Object obj)
Pair<ComplexConcept,ComplexConcept>	getFormulas()
java.util.Set<Predicate>	getPredicates()	Processes the set of all predicates which appear in this formula
DlSignature	getSignature()	Returns the signature of the language of this formula.
int	hashCode()
boolean	isLiteral()
java.lang.String	toString()

Methods inherited from class net.sf.tweety.logics.dl.syntax.DlAxiom

getAtoms, getPredicateCls

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

axiom

private Pair<ComplexConcept,ComplexConcept> axiom

Constructor Detail

EquivalenceAxiom

public EquivalenceAxiom(ComplexConcept c,
                        ComplexConcept d)

Creates a new equivalence axiom with the given formulas (atomic or complex concepts).

Parameters:

c - some concept

d - some concept

Method Detail

getSignature

public DlSignature getSignature()

Description copied from interface: Formula

Returns the signature of the language of this formula.

Specified by:

getSignature in interface Formula

Specified by:

getSignature in class DlAxiom

Returns:

the signature of the language of this formula.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getFormulas

public Pair<ComplexConcept,ComplexConcept> getFormulas()

getPredicates

public java.util.Set<Predicate> getPredicates()

Description copied from interface: SimpleLogicalFormula

Processes the set of all predicates which appear in this formula

Specified by:

getPredicates in interface SimpleLogicalFormula

Specified by:

getPredicates in class DlAxiom

Returns:

all predicates that appear in this formula

isLiteral

public boolean isLiteral()

Specified by:

isLiteral in interface SimpleLogicalFormula

Overrides:

isLiteral in class DlAxiom

Returns:

true if the formula represents a literal in the language or false otherwise

clone

public EquivalenceAxiom clone()

Description copied from interface: SimpleLogicalFormula

Creates a deep copy of this formula

Specified by:

clone in interface SimpleLogicalFormula

Specified by:

clone in class DlAxiom

Returns:

the cloned formula

hashCode

public int hashCode()

Specified by:

hashCode in interface SimpleLogicalFormula

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Specified by:

equals in interface SimpleLogicalFormula

Overrides:

equals in class java.lang.Object