net.sf.tweety.lp.asp.syntax

Class AggregateAtom

java.lang.Object

net.sf.tweety.lp.asp.syntax.ASPElement

net.sf.tweety.lp.asp.syntax.ASPBodyElement

net.sf.tweety.lp.asp.syntax.AggregateAtom

All Implemented Interfaces:

net.sf.tweety.commons.Formula, net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula, net.sf.tweety.logics.commons.syntax.interfaces.LogicStructure, net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

public class AggregateAtom
extends ASPBodyElement

This class represents an aggregate. Aggregates are functions that range over sets of terms and literals and evaluate to some value. For example, using the aggregate function #count one could obtain the number of employees of one department. Normally, this value is then compared to another value with a comparative operator like "=" to produce a truth value (also known as 'aggregate relation'). For example, this could be used to express the condition that the number of employees in one department has to be greater than 0.
An aggregate that contains such a comparison is also referred to as an aggregate atom and can appear in the body of a rule.

Author:

Tim Janus, Thomas Vengels, Anna Gessler

Constructor Summary

Constructors

Constructor and Description
AggregateAtom() Empty default constructor.
AggregateAtom(AggregateAtom other) Copy-Constructor
AggregateAtom(ASPOperator.AggregateFunction func, List<AggregateElement> elements) Creates a new Aggregate with the given aggregate function and the given aggregate elements.
AggregateAtom(ASPOperator.AggregateFunction func, List<AggregateElement> elements, ASPOperator.BinaryOperator relation, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t) Creates a new Aggregate with the given aggregate function, the given aggregate elements, and the given aggregate relation.
AggregateAtom(ASPOperator.AggregateFunction func, List<AggregateElement> elements, ASPOperator.BinaryOperator relation, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t, ASPOperator.BinaryOperator relation2, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t2) Creates a new Aggregate with the given aggregate function, the given aggregate elements, and the given left and right aggregate relations.

Method Summary

Modifier and Type	Method and Description
AggregateAtom	clone()
List<AggregateElement>	getAggregateElements()
Set<ASPAtom>	getAtoms()
ASPOperator.AggregateFunction	getFunction() Returns the aggregate function.
net.sf.tweety.logics.commons.syntax.interfaces.Term<?>	getLeftGuard() Get the left relation term (right guard).
ASPOperator.BinaryOperator	getLeftOperator() Returns the operator of the left aggregate relation.
SortedSet<ASPLiteral>	getLiterals() Returns all literals in this element in form of a SortedSet.
Set<net.sf.tweety.logics.commons.syntax.Predicate>	getPredicates()
net.sf.tweety.logics.commons.syntax.interfaces.Term<?>	getRightGuard() Returns the right relation term (right guard).
ASPOperator.BinaryOperator	getRightOperator() Returns the operator of the right aggregate relation.
net.sf.tweety.logics.fol.syntax.FolSignature	getSignature()
Set<net.sf.tweety.logics.commons.syntax.interfaces.Term<?>>	getTerms()
<C extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> Set<C>	getTerms(Class<C> cls)
boolean	hasLeftRelation() Returns true if the aggregate has a left aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).
boolean	hasRightRelation() Returns true if the aggregate has a right aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).
boolean	isLiteral()
void	setFunction(ASPOperator.AggregateFunction function) Sets the aggregate function.
void	setLeftGuard(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> relationTerm) Set the left relation term (right guard).
void	setLeftOperator(ASPOperator.BinaryOperator op) Sets the operator of the left aggregate relation.
void	setRightGuard(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> relationTerm) Set the right relation term (right guard).
void	setRightOperator(ASPOperator.BinaryOperator op) Sets the operator of the right aggregate relation.
AggregateAtom	substitute(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v)
String	toString()

Methods inherited from class net.sf.tweety.lp.asp.syntax.ASPElement

containsTermsOfType, exchange, getPredicateCls, isGround, isWellFormed, substitute

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

equals, hashCode

Constructor Detail

AggregateAtom

public AggregateAtom()

Empty default constructor.

AggregateAtom

public AggregateAtom(ASPOperator.AggregateFunction func,
                     List<AggregateElement> elements)

Creates a new Aggregate with the given aggregate function and the given aggregate elements.

Parameters:

func - an aggregate function

elements - list of aggregate elements

AggregateAtom

public AggregateAtom(ASPOperator.AggregateFunction func,
                     List<AggregateElement> elements,
                     ASPOperator.BinaryOperator relation,
                     net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t)

Creates a new Aggregate with the given aggregate function, the given aggregate elements, and the given aggregate relation.

Parameters:

func - an aggregate function

elements - list of aggregate elements

AggregateAtom

public AggregateAtom(ASPOperator.AggregateFunction func,
                     List<AggregateElement> elements,
                     ASPOperator.BinaryOperator relation,
                     net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t,
                     ASPOperator.BinaryOperator relation2,
                     net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t2)

Creates a new Aggregate with the given aggregate function, the given aggregate elements, and the given left and right aggregate relations.

Parameters:

func - an aggregate function

elements - list of aggregate elements

AggregateAtom

public AggregateAtom(AggregateAtom other)

Copy-Constructor

Parameters:

other -

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getLiterals

public SortedSet<ASPLiteral> getLiterals()

Description copied from class: ASPBodyElement

Returns all literals in this element in form of a SortedSet. Literals are atoms or strict negations of atoms.

Specified by:

getLiterals in class ASPBodyElement

Returns:

all the literals used in the rule element

getPredicates

public Set<net.sf.tweety.logics.commons.syntax.Predicate> getPredicates()

Specified by:

getPredicates in interface net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

Specified by:

getPredicates in class ASPElement

getAtoms

public Set<ASPAtom> getAtoms()

Specified by:

getAtoms in interface net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

Specified by:

getAtoms in class ASPElement

substitute

public AggregateAtom substitute(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t,
                                net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v)

Specified by:

substitute in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Specified by:

substitute in class ASPBodyElement

getSignature

public net.sf.tweety.logics.fol.syntax.FolSignature getSignature()

Specified by:

getSignature in interface net.sf.tweety.commons.Formula

Specified by:

getSignature in class ASPElement

clone

public AggregateAtom clone()

Specified by:

clone in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Specified by:

clone in interface net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

Specified by:

clone in class ASPElement

isLiteral

public boolean isLiteral()

getTerms

public Set<net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> getTerms()

getTerms

public <C extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> Set<C> getTerms(Class<C> cls)

getAggregateElements

public List<AggregateElement> getAggregateElements()

hasLeftRelation

public boolean hasLeftRelation()

Returns true if the aggregate has a left aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).

Returns:

true if aggregate has left aggregate relation

hasRightRelation

public boolean hasRightRelation()

Returns true if the aggregate has a right aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).

Returns:

true if aggregate has right aggregate relation

getFunction

public ASPOperator.AggregateFunction getFunction()

Returns the aggregate function.

Returns:

an aggregate function

setFunction

public void setFunction(ASPOperator.AggregateFunction function)

Sets the aggregate function.

Parameters:

an - aggregate function

getRightOperator

public ASPOperator.BinaryOperator getRightOperator()

Returns the operator of the right aggregate relation.

Returns:

comparative operator

setRightOperator

public void setRightOperator(ASPOperator.BinaryOperator op)

Sets the operator of the right aggregate relation.

Parameters:

comparative - operator

getRightGuard

public net.sf.tweety.logics.commons.syntax.interfaces.Term<?> getRightGuard()

Returns the right relation term (right guard).

Returns:

Term

setRightGuard

public void setRightGuard(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> relationTerm)

Set the right relation term (right guard).

Parameters:

Term -

getLeftOperator

public ASPOperator.BinaryOperator getLeftOperator()

Returns the operator of the left aggregate relation.

Returns:

comparative operator

setLeftOperator

public void setLeftOperator(ASPOperator.BinaryOperator op)

Sets the operator of the left aggregate relation.

Parameters:

comparative - operator

getLeftGuard

public net.sf.tweety.logics.commons.syntax.interfaces.Term<?> getLeftGuard()

Get the left relation term (right guard).

Returns:

Term

setLeftGuard

public void setLeftGuard(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> relationTerm)

Set the left relation term (right guard).

Parameters:

Term -