net.sf.tweety.arg.aba

Class ABATheory<T extends Formula>

java.lang.Object

net.sf.tweety.arg.aba.ABATheory<T>

Type Parameters:

T - is the type of the language that the ABA theory's rules range over

All Implemented Interfaces:

BeliefBase

public class ABATheory<T extends Formula>
extends java.lang.Object
implements BeliefBase

Author:

Nils Geilen An implementation of Assumption Based Argumentation

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Collection<Assumption<T>>	assumptions The assumptions used in this theory wehen no explicit set of assumptions is given
private java.util.Collection<Negation<T>>	negations The negation relation
private java.util.Collection<InferenceRule<T>>	rules The inference rules

Constructor Summary

Constructors

Constructor and Description
ABATheory()

Method Summary

Modifier and Type	Method and Description
void	add(Formula rule)
void	addAssumption(T assumption)
void	addNegation(T formula, T negation) Adds a negation of form not formula = negation
DungTheory	asDungTheory()
(package private) boolean	attacks(java.util.Collection<Assumption<T>> atters, java.util.Collection<Assumption<T>> atteds)
boolean	attacks(Deduction<T> atter, T atted)
private Deduction<T>	createDeduction(DigraphNode<ABARule<T>> node, java.util.Set<Deduction<T>> set) Recursively creates a deduction and all of its subdeductions
(package private) boolean	defends(java.util.Collection<Assumption<T>> defor, Assumption<T> defed) Checks whether a set of arguments defends an argument
(package private) java.util.Collection<java.util.Collection<Assumption<T>>>	getAllAdmissbleExtensions() Computes all admissible extensions
(package private) java.util.Collection<java.util.Collection<Assumption<T>>>	getAllConflictFreeExtensions() Computes all context-free extensions
java.util.Collection<Deduction<T>>	getAllDeductions()
java.util.Collection<Deduction<T>>	getAllDeductions(java.util.Collection<Assumption<T>> assumptions)
(package private) java.util.Collection<java.util.Collection<Assumption<T>>>	getAllExtensions() Computes all possible extensions
java.util.Collection<Assumption<T>>	getAssumptions()
java.util.Collection<Assumption<T>>	getClosure(java.util.Collection<Assumption<T>> assumptions) A closure is the set of assumptions that can be derived from a set of assumptions via inference rules
java.util.Collection<Negation<T>>	getNegations()
java.util.Collection<InferenceRule<T>>	getRules()
Signature	getSignature() Returns the signature of the language of this knowledge base.
(package private) boolean	isAdmissible(java.util.Collection<Assumption<T>> ext) Checks whether a set of arguments is admissible
boolean	isClosed(java.util.Collection<Assumption<T>> assumptions) A set of assumptions is closed iff it equals its closure
(package private) boolean	isConflictFree(java.util.Collection<Assumption<T>> ext) Checks whether a set of arguments is conflict-free
boolean	isFlat() An ABA theory is flat iff all subsets of its argumentation set are closed
boolean	negates(T negation, T formula)
void	setAssumptions(java.util.Collection<Assumption<T>> assumptions)
private static <S> java.util.Collection<java.util.Collection<S>>	toPowerSet(java.util.Collection<S> set) Computes the power set of a collection
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

rules

private java.util.Collection<InferenceRule<T extends Formula>> rules

The inference rules

assumptions

private java.util.Collection<Assumption<T extends Formula>> assumptions

The assumptions used in this theory wehen no explicit set of assumptions is given

negations

private java.util.Collection<Negation<T extends Formula>> negations

The negation relation

Constructor Detail

ABATheory

public ABATheory()

Method Detail

getAllDeductions

public java.util.Collection<Deduction<T>> getAllDeductions()

Returns:

all deductions that can be derived from this theory

getAllDeductions

public java.util.Collection<Deduction<T>> getAllDeductions(java.util.Collection<Assumption<T>> assumptions)

Parameters:

assumptions - the set of assumptions used for the derivation

Returns:

all deductions that can be derived from this theory

createDeduction

private Deduction<T> createDeduction(DigraphNode<ABARule<T>> node,
                                     java.util.Set<Deduction<T>> set)

Recursively creates a deduction and all of its subdeductions

Parameters:

node -

set -

Returns:

the created deduction

getClosure

public java.util.Collection<Assumption<T>> getClosure(java.util.Collection<Assumption<T>> assumptions)

A closure is the set of assumptions that can be derived from a set of assumptions via inference rules

Parameters:

assumptions - a set of assumptions

Returns:

the closure of assumptions

isClosed

public boolean isClosed(java.util.Collection<Assumption<T>> assumptions)

A set of assumptions is closed iff it equals its closure

Parameters:

assumptions - a set of assumptions

Returns:

true iff the set of assumptions is closed under this argumentation theory

isFlat

public boolean isFlat()

An ABA theory is flat iff all subsets of its argumentation set are closed

Returns:

true iff the theory is flat

toPowerSet

private static <S> java.util.Collection<java.util.Collection<S>> toPowerSet(java.util.Collection<S> set)

Computes the power set of a collection

Parameters:

set - a collection

Returns:

a power set

add

public void add(Formula rule)

Parameters:

rule - an assumption or an inference rule or a negation that is added to the theory

addAssumption

public void addAssumption(T assumption)

Parameters:

assumption - a formula that is used as an assumption in the theory

addNegation

public void addNegation(T formula,
                        T negation)

Adds a negation of form not formula = negation

Parameters:

formula - a formula

negation - it's complement

negates

public boolean negates(T negation,
                       T formula)

Parameters:

formula -

negation -

Returns:

attacks

public boolean attacks(Deduction<T> atter,
                       T atted)

Parameters:

atter - the attacking deduction

atted - the attacked assumption

Returns:

true iff atter attacks atted

getRules

public java.util.Collection<InferenceRule<T>> getRules()

Returns:

the rules

getAssumptions

public java.util.Collection<Assumption<T>> getAssumptions()

Returns:

the assumptions

getNegations

public java.util.Collection<Negation<T>> getNegations()

Returns:

the negations

setAssumptions

public void setAssumptions(java.util.Collection<Assumption<T>> assumptions)

Parameters:

assumptions - the assumptions to set

attacks

boolean attacks(java.util.Collection<Assumption<T>> atters,
                java.util.Collection<Assumption<T>> atteds)

defends

boolean defends(java.util.Collection<Assumption<T>> defor,
                Assumption<T> defed)

Checks whether a set of arguments defends an argument

Parameters:

defor - the defending set

defed - the assumption which shall be defended

Returns:

true iff defor defends defed

isConflictFree

boolean isConflictFree(java.util.Collection<Assumption<T>> ext)

Checks whether a set of arguments is conflict-free

Parameters:

ext - a set of arguments

Returns:

true iff ext is conflict-free

getAllExtensions

java.util.Collection<java.util.Collection<Assumption<T>>> getAllExtensions()

Computes all possible extensions

Returns:

the powerset of the assumptions

getAllConflictFreeExtensions

java.util.Collection<java.util.Collection<Assumption<T>>> getAllConflictFreeExtensions()

Computes all context-free extensions

Returns:

all context-free extensions

isAdmissible

boolean isAdmissible(java.util.Collection<Assumption<T>> ext)

Checks whether a set of arguments is admissible

Parameters:

ext - the set

Returns:

true iff ext is admissible

getAllAdmissbleExtensions

java.util.Collection<java.util.Collection<Assumption<T>>> getAllAdmissbleExtensions()

Computes all admissible extensions

Returns:

all admissible extensions

getSignature

public Signature getSignature()

Description copied from interface: BeliefBase

Returns the signature of the language of this knowledge base.

Specified by:

getSignature in interface BeliefBase

Returns:

the signature of the language of this knowledge base.

asDungTheory

public DungTheory asDungTheory()

Returns:

a Dung Theory derived from this ABA theory

toString

public java.lang.String toString()

Specified by:

toString in interface BeliefBase

Overrides:

toString in class java.lang.Object