net.sf.tweety.arg.dung

Class AbstractExtensionReasoner

java.lang.Object

net.sf.tweety.commons.Reasoner

net.sf.tweety.arg.dung.AbstractExtensionReasoner

Direct Known Subclasses:

AdmissibleReasoner, CF2Reasoner, CompleteReasoner, ConflictFreeReasoner, GroundReasoner, IdealReasoner, PreferredReasoner, SccCompleteReasoner, SemiStableReasoner, StableReasoner, StageReasoner

public abstract class AbstractExtensionReasoner
extends Reasoner

This class models an abstract extension reasoner used for Dung theories.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Set<Extension>	extensions The extensions this reasoner bases upon.
private int	inferenceType The type of inference for this reasoner, either sceptical or credulous.

Constructor Summary

Constructors

Constructor and Description
AbstractExtensionReasoner(BeliefBase beliefBase) Creates a new reasoner for the given knowledge base using sceptical inference.
AbstractExtensionReasoner(BeliefBase beliefBase, int inferenceType) Creates a new reasoner for the given knowledge base.

Method Summary

Modifier and Type	Method and Description
protected abstract java.util.Set<Extension>	computeExtensions() Computes the extensions this reasoner bases upon.
java.util.Set<Extension>	getExtensions() Returns the extensions this reasoner bases upon.
int	getInferenceType() Returns the inference type of this reasoner.
PlBeliefSet	getPropositionalCharacterisation() Creates a propositional representation of the set of labelings of the underlying Dung theory that are consistent with the given semantics.
protected abstract PlBeliefSet	getPropositionalCharacterisationBySemantics(java.util.Map<Argument,Proposition> in, java.util.Map<Argument,Proposition> out, java.util.Map<Argument,Proposition> undec) Returns the semantic-specific propositional characterization of the underlying Dung theory, see getPropositionalCharacterisation.
static AbstractExtensionReasoner	getReasonerForSemantics(BeliefBase beliefBase, Semantics semantics, int inferenceType) Creates a reasoner for the given semantics.
Answer	query(Formula query) This method determines the answer of the given query wrt.

Methods inherited from class net.sf.tweety.commons.Reasoner

getKnowledgeBase

Methods inherited from class java.lang.Object

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

Field Detail

extensions

private java.util.Set<Extension> extensions

The extensions this reasoner bases upon.

inferenceType

private int inferenceType

The type of inference for this reasoner, either sceptical or credulous.

Constructor Detail

AbstractExtensionReasoner

public AbstractExtensionReasoner(BeliefBase beliefBase,
                                 int inferenceType)

Creates a new reasoner for the given knowledge base.

Parameters:

beliefBase - The knowledge base for this reasoner.

inferenceType - The inference type for this reasoner.

AbstractExtensionReasoner

public AbstractExtensionReasoner(BeliefBase beliefBase)

Creates a new reasoner for the given knowledge base using sceptical inference.

Parameters:

beliefBase - The knowledge base for this reasoner.

Method Detail

getReasonerForSemantics

public static AbstractExtensionReasoner getReasonerForSemantics(BeliefBase beliefBase,
                                                                Semantics semantics,
                                                                int inferenceType)

Creates a reasoner for the given semantics.

Parameters:

beliefBase - some Dung theory

semantics - a semantics

inferenceType - an inference type

Returns:

a reasoner for the given Dung theory, inference type, and semantics

query

public Answer query(Formula query)

Description copied from class: Reasoner

This method determines the answer of the given query wrt. to the given knowledge base.

Specified by:

query in class Reasoner

Parameters:

query - a query.

Returns:

the answer to the query.

getPropositionalCharacterisation

public PlBeliefSet getPropositionalCharacterisation()

Creates a propositional representation of the set of labelings of the underlying Dung theory that are consistent with the given semantics. This means that for every argument A in the theory three propositions are created: in_A, out_A, undec_A. For every attack A->B the formula "in_A => out_B" is added to the belief set. Depending on the actual semantics further propositional formulas are added. For example, for any admissable semantics and unattacked argument A, the constraint "\top=>in_A" is added; another constraint added for admissable semantics is, given any argument A and attackers B1...BN, add the constraint in_A => out_B1 ^ ... ^ out_BN.

Returns:

a propositional belief set.

getPropositionalCharacterisationBySemantics

protected abstract PlBeliefSet getPropositionalCharacterisationBySemantics(java.util.Map<Argument,Proposition> in,
                                                                           java.util.Map<Argument,Proposition> out,
                                                                           java.util.Map<Argument,Proposition> undec)

Returns the semantic-specific propositional characterization of the underlying Dung theory, see getPropositionalCharacterisation.

Parameters:

in - propositional variables of in arguments.

out - propositional variables of out arguments.

undec - propositional variables of undec arguments.

Returns:

the semantic-specific propositional characterization of the underlying Dung theory, see getPropositionalCharacterisation.

getExtensions

public java.util.Set<Extension> getExtensions()

Returns the extensions this reasoner bases upon.

Returns:

the extensions this reasoner bases upon.

getInferenceType

public int getInferenceType()

Returns the inference type of this reasoner.

Returns:

the inference type of this reasoner.

computeExtensions

protected abstract java.util.Set<Extension> computeExtensions()

Computes the extensions this reasoner bases upon.

Returns:

A set of extensions.