Package net.sf.tweety.logics.pl.semantics

Class PriestWorld

java.lang.Object

net.sf.tweety.commons.AbstractInterpretation<PlBeliefSet,PlFormula>

net.sf.tweety.logics.pl.semantics.PriestWorld

All Implemented Interfaces:

Interpretation<PlBeliefSet,PlFormula>

public class PriestWorld
extends AbstractInterpretation<PlBeliefSet,PlFormula>

A three-valued interpretation for propositional logic from Priest's three valued logic (3VL) [Priest, G.: Logic of paradox. Journal of Philosophical Logic 8, 219-241 (1979)]. Every proposition gets one of three truth values: true, false, both.

Author:

Matthias Thimm

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PriestWorld.TruthValue	The three truth values.

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.Map<Proposition,PriestWorld.TruthValue>	values	The truth values of the propositions.

Constructor Summary

Constructors

Constructor	Description
PriestWorld()	Creates a new world where all propositions get the truth value FALSE.

Method Summary

Modifier and Type	Method	Description
PriestWorld.TruthValue	get(Proposition p)	Returns the truth value of the given proposition.
java.util.Collection<Proposition>	getBinarybase()	Returns the binary base of this world, i.e.
java.util.Collection<Proposition>	getConflictbase()	Returns the conflict base of this world, i.e.
boolean	satisfies(PlBeliefSet beliefBase)	Checks whether this interpretation satisfies the given knowledge base.
boolean	satisfies(PlFormula formula)	Checks whether this interpretation satisfies the given formula.
PriestWorld.TruthValue	satisfies3VL(PlFormula formula)	Determines the 3-valued truth value of the given formula.
void	set(Proposition p, PriestWorld.TruthValue val)	Sets the value of the given proposition.
java.lang.String	toString()

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

satisfies

Methods inherited from class java.lang.Object

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

Field Detail

values

private java.util.Map<Proposition,PriestWorld.TruthValue> values

The truth values of the propositions.

Constructor Detail

PriestWorld

public PriestWorld()

Creates a new world where all propositions get the truth value FALSE.

Method Detail

set

public void set(Proposition p,
                PriestWorld.TruthValue val)

Sets the value of the given proposition.

Parameters:

p - some proposition.

val - some truth value.

get

public PriestWorld.TruthValue get(Proposition p)

Returns the truth value of the given proposition.

Parameters:

p - a proposition

Returns:

a truth value.

satisfies

public boolean satisfies(PlFormula formula)
                  throws java.lang.IllegalArgumentException

Description copied from interface: Interpretation

Checks whether this interpretation satisfies the given formula.

Parameters:

formula - a formula .

Returns:

"true" if this interpretation satisfies the given formula.

Throws:

java.lang.IllegalArgumentException - if the formula does not correspond to the expected language.

satisfies3VL

public PriestWorld.TruthValue satisfies3VL(PlFormula formula)
                                    throws java.lang.IllegalArgumentException

Determines the 3-valued truth value of the given formula.

Parameters:

formula - some formula

Returns:

the 3-valued truth value of the formula.

Throws:

java.lang.IllegalArgumentException - if the formula is of unknown type

getBinarybase

public java.util.Collection<Proposition> getBinarybase()

Returns the binary base of this world, i.e. the set of all propositions which are assigned either to TRUE or FALSE.

Returns:

the binary base of this world.

getConflictbase

public java.util.Collection<Proposition> getConflictbase()

Returns the conflict base of this world, i.e. the set of all propositions which are assigned to BOTH.

Returns:

the conflict base of this world.

satisfies

public boolean satisfies(PlBeliefSet beliefBase)
                  throws java.lang.IllegalArgumentException

Description copied from interface: Interpretation

Checks whether this interpretation satisfies the given knowledge base.

Parameters:

beliefBase - a knowledge base.

Returns:

"true" if this interpretation satisfies the given knowledge base.

Throws:

java.lang.IllegalArgumentException - IllegalArgumentException if the knowledgebase does not correspond to the expected language.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object