Package net.sf.tweety.logics.pl.syntax

Class Proposition

java.lang.Object

net.sf.tweety.logics.pl.syntax.PlFormula

net.sf.tweety.logics.pl.syntax.Proposition

All Implemented Interfaces:

Comparable<Proposition>, net.sf.tweety.commons.Formula, net.sf.tweety.logics.commons.syntax.interfaces.Atom, net.sf.tweety.logics.commons.syntax.interfaces.ClassicalFormula, net.sf.tweety.logics.commons.syntax.interfaces.Conjunctable, net.sf.tweety.logics.commons.syntax.interfaces.Disjunctable, net.sf.tweety.logics.commons.syntax.interfaces.Invertable, net.sf.tweety.logics.commons.syntax.interfaces.ProbabilityAware, net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

public class Proposition
extends PlFormula
implements net.sf.tweety.logics.commons.syntax.interfaces.Atom, Comparable<Proposition>

This class represents a simple proposition in propositional logic.

Author:

Matthias Thimm, Tim Janus

Nested Class Summary

Nested classes/interfaces inherited from interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

net.sf.tweety.logics.commons.syntax.interfaces.Atom.AtomImpl, net.sf.tweety.logics.commons.syntax.interfaces.Atom.RETURN_SET_PREDICATE

Constructor Summary

Constructors

Constructor	Description
Proposition()	Default-Ctor for dynamic instantiation
Proposition(String name)	Creates a new proposition of the given name.
Proposition(Proposition other)

Method Summary

Modifier and Type	Method	Description
void	addArgument(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> arg)
Proposition	clone()
PlFormula	collapseAssociativeFormulas()	This method collapses all associative operations appearing in this term, e.g.
int	compareTo(Proposition o)
boolean	equals(Object obj)
List<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>>	getArguments()
Set<Proposition>	getAtoms()
Set<PlFormula>	getLiterals()	Returns all literals, i.e.
Set<PossibleWorld>	getModels(PlSignature sig)	Returns the set of models of this formula wrt.
String	getName()
PlPredicate	getPredicate()
Set<PlPredicate>	getPredicates()
PlSignature	getSignature()
int	hashCode()
boolean	isComplete()
boolean	isLiteral()
int	numberOfOccurrences(Proposition p)	Returns the number of occurrences of the given proposition within this formula
PlFormula	replace(Proposition p, PlFormula f, int i)	Replaces the ith instance of the proposition p by f.
net.sf.tweety.logics.commons.syntax.interfaces.Atom.RETURN_SET_PREDICATE	setPredicate(net.sf.tweety.logics.commons.syntax.Predicate predicate)
Conjunction	toCnf()	This method returns this formula in conjunctive normal form (CNF).
PlFormula	toNnf()	This method returns this formula in negation normal form (NNF).
String	toString()
PlFormula	trim()	Removes duplicates (identical formulas) from conjunctions and disjunctions and removes duplicate negations.

Methods inherited from class net.sf.tweety.logics.pl.syntax.PlFormula

combineWithAnd, combineWithOr, complement, getModels, getPredicateCls, getPrimeImplicants, getUniformProbability, isClause, isConjunctiveClause, resolvableWith, resolveWith, toBlakeCanonicalForm, toDnf

Methods inherited from class java.lang.Object

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

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

getPredicateCls

Constructor Detail

Proposition

public Proposition()

Default-Ctor for dynamic instantiation

Proposition

public Proposition(String name)

Creates a new proposition of the given name.

Parameters:

name - the name of the proposition.

Proposition

public Proposition(Proposition other)

Method Detail

getName

public String getName()

Specified by:

getName in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

Returns:

the name of this proposition.

getPredicate

public PlPredicate getPredicate()

Specified by:

getPredicate in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

getPredicates

public Set<PlPredicate> getPredicates()

Specified by:

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

Specified by:

getPredicates in class PlFormula

toString

public String toString()

Overrides:

toString in class Object

collapseAssociativeFormulas

public PlFormula collapseAssociativeFormulas()

Description copied from class: PlFormula

This method collapses all associative operations appearing in this term, e.g. every a||(b||c) becomes a||b||c.

Specified by:

collapseAssociativeFormulas in class PlFormula

Returns:

the collapsed formula.

getSignature

public PlSignature getSignature()

Specified by:

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

Overrides:

getSignature in class PlFormula

hashCode

public int hashCode()

Specified by:

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

Specified by:

hashCode in class PlFormula

equals

public boolean equals(Object obj)

Specified by:

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

Specified by:

equals in class PlFormula

toNnf

public PlFormula toNnf()

Description copied from class: PlFormula

This method returns this formula in negation normal form (NNF). A formula is in NNF iff negations occur only directly in front of a proposition.

Specified by:

toNnf in class PlFormula

Returns:

the formula in NNF.

clone

public Proposition clone()

Specified by:

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

Specified by:

clone in class PlFormula

trim

public PlFormula trim()

Description copied from class: PlFormula

Removes duplicates (identical formulas) from conjunctions and disjunctions and removes duplicate negations. Simplifies equivalences and implications with equivalent formulas (A=>A, A<=>A) to tautologies.

Specified by:

trim in class PlFormula

Returns:

an equivalent formula without duplicates.

addArgument

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

Specified by:

addArgument in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

getArguments

public List<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> getArguments()

Specified by:

getArguments in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

isComplete

public boolean isComplete()

Specified by:

isComplete in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

getAtoms

public Set<Proposition> getAtoms()

Specified by:

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

Specified by:

getAtoms in class PlFormula

isLiteral

public boolean isLiteral()

Specified by:

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

Overrides:

isLiteral in class PlFormula

getLiterals

public Set<PlFormula> getLiterals()

Description copied from class: PlFormula

Returns all literals, i.e. all formulas of the form "a" or "!a" where "a" is a proposition, that appear in this formula.

Specified by:

getLiterals in class PlFormula

Returns:

all literals appearing in this formula.

setPredicate

public net.sf.tweety.logics.commons.syntax.interfaces.Atom.RETURN_SET_PREDICATE setPredicate(net.sf.tweety.logics.commons.syntax.Predicate predicate)

Specified by:

setPredicate in interface net.sf.tweety.logics.commons.syntax.interfaces.Atom

compareTo

public int compareTo(Proposition o)

Specified by:

compareTo in interface Comparable<Proposition>

toCnf

public Conjunction toCnf()

Description copied from class: PlFormula

This method returns this formula in conjunctive normal form (CNF). A formula is in CNF iff it is a conjunction of disjunctions and in NNF.

Specified by:

toCnf in class PlFormula

Returns:

the formula in CNF.

numberOfOccurrences

public int numberOfOccurrences(Proposition p)

Description copied from class: PlFormula

Returns the number of occurrences of the given proposition within this formula

Specified by:

numberOfOccurrences in class PlFormula

Parameters:

p - some proposition

Returns:

the number of occurrences of the given proposition within this formula

replace

public PlFormula replace(Proposition p,
                         PlFormula f,
                         int i)

Description copied from class: PlFormula

Replaces the ith instance of the proposition p by f.

Specified by:

replace in class PlFormula

Parameters:

p - some proposition

f - some formula

i - the index of the proposition

Returns:

a new formula with the ith instance of the proposition p replaced by f.

getModels

public Set<PossibleWorld> getModels(PlSignature sig)

Description copied from class: PlFormula

Returns the set of models of this formula wrt. the given signature.

Specified by:

getModels in class PlFormula

Parameters:

sig - some propositional signature

Returns:

the set of models of this formula wrt. the given signature.