net.sf.tweety.logics.fol.syntax

Class Negation

java.lang.Object

net.sf.tweety.logics.fol.syntax.RelationalFormula

net.sf.tweety.logics.fol.syntax.FolFormula

net.sf.tweety.logics.fol.syntax.Negation

All Implemented Interfaces:

Formula, ClassicalFormula, ComplexLogicalFormula, Conjuctable, Disjunctable, Invertable, LogicStructure, ProbabilityAware, QuantifiedFormula, SimpleLogicalFormula

public class Negation
extends FolFormula

The classical negation of first-order logic.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private FolFormula	folFormula

Constructor Summary

Constructors

Constructor and Description
Negation(RelationalFormula formula)

Method Summary

Modifier and Type	Method and Description
Negation	clone() Creates a deep copy of this formula
FolFormula	collapseAssociativeFormulas() This method collapses all associative operations appearing in this term, e.g.
boolean	containsQuantifier() Checks whether this formula contains any quantification.
boolean	equals(java.lang.Object obj)
java.util.Set<FOLAtom>	getAtoms() Processes the set of all atoms which appear in this formula
FolFormula	getFormula()
java.util.Set<Functor>	getFunctors()
java.util.Set<? extends Predicate>	getPredicates() Processes the set of all predicates which appear in this formula
java.util.Set<Term<?>>	getTerms()
<C extends Term<?>> java.util.Set<C>	getTerms(java.lang.Class<C> cls) Processes the set containing all terms of type C.
java.util.Set<Variable>	getUnboundVariables()
int	hashCode()
boolean	isClosed() Checks whether this formula is closed, i.e.
boolean	isClosed(java.util.Set<Variable> boundVariables) Checks whether this formula is closed, i.e.
boolean	isDnf() Checks whether this formula is in disjunctive normal form.
boolean	isLiteral()
boolean	isWellBound() Checks whether this formula is well-bound, i.e.
boolean	isWellBound(java.util.Set<Variable> boundVariables) Checks whether this formula is well-bound, i.e.
Negation	substitute(Term<?> v, Term<?> t) Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.
FolFormula	toNnf() Makes the negation normal form of this formula.
java.lang.String	toString()

Methods inherited from class net.sf.tweety.logics.fol.syntax.FolFormula

combineWithAnd, combineWithOr, complement, getQuantifierVariables, getUniformProbability, toDnf

Methods inherited from class net.sf.tweety.logics.fol.syntax.RelationalFormula

allGroundInstances, allSubstitutions, containsTermsOfType, exchange, getPredicateCls, getSatisfactionRatio, getSignature, isGround, isWellFormed, substitute

Methods inherited from class java.lang.Object

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

Field Detail

folFormula

private FolFormula folFormula

Constructor Detail

Negation

public Negation(RelationalFormula formula)

Method Detail

getFormula

public FolFormula getFormula()

Specified by:

getFormula in interface QuantifiedFormula

Overrides:

getFormula in class RelationalFormula

Returns:

the formula which is quantified

getPredicates

public java.util.Set<? extends Predicate> getPredicates()

Description copied from interface: SimpleLogicalFormula

Processes the set of all predicates which appear in this formula

Returns:

all predicates that appear in this formula

getFunctors

public java.util.Set<Functor> getFunctors()

Specified by:

getFunctors in class RelationalFormula

Returns:

all functor that appear in this formula.

getAtoms

public java.util.Set<FOLAtom> getAtoms()

Description copied from interface: SimpleLogicalFormula

Processes the set of all atoms which appear in this formula

Specified by:

getAtoms in interface SimpleLogicalFormula

Specified by:

getAtoms in class RelationalFormula

Returns:

all atoms that appear in this formula.

containsQuantifier

public boolean containsQuantifier()

Description copied from interface: QuantifiedFormula

Checks whether this formula contains any quantification.

Returns:

"true" if this formula contains a quantification.

isClosed

public boolean isClosed()

Description copied from interface: QuantifiedFormula

Checks whether this formula is closed, i.e. whether every variables occurring in the formula is bound by a quantifier.

Returns:

"true" if this formula is closed, "false" otherwise.

substitute

public Negation substitute(Term<?> v,
                           Term<?> t)
                    throws java.lang.IllegalArgumentException

Description copied from class: RelationalFormula

Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula. NOTE: if "v" is a variable and bound to a quantifier then "v" is not substituted in that quantifiers inner formula.

Specified by:

substitute in interface ComplexLogicalFormula

Specified by:

substitute in class FolFormula

Parameters:

v - the term to be substituted.

t - the term to substitute.

Returns:

a formula where every occurrence of "v" is replaced by "t".

Throws:

java.lang.IllegalArgumentException - if "v" and "t" are of different sorts (NOTE: this exception is only thrown when "v" actually appears in this formula).

isClosed

public boolean isClosed(java.util.Set<Variable> boundVariables)

Description copied from interface: QuantifiedFormula

Checks whether this formula is closed, i.e. whether every variables occurring in the formula is bound by a quantifier. Every variable in "boundVariables" is already assumed to be bound.

Parameters:

boundVariables - the variables assumed to be bound.

Returns:

"true" if this formula is closed wrt. "boundVariables", "false" otherwise.

getUnboundVariables

public java.util.Set<Variable> getUnboundVariables()

Returns:

a set of of unbound variables

isWellBound

public boolean isWellBound()

Description copied from interface: QuantifiedFormula

Checks whether this formula is well-bound, i.e. whether no variable bound by a quantifier is again bound by another quantifier within the first quantifier's range.

Returns:

"true" if this formula is well-bound, "false" otherwise.

isWellBound

public boolean isWellBound(java.util.Set<Variable> boundVariables)

Description copied from interface: QuantifiedFormula

Checks whether this formula is well-bound, i.e. whether no variable bound by a quantifier is again bound by another quantifier within the first quantifier range. Every variable in "boundVariables" is assumed to be bound already.

Parameters:

boundVariables - the variables assumed to be bound.

Returns:

"true" if this formula is well-bound, "false" otherwise.

isLiteral

public boolean isLiteral()

Returns:

true if the formula represents a literal in the language or false otherwise

toString

public java.lang.String toString()

Specified by:

toString in class RelationalFormula

hashCode

public int hashCode()

Specified by:

hashCode in interface SimpleLogicalFormula

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Specified by:

equals in interface SimpleLogicalFormula

Overrides:

equals in class java.lang.Object

isDnf

public boolean isDnf()

Description copied from class: FolFormula

Checks whether this formula is in disjunctive normal form.

Specified by:

isDnf in class FolFormula

Returns:

"true" iff this formula is in disjunctive normal form.

toNnf

public FolFormula toNnf()

Description copied from class: FolFormula

Makes the negation normal form of this formula.

Specified by:

toNnf in class FolFormula

Returns:

the NNF of this formula

collapseAssociativeFormulas

public FolFormula collapseAssociativeFormulas()

Description copied from class: FolFormula

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 FolFormula

Returns:

the collapsed formula.

getTerms

public java.util.Set<Term<?>> getTerms()

Returns:

a set containing all terms of this logical structure

getTerms

public <C extends Term<?>> java.util.Set<C> getTerms(java.lang.Class<C> cls)

Description copied from interface: LogicStructure

Processes the set containing all terms of type C. This method uses the equals method of the given Class and therefore does not add terms which are sub classes of type C to the set.

Parameters:

cls - The Class structure containing type information about the searched term

Returns:

A set containing all terms of type C of this logical structure

clone

public Negation clone()

Description copied from interface: SimpleLogicalFormula

Creates a deep copy of this formula

Specified by:

clone in interface ComplexLogicalFormula

Specified by:

clone in interface SimpleLogicalFormula

Specified by:

clone in class FolFormula