net.sf.tweety.logics.el.syntax

Class ModalFormula

java.lang.Object

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

net.sf.tweety.logics.el.syntax.ModalFormula

All Implemented Interfaces:

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

Direct Known Subclasses:

Necessity, Possibility

public abstract class ModalFormula
extends RelationalFormula

This class models a modal formula, i.e. it encapsulates an modal operator and a formula (either a modal formula or a FolFormula).

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private RelationalFormula	formula The inner formula of this modal formula

Constructor Summary

Constructors

Constructor and Description
ModalFormula(RelationalFormula formula)

Method Summary

Modifier and Type	Method and Description
Conjunction	combineWithAnd(Conjuctable f) Returns a conjunction of this and the given formula.
Disjunction	combineWithOr(Disjunctable f)
RelationalFormula	complement()
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
RelationalFormula	getFormula() Returns the inner formula of this modal formula.
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<Variable>	getQuantifierVariables()
FolSignature	getSignature() Returns the signature of the language of 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()
Probability	getUniformProbability()
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	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.
RelationalFormula	substitute(Term<?> v, Term<?> t) Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.

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

allGroundInstances, allSubstitutions, clone, containsTermsOfType, exchange, getPredicateCls, getSatisfactionRatio, isGround, isWellFormed, substitute, toString

Methods inherited from class java.lang.Object

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

Field Detail

formula

private RelationalFormula formula

The inner formula of this modal formula

Constructor Detail

ModalFormula

public ModalFormula(RelationalFormula formula)

Method Detail

getSignature

public FolSignature getSignature()

Description copied from interface: Formula

Returns the signature of the language of this formula.

Specified by:

getSignature in interface Formula

Overrides:

getSignature in class RelationalFormula

Returns:

the signature of the language of this formula.

getUniformProbability

public Probability getUniformProbability()

Specified by:

getUniformProbability in interface ProbabilityAware

Specified by:

getUniformProbability in class RelationalFormula

Returns:

this formula's probability in the uniform distribution.

getFormula

public RelationalFormula getFormula()

Returns the inner formula of this modal formula.

Specified by:

getFormula in interface QuantifiedFormula

Overrides:

getFormula in class RelationalFormula

Returns:

the inner formula of this modal formula.

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.

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.

combineWithAnd

public Conjunction combineWithAnd(Conjuctable f)

Description copied from interface: Conjuctable

Returns a conjunction of this and the given formula.

Specified by:

combineWithAnd in interface Conjuctable

Specified by:

combineWithAnd in class RelationalFormula

Parameters:

f - a formula to be combined with AND and this.

Returns:

a conjunction of this and the given formula.

combineWithOr

public Disjunction combineWithOr(Disjunctable f)

Specified by:

combineWithOr in interface Disjunctable

Specified by:

combineWithOr in class RelationalFormula

Parameters:

f - a formula to be combined with OR and this.

Returns:

a disjunction of this and the given formula.

complement

public RelationalFormula complement()

Specified by:

complement in interface Invertable

Specified by:

complement in class RelationalFormula

Returns:

the complement of this formula.

isLiteral

public boolean isLiteral()

Returns:

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

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

getQuantifierVariables

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

Returns:

a set containing all quantified variables

substitute

public RelationalFormula 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 RelationalFormula

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).

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