net.sf.tweety.logics.fol.syntax

Class RelationalFormula

java.lang.Object

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

All Implemented Interfaces:

net.sf.tweety.commons.Formula, net.sf.tweety.logics.commons.syntax.interfaces.ClassicalFormula, net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula, net.sf.tweety.logics.commons.syntax.interfaces.Conjuctable, net.sf.tweety.logics.commons.syntax.interfaces.Disjunctable, net.sf.tweety.logics.commons.syntax.interfaces.Invertable, net.sf.tweety.logics.commons.syntax.interfaces.LogicStructure, net.sf.tweety.logics.commons.syntax.interfaces.ProbabilityAware, net.sf.tweety.logics.commons.syntax.interfaces.QuantifiedFormula, net.sf.tweety.logics.commons.syntax.interfaces.SimpleLogicalFormula

Direct Known Subclasses:

FolFormula

public abstract class RelationalFormula
extends Object
implements net.sf.tweety.logics.commons.syntax.interfaces.ClassicalFormula, net.sf.tweety.logics.commons.syntax.interfaces.QuantifiedFormula

This interface models a relational formula, i.e. a formula that is build on a first-order signature.

Author:

Matthias Thimm, Tim Janus

Constructor Summary

Constructors

Constructor and Description
RelationalFormula()

Method Summary

Modifier and Type	Method and Description
Set<RelationalFormula>	allGroundInstances(Set<net.sf.tweety.logics.commons.syntax.Constant> constants) Computes all ground instances of this relational formula wrt.
Set<Map<net.sf.tweety.logics.commons.syntax.Variable,net.sf.tweety.logics.commons.syntax.interfaces.Term<?>>>	allSubstitutions(Collection<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> terms) Computes all possible substitutions, i.e.
abstract RelationalFormula	clone()
abstract Conjunction	combineWithAnd(net.sf.tweety.logics.commons.syntax.interfaces.Conjuctable formula)
abstract Disjunction	combineWithOr(net.sf.tweety.logics.commons.syntax.interfaces.Disjunctable formula)
abstract RelationalFormula	complement()
<C extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> boolean	containsTermsOfType(Class<C> cls)
RelationalFormula	exchange(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t) Substitutes all occurrences of term "v" in this formula by term "t" and at the same time replaces all occurrences of term "t" by term "v" and eventually returns the new formula.
abstract Set<FOLAtom>	getAtoms()
RelationalFormula	getFormula()
abstract Set<net.sf.tweety.logics.commons.syntax.Functor>	getFunctors()
Class<net.sf.tweety.logics.commons.syntax.Predicate>	getPredicateCls()
double	getSatisfactionRatio() Returns the ratio of worlds not satisfying this formula to worlds satisfying this formula.
FolSignature	getSignature()
abstract net.sf.tweety.math.probability.Probability	getUniformProbability()
boolean	isGround() Checks whether this formula is ground, i.e.
boolean	isWellFormed() Tests whether this formula is well-formed, i.e.
RelationalFormula	substitute(Map<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>,? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> map) Substitutes all occurrences of all terms "v" in map.keyset() in this formula by map.get(v) and returns the new formula. NOTE: variables bound to quantifiers are not substituted in their inner formulas even if they appear in the map.
abstract RelationalFormula	substitute(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v, net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t) Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.
abstract String	toString()

Methods inherited from class java.lang.Object

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

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

containsQuantifier, getQuantifierVariables, getUnboundVariables, isClosed, isClosed, isWellBound, isWellBound

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

equals, getPredicates, hashCode, isLiteral

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

getTerms, getTerms

Constructor Detail

RelationalFormula

public RelationalFormula()

Method Detail

getPredicateCls

public Class<net.sf.tweety.logics.commons.syntax.Predicate> getPredicateCls()

Specified by:

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

getFormula

public RelationalFormula getFormula()

Specified by:

getFormula in interface net.sf.tweety.logics.commons.syntax.interfaces.QuantifiedFormula

getAtoms

public abstract Set<FOLAtom> getAtoms()

Specified by:

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

Returns:

all atoms that appear in this formula.

getFunctors

public abstract Set<net.sf.tweety.logics.commons.syntax.Functor> getFunctors()

Returns:

all functor that appear in this formula.

substitute

public abstract RelationalFormula substitute(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v,
                                             net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t)
                                      throws IllegalArgumentException

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 net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

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:

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

exchange

public RelationalFormula exchange(net.sf.tweety.logics.commons.syntax.interfaces.Term<?> v,
                                  net.sf.tweety.logics.commons.syntax.interfaces.Term<?> t)
                           throws IllegalArgumentException

Substitutes all occurrences of term "v" in this formula by term "t" and at the same time replaces all occurrences of term "t" by term "v" and eventually 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:

exchange in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Parameters:

v - a term.

t - a term.

Returns:

a new relational formula with both "v" and "t" exchanged.

Throws:

IllegalArgumentException - if "v" and "t" are of different sorts

substitute

public RelationalFormula substitute(Map<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>,? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> map)
                             throws IllegalArgumentException

Substitutes all occurrences of all terms "v" in map.keyset() in this formula by map.get(v) and returns the new formula.
NOTE: variables bound to quantifiers are not substituted in their inner formulas even if they appear in the map.

Specified by:

substitute in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Parameters:

map - a mapping defining which terms to be substituted.

Returns:

a formula where every term in map.keyset() has been replaced by map.get(v).

Throws:

IllegalArgumentException - if any term and its mapping are of different sorts (NOTE: this exception is only thrown when the variable actually appears in this formula).

allSubstitutions

public Set<Map<net.sf.tweety.logics.commons.syntax.Variable,net.sf.tweety.logics.commons.syntax.interfaces.Term<?>>> allSubstitutions(Collection<? extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> terms)
                                                                                                                               throws IllegalArgumentException

Computes all possible substitutions, i.e. maps from variables to terms, of unbound variables of this formula to terms in "terms".

Parameters:

terms - a set of terms.

Returns:

a set of maps from variables to terms.

Throws:

IllegalArgumentException - if there is an unbound variable in this formula for which there is no term in "terms" with the same sort.

allGroundInstances

public Set<RelationalFormula> allGroundInstances(Set<net.sf.tweety.logics.commons.syntax.Constant> constants)
                                          throws IllegalArgumentException

Computes all ground instances of this relational formula wrt. the given set of constants, i.e. every formula where each occurrence of some unbound variable is replaced by some constant.

Parameters:

constants - a set of constants

Returns:

a set of ground instances of this formula

Throws:

IllegalArgumentException - if there is an unbound variable in this formula for which there is no constant in "constants" with the same sort.

getSatisfactionRatio

public double getSatisfactionRatio()

Returns the ratio of worlds not satisfying this formula to worlds satisfying this formula.

Returns:

the ratio of worlds not satisfying this formula to worlds satisfying this formula.

getUniformProbability

public abstract net.sf.tweety.math.probability.Probability getUniformProbability()

Specified by:

getUniformProbability in interface net.sf.tweety.logics.commons.syntax.interfaces.ProbabilityAware

isGround

public boolean isGround()

Checks whether this formula is ground, i.e. whether there appears no variable in this formula.

Specified by:

isGround in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Returns:

"true" if this formula is ground.

isWellFormed

public boolean isWellFormed()

Tests whether this formula is well-formed, i.e. whether
- there are no two variables with the same name but different sort
- there are no two constants with the same name but different sort
- there are no two predicates with the same name but different arguments
- there are no two functors with the same name but different sort or arguments
- every atom is complete, i.e. has a complete list of arguments
- every functional term is complete, i.e. has a complete list of arguments
- no variable bound by a quantifier is again bound by another quantifier within the first quantifier range.
- every functor has arity greater zero (otherwise it should be modeled by a constant

Specified by:

isWellFormed in interface net.sf.tweety.logics.commons.syntax.interfaces.ComplexLogicalFormula

Returns:

"true" if this formula is well-formed

getSignature

public FolSignature getSignature()

Specified by:

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

containsTermsOfType

public <C extends net.sf.tweety.logics.commons.syntax.interfaces.Term<?>> boolean containsTermsOfType(Class<C> cls)

Specified by:

containsTermsOfType in interface net.sf.tweety.logics.commons.syntax.interfaces.LogicStructure

complement

public abstract RelationalFormula complement()

Specified by:

complement in interface net.sf.tweety.logics.commons.syntax.interfaces.Invertable

combineWithOr

public abstract Disjunction combineWithOr(net.sf.tweety.logics.commons.syntax.interfaces.Disjunctable formula)

Specified by:

combineWithOr in interface net.sf.tweety.logics.commons.syntax.interfaces.Disjunctable

combineWithAnd

public abstract Conjunction combineWithAnd(net.sf.tweety.logics.commons.syntax.interfaces.Conjuctable formula)

Specified by:

combineWithAnd in interface net.sf.tweety.logics.commons.syntax.interfaces.Conjuctable

toString

public abstract String toString()

Overrides:

toString in class Object

clone

public abstract RelationalFormula clone()

Specified by:

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

Specified by:

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

Overrides:

clone in class Object