org.jacop.constraints

Class IfThenBool

java.lang.Object

org.jacop.constraints.DecomposedConstraint<Constraint>

org.jacop.constraints.Constraint

org.jacop.constraints.PrimitiveConstraint

org.jacop.constraints.IfThenBool

All Implemented Interfaces:

SatisfiedPresent, StoreAware

public class IfThenBool
extends PrimitiveConstraint

Constraint ( X => Y ) <=> Z.

Version:

4.9

Author:

Krzysztof Kuchcinski and Radoslaw Szymanek

Field Summary

Fields

Modifier and Type	Field and Description
IntVar	x It specifies variable x in constraint ( X => Y ) <=> Z.
IntVar	y It specifies variable y in constraint ( X => Y ) <=> Z.
IntVar	z It specifies variable z in constraint ( X => Y ) <=> Z.

Fields inherited from class org.jacop.constraints.PrimitiveConstraint

notConsistencyPruningEvents

Fields inherited from class org.jacop.constraints.Constraint

atomicExecution, consistencyPruningEvents, constraintScope, earlyTerminationOK, increaseWeight, numberId, scope, trace

Fields inherited from class org.jacop.constraints.DecomposedConstraint

queueIndex

Constructor Summary

Constructors

Constructor and Description
IfThenBool(IntVar x, IntVar y, IntVar z) It constructs constraint ( X => Y ) <=> Z.

Method Summary

Modifier and Type	Method and Description
String	checkInvariants() It checks invariants required by the constraint.
void	consistency(Store store) It is a (most probably incomplete) consistency function which removes the values from variables domains.
int	getDefaultConsistencyPruningEvent()
protected int	getDefaultNestedConsistencyPruningEvent()
protected int	getDefaultNestedNotConsistencyPruningEvent()
protected int	getDefaultNotConsistencyPruningEvent()
void	notConsistency(Store store) It makes pruning in such a way that constraint is notConsistent.
boolean	notSatisfied() It checks if constraint would be always not satisfied.
boolean	satisfied() It checks if the constraint is satisfied.
String	toString() It produces a string representation of a constraint state.

Methods inherited from class org.jacop.constraints.PrimitiveConstraint

getNestedPruningEvent, getNotConsistencyPruningEvent, impose, include, setNotConsistencyPruningEvent

Methods inherited from class org.jacop.constraints.Constraint

afc, arguments, cleanAfterFailure, decompose, getConsistencyPruningEvent, getGuideConstraint, getGuideValue, getGuideVariable, grounded, grounded, id, impose, imposeDecomposition, increaseWeight, intArrayToString, long2int, numberArgs, queueVariable, removeConstraint, requiresMonotonicity, setConsistencyPruningEvent, setConstraintScope, setScope, setScope, setScope, setScope, setScope, setWatchedVariableGrounded, supplyGuideFeedback, updateAFC, watchedVariableGrounded

Methods inherited from class org.jacop.constraints.DecomposedConstraint

auxiliaryVariables, checkInput, checkInput, checkInputForDuplication, checkInputForDuplicationSkipSingletons, checkInputForNullness, checkInputForNullness, checkInputForNullness, derivative, getDubletonsSkipSingletons, imposeDecomposition

Methods inherited from class java.lang.Object

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

Field Detail

x

public IntVar x

It specifies variable x in constraint ( X => Y ) <=> Z.

y

public IntVar y

It specifies variable y in constraint ( X => Y ) <=> Z.

z

public IntVar z

It specifies variable z in constraint ( X => Y ) <=> Z.

Constructor Detail

IfThenBool

public IfThenBool(IntVar x,
                  IntVar y,
                  IntVar z)

It constructs constraint ( X => Y ) <=> Z.

Parameters:

x - variable x.

y - variable y.

z - variable z.

Method Detail

checkInvariants

public String checkInvariants()

It checks invariants required by the constraint. Namely that boolean variables have boolean domain.

Returns:

the string describing the violation of the invariant, null otherwise.

consistency

public void consistency(Store store)

Description copied from class: Constraint

It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.

Specified by:

consistency in class Constraint

Parameters:

store - constraint store within which the constraint consistency is being checked.

getDefaultNestedConsistencyPruningEvent

protected int getDefaultNestedConsistencyPruningEvent()

Overrides:

getDefaultNestedConsistencyPruningEvent in class PrimitiveConstraint

getDefaultNestedNotConsistencyPruningEvent

protected int getDefaultNestedNotConsistencyPruningEvent()

Overrides:

getDefaultNestedNotConsistencyPruningEvent in class PrimitiveConstraint

getDefaultNotConsistencyPruningEvent

protected int getDefaultNotConsistencyPruningEvent()

Specified by:

getDefaultNotConsistencyPruningEvent in class PrimitiveConstraint

getDefaultConsistencyPruningEvent

public int getDefaultConsistencyPruningEvent()

Specified by:

getDefaultConsistencyPruningEvent in class Constraint

notConsistency

public void notConsistency(Store store)

Description copied from class: PrimitiveConstraint

It makes pruning in such a way that constraint is notConsistent. It removes values which always belong to a solution.

Specified by:

notConsistency in class PrimitiveConstraint

Parameters:

store - the constraint store in which context the notConsistency technique is evaluated.

notSatisfied

public boolean notSatisfied()

Description copied from class: PrimitiveConstraint

It checks if constraint would be always not satisfied.

Specified by:

notSatisfied in class PrimitiveConstraint

Returns:

true if constraint must be notSatisfied, false otherwise.

satisfied

public boolean satisfied()

Description copied from interface: SatisfiedPresent

It checks if the constraint is satisfied. It can return false even if constraint is satisfied but not all variables in its scope are grounded. It needs to return true if all variables in its scope are grounded and constraint is satisfied.

Implementations of this interface for constraints that are not PrimitiveConstraint may require constraint imposition and consistency check as a requirement to work correctly.

Returns:

true if constraint is possible to verify that it is satisfied.

toString

public String toString()

Description copied from class: Constraint

It produces a string representation of a constraint state.

Overrides:

toString in class Constraint