Package org.projog.core.predicate.builtin.reif

Class Dif

java.lang.Object

org.projog.core.predicate.AbstractSingleResultPredicate

org.projog.core.predicate.builtin.reif.Dif

All Implemented Interfaces:

KnowledgeBaseConsumer, PredicateFactory

public final class Dif
extends AbstractSingleResultPredicate

dif(X,Y) - enforces restriction that the two given terms are never equal.

If X and Y cannot unify then the goal succeeds. If X and Y are equal then the goal fails. If X and Y could unify then a restriction is added to prevent X and Y from unifying in the future.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	Dif.DifVariableAttribute
private static class	Dif.MyMap

Field Summary

Fields

Modifier and Type	Field	Description
private static Dif.DifVariableAttribute	ATTRIBUTE_KEY

Constructor Summary

Constructors

Constructor	Description
Dif()

Method Summary

Modifier and Type	Method	Description
private static void	appendAttribute(Variable v, Term attributeElement)
private Term	createTerm(java.util.List<? extends Term> args)
boolean	evaluate(Term arg1, Term arg2)

Methods inherited from class org.projog.core.predicate.AbstractSingleResultPredicate

evaluate, evaluate, evaluate, evaluate, evaluate, getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicates, getProjogListeners, getSpyPoints, getTermFormatter, init, isRetryable, setKnowledgeBase

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.projog.core.predicate.PredicateFactory

isAlwaysCutOnBacktrack

Field Detail

ATTRIBUTE_KEY

private static final Dif.DifVariableAttribute ATTRIBUTE_KEY

Constructor Detail

Dif

public Dif()

Method Detail

evaluate

public boolean evaluate(Term arg1,
                        Term arg2)

Overrides:

evaluate in class AbstractSingleResultPredicate

createTerm

private Term createTerm(java.util.List<? extends Term> args)

appendAttribute

private static void appendAttribute(Variable v,
                                    Term attributeElement)