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.

Constructor Summary

Constructors

Constructor and Description
Dif()

Method Summary

Modifier and Type	Method and Description
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

Constructor Detail

Dif

public Dif()

Method Detail

evaluate

public boolean evaluate(Term arg1,
                        Term arg2)

Overrides:

evaluate in class AbstractSingleResultPredicate