final PathLengthZero zeroOperator = new PathLengthZero(subject, object, allowedSubjects, allowedObjects);
memoryScan.addSucceedingOperator(new OperatorIDTuple(zeroOperator,0));
final Union union = new Union();
zeroOperator.addSucceedingOperator(new OperatorIDTuple(union,0));
startingOperator.addSucceedingOperator(new OperatorIDTuple(union,1));
final InMemoryDistinct distinct = new InMemoryDistinct();
union.addSucceedingOperator(new OperatorIDTuple(distinct,0));