code: public RElement<RElement<?>> evalPredicate(Concatenator P) {
  		CollectExpression cx = CFactory.getRootCollectExpression(P);
  		if (cx != null) {
  			return resultOfCollection(cx);
  		}
  		
  		ReturnExpression rx = getReturnExpression();
  		ReturnBoolean bool = new ReturnBoolean();
  		PredicateExpression px = (PredicateExpression) APIObjectAccess.getAstNode(P);
  		bool.setPredicateExpression(px);
  		rx.setReturnValue(bool);
  		RElement<RElement<?>> ret = new RElement<RElement<?>>(rx);
  		return ret;
  	}
docs: <div color='red' style="font-size:24px;color:red"><b><i><u>JCYPHER</u></i></b></div>
  <div color='red' style="font-size:18px;color:red"><i>return the result of evaluating a Predicate Expression (<b>true</b> or <b>false</b>)</i></div>
  <div color='red' style="font-size:18px;color:red"><i>Use Factory Class <b>P</b> to create a Predicate Expressions</i></div>
  <div color='red' style="font-size:18px;color:red"><i>e.g. ...<b>evalPredicate(P.valueOf(a.property("age")).GT(30))</b></i></div>
  <br/>