code: public TraversalStep FORTH(String attributeName) {
  		TraversalExpression te = (TraversalExpression)this.astObject;
  		te.step(attributeName, 0);
  		TraversalStep ret = new TraversalStep(te);
  		QueryRecorder.recordInvocation(this, "FORTH", ret, QueryRecorder.literal(attributeName));
  		return ret;
  	}
docs: Traverse forward via an attribute
  @param attributeName
  @return