if (hasPlus && !hasMinus) {
                WorkspaceEntry fallingSignalWork = signalPhaseData.getFallingSignalWork(driverRef);
                if (fallingSignalWork != null) {
                    result.add("there is " + signalRef + SignalTransition.Direction.PLUS
                            + " but no " + signalRef + SignalTransition.Direction.MINUS