def on_upper_bound_changed(self):
        self.ui.spinBoxLowerBound.setMaximum(self.ui.spinBoxUpperBound.value() - 1)
        self.ui.spinBoxBoundaryNumber.setMaximum(math.ceil((self.ui.spinBoxUpperBound.value()
                                                            - self.ui.spinBoxLowerBound.value()) / 2))