 A third strategy involves employment of an inequality that can be shown to be violated without knowledge of the absolute value of the probabilities involved. This eliminates the need for untestable auxiliary assumptions. An inequality suitable for this purpose was first derived by Clauser and Horne (1974) (henceforth CH). The set-up is as before, with the exception that each analyzer will have only one output channel, and the eventualities to be considered are detection and non-detection. We want an inequality expressed in terms of probabilities of detection alone. The same sort of reasoning that leads to the CHSH inequality yields the CH Inequality: