Axiom 3 corresponds to the additivity axiom in probabilities. The laws thus derived yield finite additivity of probability, but not countable additivity. Therefore, by contraposition, a necessary condition for unit-treatment additivity is that the variance is constant. The assumption of unit treatment additivity was enunciated in experimental design by Kempthorne and Cox. Dilute solutions follow Kohlrausch's Laws of concentration dependence and additivity of ionic contributions. Then it is easy to verify that reciprocity, independence and additivity hold. It is further described in Heat of formation group additivity. Comonotonicity is also related to the comonotonic additivity of the Choquet integral. The condition required for additivity is preferential independence. Clearly it is important to identify which kind of additivity is being used. However, many "consequences" of treatment-unit additivity can be falsified. This can be shown using the additivity property of measures. The effect of drugs can be described with Loewe additivity. In fact, these are the first three cumulants and all cumulants share this additivity property. The additivity of Hilbert series shows that formula 41.