 One challenge posed by Curry’s paradox is to pinpoint what goes wrong in the foregoing informal argument for  (P),  (Q) or the like. But starting with Curry’s initial presentation in Curry 1942b (see the supplementary document on   Curry on Curry’s Paradox), discussion of Curry’s paradox has usually had a different focus. It has concerned various formal systems —most often set theories or theories of truth. In this setting what poses the paradox is a proof that the system has a particular feature. Typically, the feature at issue is triviality. A theory is said to be trivial, or absolutely inconsistent, when it affirms every claim that is expressible in the language of the  theory.[2] 