of another proposition Y, then X also provides evidence in favor of any proposition that is logically equivalent to Y. Realistically, the set of ravens is finite. The set of non-black things is either infinite or beyond human enumeration. To confirm the statement 'All ravens are black', it would be necessary to observe all ravens. This is difficult but possible. To confirm the statement 'All non-black things are non-ravens', it would be necessary to examine all non-black things. This is not possible. Observing a black raven could be considered a finite amount of confirmatory evidence, but observing a non-black non-raven would be an infinitesimal amount of evidence. The paradox shows that Nicod's criterion and Hempel's equivalence condition are not mutually consistent. A resolution to the paradox must reject at least one out of: negative instances having no influence (!PC), equivalence condition (EC), or, validation by positive instances (NC). A satisfactory resolution should also explain why there naively appears to be a paradox. Solutions that accept the paradoxical conclusion can do this by presenting a proposition that we intuitively know to be false but that is easily confused with (PC), while solutions that reject (EC) or (NC) should present a proposition that we intuitively know to be true but that is easily confused with (EC) or (NC). Accepting non-ravens as relevant Although this conclusion of the paradox seems counter-intuitive, some approaches accept that observations of (coloured) non-ravens can in fact constitute valid evidence in support for hypotheses about (the universal blackness of) ravens. Hempel's resolution Hempel himself accepted the paradoxical conclusion, arguing that the reason the result appears paradoxical is that we possess prior information without which the observation of a non-black non-raven would indeed provide evidence that all ravens are black. He illustrates this with the example of the generalization "All sodium salts burn yellow," and asks us to consider the observation that occurs when somebody holds a piece of pure ice in a colorless flame that does not turn yellow: Standard Bayesian solution One of the most popular proposed resolutions is to accept the conclusion that the observation of a green apple provides evidence that all ravens are black but to argue that the amount of confirmation provided is very small, due to the large discrepancy between the number of ravens and the number of non-black objects. According to this resolution, the conclusion appears paradoxical because we intuitively estimate