 Intuitively, (*) is 10% likely: of those over 10 cm, one is under 15 cm and nine are not. But on Stalnaker’s theory, (*) appears to be 91% likely: it’s 90% likely that it is not over 10 cm, in which case, in the world most similar to the actual world in which it is over 10 cm, it is 11 cm, i.e. less than 15 cm. And we add another 1% for the case in which it is 11 cm, hence under 15 cm.