 which is the formula required in Lewis 1968 to be able to move back to “necessarily, there are two worlds”, and which is the formula Brock and Rosen would need to derive if they were to show that Rosen’s (2) (or Brock’s equivalent) led the modal fictionalist to have to say that there are literally several worlds. The reason why (3L) does not imply (4L) is that it is not enough for there to be two worlds at a given world (V, let us call it) that there be existential quantification over two worlds within the scope of an existential quantifier committing us to V: the two worlds must also be “in” V, in the sense that the two place predicate “I” must hold between V and each of the worlds. This is what happens in (4L), but it does not happen in (3L), where there are two existential quantifiers over worlds in the scope of the outside universal quantifier, but where the worlds existentially quantified over are not asserted to be “in” any of the worlds w.