In a game with incomplete information, a player may have beliefs about
nature, about the other players' beliefs about nature, and so on, in
an infinite hierarchy. We generalize a construction of Mertens & Zamir
and show, that if nature is any Hausdorff space, and beliefs are regu
lar Borel probability measures, then the space of all such infinite hi
erarchies of the players is a product of nature and the types of every
player, where a type of a player is a belief about nature and the oth
er players' types.