On the dispensable role of time in games of perfect information

In Aumann (1995) and Aumann (1998), time is assumed implicitly in the description of games of perfect information, and it is part of the epistemic distinction between ex-ante and ex-post knowledge. We show that ex-post knowledge in these papers can be expressed by ex-ante knowledge and therefore epistemically, time is irrelevant to the analysis. Furthermore, we show that material rationality by weak dominance and by expectation can be expressed in terms of the timeless strategic form of the game. Time present and time past Are both perhaps present in time future, And time future contained in time past. T. S. Eliot, Burnt Norton—the Four Quartets