Note on “The Value of Two-Person Zero-Sum Repeated Games the extensive case”

The purpose of this note is to extend the results of J. F.Mertens and S.Zamir, The Value of Two-Person Zero-Sum Repeated Games with Lack of Information on Both Sides (Intern. Journal of Game Theory,1, 39–64, 1971) to the case where both players are not necessarily informed of each other's pure strategy choices at each stage.