“…[26], [14], Appendix D of [20]) and has been applied to various problems stemming from mathematical finance, the most important example of which is the computation of the super hedging price of the American contingent claims [6,17,18,22]. Optimal stopping under Knightian uncertainty/nonlinear expectations/risk measures or the closely related controller-stopper-games have attracted a lot of attention in the recent years: [23,24,16,8,9,32,2,3,4,5,7,25]. In this literature, the set of probabilities is assumed to be dominated by a single probability or the controller is only allowed to influence the drift.…”