Weak assumption and iterative admissibility

Brandenburger et al. (2008a) show that rationality and common assumption of rationality (RCAR) is impossible in a complete and continuous type structure. We show, by introducing an alternative notion of assumption, “weak assumption”, that rationality and common weak assumption of rationality (RCWAR) is possible in a complete and continuous type structure. This possibility result provides an epistemic characterization for iterative admissibility.