Theorem 5.1  (Aumann &amp; Brandenburger 1995: Theorem A) Suppose that \(G\) is a 2-person strategic game, \((p_1,p_2)\) are conjectures for players 1 and 2, and \(\T\) is a type space for \(G\). If \((s,t)\) is a state in \(\T\) where for \(i=1,2\), \(t_i\) assigns probability 1 to the events (a) both players are rational (i.e., maximize expected utility), (b) the game is \(G\) and (c) for \(i=1,2\), player \(i\)’s conjecture is \(p_i\), then \((p_1, p_2)\) constitutes a Nash equilibrium.