Boris believes that "it is common belief among me and Alex that Bruce Jenner won a gold medal at the Montreal Olympics," while Alex believes that "it is common belief among me and Boris that Bruce Jenner won a silver medal at the Montreal Olympics."
(a) Construct a belief space in which the described situation is represented by a state of the world and indicate that state.
(b) Prove that, in any belief space in which the set of states of the world is a finite set and contains a state ω describing the situation in this exercise, ω is not contained in the support of the beliefs of either Boris or Alex, at any state of the world. In other words, ω ∉ supp(πi(ω" )) for any state of the world ω" , for i ∈ {Boris, Alex}.