 In “chancy” situations, possibility theory can only make very course-grained distinctions. Since Sophia is certain that the Euro coin will not land on its edge \(\Pi(H\cup T)=\Pi(W)\), she must have \(\Pi(H)=1\) or \(\Pi(T)=1.\) The most natural way to model her attitude is to set \(\Pi(H)=\Pi(T)=1\). There is no way of expressing a partial attitude towards both heads and tails, since these are both maximally possible.