 played again on a structure with two elements 0 and 1. Player \(\exists\) can win as follows. For \(z\) she chooses the same as player \(\forall\) chose for \(x\); then for \(y\) she chooses the same as she chose for \(z\). This winning strategy works only because in this game \(\exists\) can refer back to her own previous choices. She would have no winning strategy if the third quantifier was \((\exists y/xz)\), again because any Skolem function for this quantifier would have to be constant. The way that \(\exists\) passes information to herself by referring to her previous choice is an example of the phenomenon of signalling. John von Neumann and Oskar Morgenstern illustrated it with the example of Bridge, where a single player consists of two partners who have to share information by using their public moves to signal to each other.