What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, z will drive a car if and only if z will play a game. For all z, z will play a game if and only if z will take a plane.
For all z, if z drives a car, then z is playing a game. For all z, if z plays a game, then z is taking a plane. For all z, if z plays a game, then z is driving a car. For all z, if z takes a plane, then z is playing a game.