What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x, if x plays a game, then x is listening to a song. For all x, if x listens to a song, then x is playing a game. For all x, if x listens to a song, then x is playing a game.
For all x, x will play a game if and only if x will listen to a song. For all x, x will play a game if and only if x will listen to a song. For all x, x will listen to a song if and only if x will play a game. For all x, x will listen to a song if and only if x will play a game.