What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Mary is listening to a song if and only if Susan is fast. If Susan plays a game, then Mary is listening to a song. For all x_8, x_8 will play a game or x_8 is fast.
If Mary listens to a song, then Susan is fast. If Susan were fast, then Mary is listening to a song.