What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y_3, y_3 will listen to a song if and only if y_3 is a taxi driver. For all y_3, y_3 will listen to a song or y_3 is not a taxi driver.
For all y_3, if y_3 were a taxi driver, then y_3 is listening to a song. For all y_3, if y_3 listens to a song, then y_3 is a taxi driver. For all y_3, if y_3 were a taxi driver, then y_3 is listening to a song.