What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_15, x_15 will listen to a song or x_15 will not write a letter. For all x_15, x_15 is a bartender if and only if x_15 will listen to a song. There is at least one x_15 for which if x_15 were a bartender, then x_15 is listening to a song.
For all x_15, if x_15 writes a letter, then x_15 is listening to a song. For all x_15, if x_15 were a bartender, then x_15 is listening to a song. For all x_15, if x_15 listens to a song, then x_15 is a bartender.