What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_11, x_11 is an office clerk if and only if x_11 will take a plane. For all x_11, if x_11 listens to a song, then x_11 is an office clerk. For all x_11, x_11 will listen to a song or x_11 will take a plane. For all x_11, x_11 will drive a car.
For all x_11, if x_11 were an office clerk, then x_11 is taking a plane. For all x_11, if x_11 takes a plane, then x_11 is an office clerk.