What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y_1, y_1 will take a plane or y_1 will not sleep. For all y_1, y_1 will sleep or y_1 will not take a plane.
For all y_1, if y_1 sleeps, then y_1 is taking a plane. For all y_1, if y_1 takes a plane, then y_1 is sleeping.