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 is a bartender if and only if y_1 will climb a mountain. For all y_1, y_1 is not a bartender. William is sleeping if and only if Michael is climbing a mountain.
If William sleeps, then Michael is climbing a mountain. If Michael climbs a mountain, then William is sleeping. For all y_1, if y_1 were a bartender, then y_1 is climbing a mountain. For all y_1, if y_1 climbs a mountain, then y_1 is a bartender. For all y_1, y_1 will not climb a mountain.