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 is a server or y_3 will climb a mountain. There is at least one y_3 for which if y_3 were a server, then y_3 is a bartender. For all y_3, if y_3 climbs a mountain, then y_3 is a bartender. For all y_3, if y_3 were a bartender, then y_3 is a server.
For all y_3, if y_3 climbs a mountain, then y_3 is a server. There is at least one y_3 for which y_3 is a bartender. There is at least one y_3 for which y_3 is a server if and only if y_3 is a bartender. There is at least one y_3 for which y_3 is a bartender if and only if y_3 is a server.