What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all x_4, if x_4 were a bartender, then x_4 is running. For all x_4, x_4 is a bartender if and only if x_4 will drive a car.
For all x_4, if x_4 were a bartender, then x_4 is driving a car can be inferred via the universal biconditional elimination rule. For all x_4, if x_4 drives a car, then x_4 is a bartender can be inferred via the universal biconditional elimination rule.