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_3, x_3 is a cashier or x_3 is a nurse. For all x_3, x_3 is not a cashier. For all x_3, x_3 is an office clerk.
For all x_3, x_3 is a nurse can be inferred via the universal disjunctive syllogism rule.