Consider the following premises. There is at least one x_2 for which x_2 is a lawyer if and only if x_2 is a cashier. For all x_2, x_2 is a sailor. For all x_2, if x_2 were a cashier, then x_2 is not a sailor. Can we infer the following from them? If we can, name the inference rule being used: For all x_2, x_2 is a lawyer.
 From the fact that for all x_2, if x_2 were a cashier, then x_2 is not a sailor, and that for all x_2, x_2 is a sailor we can infer that for all x_2, x_2 is not a cashier via universal modus tollens. Finally, from the fact that there is at least one x_2 for which x_2 is a lawyer if and only if x_2 is a cashier, and that for all x_2, x_2 is not a cashier we can infer that there is at least one x_2 for which x_2 is not a lawyer via existential biconditional elimination, which contradicts that For all x_2, x_2 is a lawyer. Therefore, the answer is no.