Consider the following premises. For all y_3, y_3 is a cashier or y_3 is not a lawyer. There is at least one y_3 for which if y_3 were a cashier, then y_3 is a lawyer. Can we infer the following from them? There is at least one y_3 for which if y_3 were a cashier, then y_3 is a lawyer.
That is one of the premises. Therefore, the answer is yes.