Consider the following premises. For all y, y is a lawyer or y will make tea. For all y, if y were a lawyer, then y is a cashier. For all y, y will make tea if and only if y is a cashier. Can we infer the following from them? There is at least one y for which y is not a cashier.
 From the fact that for all y, y will make tea if and only if y is a cashier we can infer that for all y, if y makes tea, then y is a cashier. Finally, from the fact that for all y, if y were a lawyer, then y is a cashier, that for all y, if y makes tea, then y is a cashier, and that for all y, y is a lawyer or y will make tea we can infer that for all y, y is a cashier, which contradicts that There is at least one y for which y is not a cashier. Therefore, the answer is no.