Consider the following premises. For all x_9, x_9 is a carpenter or x_9 is a soldier. There is at least one x_9 for which x_9 is a cashier if and only if x_9 is a carpenter. For all x_9, x_9 is a cashier if and only if x_9 is a soldier. Can we infer the following from them? For all x_9, x_9 is not a cashier.
 From the fact that there is at least one x_9 for which x_9 is a cashier if and only if x_9 is a carpenter we can infer that there is at least one x_9 for which if x_9 were a carpenter, then x_9 is a cashier. From the fact that for all x_9, x_9 is a cashier if and only if x_9 is a soldier we can infer that for all x_9, if x_9 were a soldier, then x_9 is a cashier. Finally, from the fact that there is at least one x_9 for which if x_9 were a carpenter, then x_9 is a cashier, that for all x_9, if x_9 were a soldier, then x_9 is a cashier, and that for all x_9, x_9 is a carpenter or x_9 is a soldier we can infer that there is at least one x_9 for which x_9 is a cashier, which contradicts that For all x_9, x_9 is not a cashier. Therefore, the answer is no.