Consider the following premises. For all x_1, if x_1 were a soldier, then x_1 is a cashier. It is sunny. John is not a cashier. For all x_1, if x_1 were a cashier, then x_1 is a soldier. Can we infer the following from them? John is a soldier.
 From the fact that for all x_1, if x_1 were a cashier, then x_1 is a soldier, and that for all x_1, if x_1 were a soldier, then x_1 is a cashier we can infer that for all x_1, x_1 is a cashier if and only if x_1 is a soldier. From the fact that for all x_1, x_1 is a cashier if and only if x_1 is a soldier we can infer that John is a cashier if and only if John is a soldier. Finally, from the fact that John is a cashier if and only if John is a soldier, and that John is not a cashier we can infer that John is not a soldier, which contradicts that John is a soldier. Therefore, the answer is no.