Consider the following premises. For all x_3, if x_3 plays tennis, then x_3 is a cashier. For all x_3, if x_3 were a cashier, then x_3 is playing tennis. Can we infer the following from them? If we can, name the inference rule being used: For all x_3, if x_3 plays tennis, then x_3 is a cashier.
That is one of the premises. Therefore, the answer is yes.