Consider the following premises. For all x_6, if x_6 were a cashier, then x_6 is bored. There is at least one x_6 for which x_6 is a politician if and only if x_6 is bored. For all x_6, if x_6 were a politician, then x_6 is a cashier. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_6 for which x_6 is a politician if and only if x_6 is bored.
That is one of the premises. Therefore, the answer is yes.