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