Consider the following premises. For all x_12, if x_12 were a cashier, then x_12 is a politician. There is at least one x_12 for which if x_12 were a mechanic, then x_12 is a politician. For all x_12, x_12 is a politician if and only if x_12 is a taxi driver. For all x_12, x_12 is a cashier or x_12 is a mechanic. Can we infer the following from them? For all x_12, x_12 is not a taxi driver.
 From the fact that for all x_12, if x_12 were a cashier, then x_12 is a politician, that there is at least one x_12 for which if x_12 were a mechanic, then x_12 is a politician, and that for all x_12, x_12 is a cashier or x_12 is a mechanic we can infer that there is at least one x_12 for which x_12 is a politician. From the fact that for all x_12, x_12 is a politician if and only if x_12 is a taxi driver we can infer that for all x_12, if x_12 were a politician, then x_12 is a taxi driver. Finally, from the fact that for all x_12, if x_12 were a politician, then x_12 is a taxi driver, and that there is at least one x_12 for which x_12 is a politician we can infer that there is at least one x_12 for which x_12 is a taxi driver, which contradicts that For all x_12, x_12 is not a taxi driver. Therefore, the answer is no.