Consider the following premises. There is at least one x_6 for which if x_6 were a poet, then x_6 is a taxi driver. For all x_6, x_6 is a poet. For all x_6, if x_6 were a taxi driver, then x_6 is a poet. Can we infer the following from them? For all x_6, x_6 is not a taxi driver.
 From the fact that there is at least one x_6 for which if x_6 were a poet, then x_6 is a taxi driver, and that for all x_6, if x_6 were a taxi driver, then x_6 is a poet we can infer that there is at least one x_6 for which x_6 is a poet if and only if x_6 is a taxi driver. From the fact that there is at least one x_6 for which x_6 is a poet if and only if x_6 is a taxi driver we can infer that there is at least one x_6 for which if x_6 were a poet, then x_6 is a taxi driver. Finally, from the fact that there is at least one x_6 for which if x_6 were a poet, then x_6 is a taxi driver, and that for all x_6, x_6 is a poet we can infer that there is at least one x_6 for which x_6 is a taxi driver, which contradicts that For all x_6, x_6 is not a taxi driver. Therefore, the answer is no.