Consider the following premises. For all x_14, x_14 is a poet. There is at least one x_14 for which x_14 is a mechanic if and only if x_14 is a poet. Can we infer the following from them? For all x_14, neither x_14 is a mechanic nor x_14 is a taxi driver.
 From the fact that there is at least one x_14 for which x_14 is a mechanic if and only if x_14 is a poet we can infer that there is at least one x_14 for which if x_14 were a poet, then x_14 is a mechanic. From the fact that there is at least one x_14 for which if x_14 were a poet, then x_14 is a mechanic, and that for all x_14, x_14 is a poet we can infer that there is at least one x_14 for which x_14 is a mechanic. Finally, from the fact that there is at least one x_14 for which x_14 is a mechanic we can infer that there is at least one x_14 for which x_14 is a mechanic or x_14 is a taxi driver, which contradicts that For all x_14, neither x_14 is a mechanic nor x_14 is a taxi driver. Therefore, the answer is no.