Consider the following premises. For all x_1, x_1 will not play squash. For all x_1, if x_1 makes tea, then x_1 is playing squash. For all x_1, x_1 is a taxi driver if and only if x_1 will make tea. Can we infer the following from them? For all x_1, x_1 is not a taxi driver.
 From the fact that for all x_1, if x_1 makes tea, then x_1 is playing squash, and that for all x_1, x_1 will not play squash we can infer that for all x_1, x_1 will not make tea. Finally, from the fact that for all x_1, x_1 is a taxi driver if and only if x_1 will make tea, and that for all x_1, x_1 will not make tea we can infer that for all x_1, x_1 is not a taxi driver. Therefore, the answer is yes.