Consider the following premises. There is at least one x_8 for which x_8 will work if and only if x_8 is a carpenter. For all x_8, if x_8 were a taxi driver, then x_8 is a carpenter. For all x_8, x_8 is a doctor or x_8 will work. For all x_8, if x_8 were a doctor, then x_8 is a taxi driver. Can we infer the following from them? For all x_8, x_8 is not a carpenter.
 From the fact that there is at least one x_8 for which x_8 will work if and only if x_8 is a carpenter we can infer that there is at least one x_8 for which if x_8 works, then x_8 is a carpenter. From the fact that for all x_8, if x_8 were a doctor, then x_8 is a taxi driver, and that for all x_8, if x_8 were a taxi driver, then x_8 is a carpenter we can infer that for all x_8, if x_8 were a doctor, then x_8 is a carpenter. Finally, from the fact that for all x_8, if x_8 were a doctor, then x_8 is a carpenter, that there is at least one x_8 for which if x_8 works, then x_8 is a carpenter, and that for all x_8, x_8 is a doctor or x_8 will work we can infer that there is at least one x_8 for which x_8 is a carpenter, which contradicts that For all x_8, x_8 is not a carpenter. Therefore, the answer is no.