Consider the following premises. There is at least one x_10 for which if x_10 were poor, then x_10 is a mechanic. For all x_10, if x_10 were a mechanic, then x_10 is poor. For all x_10, x_10 is a mechanic and x_10 is a carpenter. Can we infer the following from them? For all x_10, x_10 is a mechanic and x_10 is a carpenter.
That is one of the premises. Therefore, the answer is yes.