Consider the following premises. For all x_10, if x_10 plays tennis, then x_10 is working. For all x_10, x_10 will play tennis if and only if x_10 is a mechanic. For all x_10, x_10 is a mechanic or x_10 is excited. There is at least one x_10 for which x_10 will not work. Can we infer the following from them? For all x_10, x_10 will play tennis if and only if x_10 is a mechanic.
That is one of the premises. Therefore, the answer is yes.