Consider the following premises. For all x_8, x_8 is a mechanic if and only if x_8 will play squash. For all x_8, x_8 will play squash. Can we infer the following from them? Sarah is a mechanic.
 From the fact that for all x_8, x_8 is a mechanic if and only if x_8 will play squash we can infer that for all x_8, if x_8 plays squash, then x_8 is a mechanic. From the fact that for all x_8, if x_8 plays squash, then x_8 is a mechanic, and that for all x_8, x_8 will play squash we can infer that for all x_8, x_8 is a mechanic. Finally, from the fact that for all x_8, x_8 is a mechanic we can infer that Sarah is a mechanic. Therefore, the answer is yes.