Consider the following premises. If Charles plays tennis, then Thomas is an artist. For all x_7, x_7 will play tennis if and only if x_7 will play squash. Thomas is not an artist. Can we infer the following from them? If we can, name the inference rule being used: Charles is not playing squash.
 From the fact that for all x_7, x_7 will play tennis if and only if x_7 will play squash we can infer that Charles is playing tennis if and only if Charles is playing squash via universal instantiation. From the fact that if Charles plays tennis, then Thomas is an artist, and that Thomas is not an artist we can infer that Charles is not playing tennis via modus tollens. Finally, from the fact that Charles is playing tennis if and only if Charles is playing squash, and that Charles is not playing tennis we can infer that Charles is not playing squash via biconditional elimination. Therefore, the answer is yes.