Consider the following premises. For all x_12, if x_12 were bored, then x_12 is working. If Mary plays squash, then Linda is working. If Linda works, then Mary is playing squash. Mary is not playing squash. Can we infer the following from them? If we can, name the inference rule being used: Linda is not bored.
 From the fact that for all x_12, if x_12 were bored, then x_12 is working we can infer that if Linda were bored, then Linda is working via universal instantiation. From the fact that if Linda works, then Mary is playing squash, and that if Mary plays squash, then Linda is working we can infer that Linda is working if and only if Mary is playing squash via biconditional introduction. From the fact that Linda is working if and only if Mary is playing squash, and that Mary is not playing squash we can infer that Linda is not working via biconditional elimination. Finally, from the fact that if Linda were bored, then Linda is working, and that Linda is not working we can infer that Linda is not bored via modus tollens. Therefore, the answer is yes.