Consider the following premises. If Karen were a taxi driver, then Charles is playing squash. It is not late or Karen is a taxi driver. For all x_13, if x_13 plays squash, then x_13 is a politician. If it is sunny, then Charles is a politician. It is late or it is sunny. Can we infer the following from them? If we can, name the inference rule being used: Charles is not a politician.
 From the fact that for all x_13, if x_13 plays squash, then x_13 is a politician we can infer that if Charles plays squash, then Charles is a politician via universal instantiation. From the fact that if Karen were a taxi driver, then Charles is playing squash, and that if Charles plays squash, then Charles is a politician we can infer that if Karen were a taxi driver, then Charles is a politician via transitivity. From the fact that it is late or it is sunny, and that it is not late or Karen is a taxi driver we can infer that it is sunny or Karen is a taxi driver via resolution. Finally, from the fact that if it is sunny, then Charles is a politician, that if Karen were a taxi driver, then Charles is a politician, and that it is sunny or Karen is a taxi driver we can infer that Charles is a politician via disjunction elimination, which contradicts that Charles is not a politician. Therefore, the answer is no.