Consider the following premises. Charles is not happy or it is cold. For all x_3, if x_3 takes a plane, then x_3 is playing tennis. For all x_3, x_3 will not take a plane. Charles is happy or Jessica is playing tennis. For all x_3, if x_3 plays tennis, then x_3 is taking a plane. Can we infer the following from them? If we can, name the inference rule being used: It is cold.
 From the fact that for all x_3, if x_3 plays tennis, then x_3 is taking a plane, and that for all x_3, if x_3 takes a plane, then x_3 is playing tennis we can infer that for all x_3, x_3 will play tennis if and only if x_3 will take a plane via universal biconditional introduction. From the fact that for all x_3, x_3 will play tennis if and only if x_3 will take a plane, and that for all x_3, x_3 will not take a plane we can infer that for all x_3, x_3 will not play tennis via universal biconditional elimination. From the fact that for all x_3, x_3 will not play tennis we can infer that Jessica is not playing tennis via universal instantiation. From the fact that Charles is happy or Jessica is playing tennis, and that Charles is not happy or it is cold we can infer that Jessica is playing tennis or it is cold via resolution. Finally, from the fact that Jessica is playing tennis or it is cold, and that Jessica is not playing tennis we can infer that it is cold via disjunctive syllogism. Therefore, the answer is yes.