Consider the following premises. For all x_2, x_2 is an electrician or x_2 will play tennis. There is at least one x_2 for which if x_2 were sad, then x_2 is not playing tennis. For all x_2, x_2 is not an electrician. Can we infer the following from them? If we can, name the inference rule being used: For all x_2, x_2 is sad.
 From the fact that for all x_2, x_2 is an electrician or x_2 will play tennis, and that for all x_2, x_2 is not an electrician we can infer that for all x_2, x_2 will play tennis via universal disjunctive syllogism. Finally, from the fact that there is at least one x_2 for which if x_2 were sad, then x_2 is not playing tennis, and that for all x_2, x_2 will play tennis we can infer that there is at least one x_2 for which x_2 is not sad via existential modus tollens, which contradicts that For all x_2, x_2 is sad. Therefore, the answer is no.