Consider the following premises. For all x_15, x_15 is an electrician or x_15 will not play tennis. For all x_15, x_15 will play tennis. Can we infer the following from them? If we can, name the inference rule being used: Michael is an electrician or Thomas is taking a plane.
 From the fact that for all x_15, x_15 is an electrician or x_15 will not play tennis we can infer that for all x_15, if x_15 plays tennis, then x_15 is an electrician via universal rewriting. From the fact that for all x_15, if x_15 plays tennis, then x_15 is an electrician, and that for all x_15, x_15 will play tennis we can infer that for all x_15, x_15 is an electrician via universal modus ponens. From the fact that for all x_15, x_15 is an electrician we can infer that Michael is an electrician via universal instantiation. Finally, from the fact that Michael is an electrician we can infer that Michael is an electrician or Thomas is taking a plane via addition. Therefore, the answer is yes.