Consider the following premises. For all x_18, x_18 will go running if and only if x_18 will drive a car. For all x_18, x_18 will not drive a car. For all x_18, x_18 will go running or x_18 is a poet. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_1 for which x_1 is a poet or x_1 will play a game.
 From the fact that for all x_18, x_18 will go running if and only if x_18 will drive a car, and that for all x_18, x_18 will not drive a car we can infer that for all x_18, x_18 will not go running via universal biconditional elimination. From the fact that for all x_18, x_18 will go running or x_18 is a poet, and that for all x_18, x_18 will not go running we can infer that for all x_18, x_18 is a poet via universal disjunctive syllogism. From the fact that for all x_18, x_18 is a poet we can infer that Robert is a poet via universal instantiation. From the fact that Robert is a poet we can infer that there is at least one x_1 for which x_1 is a poet via existential generalization. Finally, from the fact that there is at least one x_1 for which x_1 is a poet we can infer that there is at least one x_1 for which x_1 is a poet or x_1 will play a game via existential addition. Therefore, the answer is yes.