Consider the following premises. For all x_18, x_18 is an electrician if and only if x_18 will take a plane. For all x_18, x_18 will not take a plane. For all x_18, x_18 is an electrician or x_18 is a lawyer. 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 lawyer or x_1 will work.
 From the fact that for all x_18, x_18 is an electrician if and only if x_18 will take a plane, and that for all x_18, x_18 will not take a plane we can infer that for all x_18, x_18 is not an electrician via universal biconditional elimination. From the fact that for all x_18, x_18 is an electrician or x_18 is a lawyer, and that for all x_18, x_18 is not an electrician we can infer that for all x_18, x_18 is a lawyer via universal disjunctive syllogism. From the fact that for all x_18, x_18 is a lawyer we can infer that Richard is a lawyer via universal instantiation. From the fact that Richard is a lawyer we can infer that there is at least one x_1 for which x_1 is a lawyer via existential generalization. Finally, from the fact that there is at least one x_1 for which x_1 is a lawyer we can infer that there is at least one x_1 for which x_1 is a lawyer or x_1 will work via existential addition. Therefore, the answer is yes.