Consider the following premises. Thomas is climbing a mountain if and only if William is an electrician. Thomas is climbing a mountain or it is cold. For all x_17, x_17 is not an electrician. Can we infer the following from them? If we can, name the inference rule being used: It is late or it is cold.
 From the fact that for all x_17, x_17 is not an electrician we can infer that William is not an electrician via universal instantiation. From the fact that Thomas is climbing a mountain if and only if William is an electrician, and that William is not an electrician we can infer that Thomas is not climbing a mountain via biconditional elimination. From the fact that Thomas is not climbing a mountain we can infer that Thomas is not climbing a mountain or it is late via addition. Finally, from the fact that Thomas is not climbing a mountain or it is late, and that Thomas is climbing a mountain or it is cold we can infer that it is late or it is cold via resolution. Therefore, the answer is yes.