Consider the following premises. For all y_1, y_1 is not fast. Susan is an electrician if and only if William is climbing a mountain. For all y_1, y_1 is fast if and only if y_1 will climb a mountain. Can we infer the following from them? Susan is not an electrician or it is windy.
 From the fact that for all y_1, y_1 is fast if and only if y_1 will climb a mountain, and that for all y_1, y_1 is not fast we can infer that for all y_1, y_1 will not climb a mountain. From the fact that for all y_1, y_1 will not climb a mountain we can infer that William is not climbing a mountain. From the fact that Susan is an electrician if and only if William is climbing a mountain, and that William is not climbing a mountain we can infer that Susan is not an electrician. Finally, from the fact that Susan is not an electrician we can infer that Susan is not an electrician or it is windy. Therefore, the answer is yes.