Consider the following premises. It is not overcast. If it is overcast, then James is fast. If it is overcast, then James is fast. If James were fast, then it is overcast. Can we infer the following from them? James is fast.
 From the fact that if James were fast, then it is overcast, and that if it is overcast, then James is fast we can infer that James is fast if and only if it is overcast. From the fact that James is fast if and only if it is overcast we can infer that if James were fast, then it is overcast. From the fact that if James were fast, then it is overcast, and that if it is overcast, then James is fast we can infer that James is fast if and only if it is overcast. Finally, from the fact that James is fast if and only if it is overcast, and that it is not overcast we can infer that James is not fast, which contradicts that James is fast. Therefore, the answer is no.