Consider the following premises. It is overcast. If it is overcast, then it is late. For all x_20, x_20 will play tennis and x_20 will climb a mountain. Can we infer the following from them? If we can, name the inference rule being used: James is not playing tennis.
 From the fact that for all x_20, x_20 will play tennis and x_20 will climb a mountain we can infer that James is playing tennis and James is climbing a mountain via universal instantiation. From the fact that if it is overcast, then it is late, and that it is overcast we can infer that it is late via modus ponens. Finally, from the fact that James is playing tennis and James is climbing a mountain we can infer that James is playing tennis via simplification, which contradicts that James is not playing tennis. Therefore, the answer is no.