Consider the following premises. For all x_10, x_10 will not go running. Jessica is climbing a mountain if and only if Robert is playing tennis. For all x_10, if x_10 climbs a mountain, then x_10 is running. For all x_10, if x_10 goes running, then x_10 is climbing a mountain. Can we infer the following from them? Robert is playing tennis.
 From the fact that for all x_10, if x_10 goes running, then x_10 is climbing a mountain, and that for all x_10, if x_10 climbs a mountain, then x_10 is running we can infer that for all x_10, x_10 will go running if and only if x_10 will climb a mountain. From the fact that for all x_10, x_10 will go running if and only if x_10 will climb a mountain, and that for all x_10, x_10 will not go running we can infer that for all x_10, x_10 will not climb a mountain. From the fact that for all x_10, x_10 will not climb a mountain we can infer that Jessica is not climbing a mountain. Finally, from the fact that Jessica is climbing a mountain if and only if Robert is playing tennis, and that Jessica is not climbing a mountain we can infer that Robert is not playing tennis, which contradicts that Robert is playing tennis. Therefore, the answer is no.