Consider the following premises. For all x_11, x_11 will climb a mountain if and only if x_11 will cook. For all x_11, x_11 will cook if and only if x_11 will climb a mountain. Can we infer the following from them? If Robert climbs a mountain, then Robert is cooking.
 From the fact that for all x_11, x_11 will cook if and only if x_11 will climb a mountain we can infer that for all x_11, if x_11 climbs a mountain, then x_11 is cooking. From the fact that for all x_11, x_11 will climb a mountain if and only if x_11 will cook we can infer that for all x_11, if x_11 cooks, then x_11 is climbing a mountain. From the fact that for all x_11, if x_11 climbs a mountain, then x_11 is cooking, and that for all x_11, if x_11 cooks, then x_11 is climbing a mountain we can infer that for all x_11, x_11 will climb a mountain if and only if x_11 will cook. From the fact that for all x_11, x_11 will climb a mountain if and only if x_11 will cook we can infer that Robert is climbing a mountain if and only if Robert is cooking. Finally, from the fact that Robert is climbing a mountain if and only if Robert is cooking we can infer that if Robert climbs a mountain, then Robert is cooking. Therefore, the answer is yes.