Consider the following premises. For all x_8, if x_8 climbs a mountain, then x_8 is drinking water. Barbara is climbing a mountain or Linda is sad. For all x_8, if x_8 drinks water, then x_8 is climbing a mountain. Barbara is not drinking water. Can we infer the following from them? Linda is sad.
 From the fact that for all x_8, if x_8 drinks water, then x_8 is climbing a mountain, and that for all x_8, if x_8 climbs a mountain, then x_8 is drinking water we can infer that for all x_8, x_8 will drink water if and only if x_8 will climb a mountain. From the fact that for all x_8, x_8 will drink water if and only if x_8 will climb a mountain we can infer that Barbara is drinking water if and only if Barbara is climbing a mountain. From the fact that Barbara is drinking water if and only if Barbara is climbing a mountain, and that Barbara is not drinking water we can infer that Barbara is not climbing a mountain. Finally, from the fact that Barbara is climbing a mountain or Linda is sad, and that Barbara is not climbing a mountain we can infer that Linda is sad. Therefore, the answer is yes.