Consider the following premises. For all x_11, x_11 will not take a plane. For all x_11, x_11 is bored or x_11 will not climb a mountain. For all x_11, if x_11 were a sailor, then x_11 is climbing a mountain. For all x_11, x_11 will take a plane if and only if x_11 is a sailor. For all x_11, if x_11 were bored, then x_11 is a sailor. Can we infer the following from them? There is at least one x_11 for which x_11 is bored.
 From the fact that for all x_11, x_11 is bored or x_11 will not climb a mountain we can infer that for all x_11, if x_11 climbs a mountain, then x_11 is bored. From the fact that for all x_11, if x_11 were a sailor, then x_11 is climbing a mountain, and that for all x_11, if x_11 climbs a mountain, then x_11 is bored we can infer that for all x_11, if x_11 were a sailor, then x_11 is bored. From the fact that for all x_11, x_11 will take a plane if and only if x_11 is a sailor, and that for all x_11, x_11 will not take a plane we can infer that for all x_11, x_11 is not a sailor. From the fact that for all x_11, if x_11 were a sailor, then x_11 is bored, and that for all x_11, if x_11 were bored, then x_11 is a sailor we can infer that for all x_11, x_11 is a sailor if and only if x_11 is bored. Finally, from the fact that for all x_11, x_11 is a sailor if and only if x_11 is bored, and that for all x_11, x_11 is not a sailor we can infer that for all x_11, x_11 is not bored, which contradicts that There is at least one x_11 for which x_11 is bored. Therefore, the answer is no.