Consider the following premises. For all x_5, if x_5 were an electrician, then x_5 is taking a plane. There is at least one x_5 for which if x_5 were a sailor, then x_5 is sleeping. For all x_5, if x_5 sleeps, then x_5 is sad. For all x_5, if x_5 were sad, then x_5 is an electrician. Can we infer the following from them? There is at least one x_5 for which if x_5 were a sailor, then x_5 is taking a plane.
 From the fact that there is at least one x_5 for which if x_5 were a sailor, then x_5 is sleeping, and that for all x_5, if x_5 sleeps, then x_5 is sad we can infer that there is at least one x_5 for which if x_5 were a sailor, then x_5 is sad. From the fact that for all x_5, if x_5 were sad, then x_5 is an electrician, and that for all x_5, if x_5 were an electrician, then x_5 is taking a plane we can infer that for all x_5, if x_5 were sad, then x_5 is taking a plane. Finally, from the fact that there is at least one x_5 for which if x_5 were a sailor, then x_5 is sad, and that for all x_5, if x_5 were sad, then x_5 is taking a plane we can infer that there is at least one x_5 for which if x_5 were a sailor, then x_5 is taking a plane. Therefore, the answer is yes.