Consider the following premises. For all x_11, if x_11 were bored, then x_11 is an astronaut. For all x_11, x_11 is a musician or x_11 is a server. For all x_11, x_11 will take a plane or x_11 is bored. For all x_11, x_11 is not a musician. There is at least one x_11 for which if x_11 takes a plane, then x_11 is an astronaut. Can we infer the following from them? If we can, name the inference rule being used: For all x_11, either x_11 is a server or x_11 is an astronaut are not true.
 From the fact that for all x_11, x_11 is a musician or x_11 is a server, and that for all x_11, x_11 is not a musician we can infer that for all x_11, x_11 is a server via universal disjunctive syllogism. From the fact that there is at least one x_11 for which if x_11 takes a plane, then x_11 is an astronaut, that for all x_11, if x_11 were bored, then x_11 is an astronaut, and that for all x_11, x_11 will take a plane or x_11 is bored we can infer that there is at least one x_11 for which x_11 is an astronaut via existential disjunction elimination. Finally, from the fact that for all x_11, x_11 is a server, and that there is at least one x_11 for which x_11 is an astronaut we can infer that there is at least one x_11 for which x_11 is a server and x_11 is an astronaut via existential conjunction, which contradicts that For all x_11, either x_11 is a server or x_11 is an astronaut are not true. Therefore, the answer is no.