Consider the following premises. For all x_11, if x_11 takes a plane, then x_11 is a janitor. For all x_11, if x_11 were a mechanic, then x_11 is taking a plane. For all x_11, if x_11 listens to a song, then x_11 is a mechanic. For all x_11, x_11 will take a plane or x_11 is not a janitor. There is at least one x_11 for which x_11 will listen to a song or x_11 is a janitor. Can we infer the following from them? For all x_11, x_11 will not take a plane.
 From the fact that for all x_11, x_11 will take a plane or x_11 is not a janitor we can infer that for all x_11, if x_11 were a janitor, then x_11 is taking a plane. From the fact that for all x_11, if x_11 listens to a song, then x_11 is a mechanic, and that for all x_11, if x_11 were a mechanic, then x_11 is taking a plane we can infer that for all x_11, if x_11 listens to a song, then x_11 is taking a plane. From the fact that for all x_11, if x_11 were a janitor, then x_11 is taking a plane, and that for all x_11, if x_11 takes a plane, then x_11 is a janitor we can infer that for all x_11, x_11 is a janitor if and only if x_11 will take a plane. From the fact that for all x_11, x_11 is a janitor if and only if x_11 will take a plane we can infer that for all x_11, if x_11 were a janitor, then x_11 is taking a plane. Finally, from the fact that for all x_11, if x_11 listens to a song, then x_11 is taking a plane, that for all x_11, if x_11 were a janitor, then x_11 is taking a plane, and that there is at least one x_11 for which x_11 will listen to a song or x_11 is a janitor we can infer that there is at least one x_11 for which x_11 will take a plane, which contradicts that For all x_11, x_11 will not take a plane. Therefore, the answer is no.