Consider the following premises. For all x_17, if x_17 were a janitor, then x_17 is not taking a plane. For all x_17, if x_17 plays a game, then x_17 is an artist. For all x_17, x_17 is a janitor if and only if x_17 will play a game. There is at least one x_17 for which x_17 will take a plane. For all x_17, if x_17 were an artist, then x_17 is playing a game. Can we infer the following from them? There is at least one x_17 for which x_17 is not an artist.
 From the fact that for all x_17, if x_17 plays a game, then x_17 is an artist, and that for all x_17, if x_17 were an artist, then x_17 is playing a game we can infer that for all x_17, x_17 will play a game if and only if x_17 is an artist. From the fact that for all x_17, if x_17 were a janitor, then x_17 is not taking a plane, and that there is at least one x_17 for which x_17 will take a plane we can infer that there is at least one x_17 for which x_17 is not a janitor. From the fact that for all x_17, x_17 is a janitor if and only if x_17 will play a game, and that there is at least one x_17 for which x_17 is not a janitor we can infer that there is at least one x_17 for which x_17 will not play a game. Finally, from the fact that for all x_17, x_17 will play a game if and only if x_17 is an artist, and that there is at least one x_17 for which x_17 will not play a game we can infer that there is at least one x_17 for which x_17 is not an artist. Therefore, the answer is yes.