Consider the following premises. For all x_9, x_9 is a politician or x_9 is not a lawyer. For all x_9, x_9 is sad. For all x_9, if x_9 takes a plane, then x_9 is a lawyer. For all x_9, x_9 will take a plane. Can we infer the following from them? If we can, name the inference rule being used: For all x_9, x_9 is sad and x_9 is a politician.
 From the fact that for all x_9, if x_9 takes a plane, then x_9 is a lawyer, and that for all x_9, x_9 will take a plane we can infer that for all x_9, x_9 is a lawyer via universal modus ponens. From the fact that for all x_9, x_9 is a politician or x_9 is not a lawyer we can infer that for all x_9, if x_9 were a lawyer, then x_9 is a politician via universal rewriting. From the fact that for all x_9, if x_9 were a lawyer, then x_9 is a politician, and that for all x_9, x_9 is a lawyer we can infer that for all x_9, x_9 is a politician via universal modus ponens. Finally, from the fact that for all x_9, x_9 is sad, and that for all x_9, x_9 is a politician we can infer that for all x_9, x_9 is sad and x_9 is a politician via universal conjunction. Therefore, the answer is yes.