Consider the following premises. For all x_3, x_3 will write a letter and x_3 is bored. For all x_3, x_3 will take a plane. Can we infer the following from them? If we can, name the inference rule being used: For all x_3, x_3 will take a plane and x_3 will write a letter.
 From the fact that for all x_3, x_3 will write a letter and x_3 is bored we can infer that for all x_3, x_3 will write a letter via universal simplification. Finally, from the fact that for all x_3, x_3 will take a plane, and that for all x_3, x_3 will write a letter we can infer that for all x_3, x_3 will take a plane and x_3 will write a letter via universal conjunction. Therefore, the answer is yes.