Consider the following premises. For all x_12, x_12 will listen to a song. For all x_12, x_12 is an electrician if and only if x_12 will read a book. There is at least one x_12 for which x_12 is an electrician. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_12 for which x_12 will read a book and x_12 will listen to a song.
 From the fact that for all x_12, x_12 is an electrician if and only if x_12 will read a book we can infer that for all x_12, if x_12 were an electrician, then x_12 is reading a book via universal biconditional elimination. From the fact that for all x_12, if x_12 were an electrician, then x_12 is reading a book, and that there is at least one x_12 for which x_12 is an electrician we can infer that there is at least one x_12 for which x_12 will read a book via existential modus ponens. Finally, from the fact that there is at least one x_12 for which x_12 will read a book, and that for all x_12, x_12 will listen to a song we can infer that there is at least one x_12 for which x_12 will read a book and x_12 will listen to a song via existential conjunction. Therefore, the answer is yes.