Consider the following premises. For all x_12, if x_12 reads a book, then x_12 is happy. Richard is not happy. For all x_12, if x_12 were happy, then x_12 is reading a book. Richard is running. Can we infer the following from them? If we can, name the inference rule being used: Richard is running and Richard is not reading a book.
 From the fact that for all x_12, if x_12 reads a book, then x_12 is happy, and that for all x_12, if x_12 were happy, then x_12 is reading a book we can infer that for all x_12, x_12 will read a book if and only if x_12 is happy via universal biconditional introduction. From the fact that for all x_12, x_12 will read a book if and only if x_12 is happy we can infer that Richard is reading a book if and only if Richard is happy via universal instantiation. From the fact that Richard is reading a book if and only if Richard is happy, and that Richard is not happy we can infer that Richard is not reading a book via biconditional elimination. Finally, from the fact that Richard is running, and that Richard is not reading a book we can infer that Richard is running and Richard is not reading a book via conjunction. Therefore, the answer is yes.