Consider the following premises. For all z_4, z_4 will go running if and only if z_4 is a writer. Elisabeth is not a writer. Can we infer the following from them? If we can, name the inference rule being used: Elisabeth is not running.
 From the fact that for all z_4, z_4 will go running if and only if z_4 is a writer we can infer that Elisabeth is running if and only if Elisabeth is a writer via universal instantiation. Finally, from the fact that Elisabeth is running if and only if Elisabeth is a writer, and that Elisabeth is not a writer we can infer that Elisabeth is not running via biconditional elimination. Therefore, the answer is yes.