Consider the following premises. For all x_7, x_7 will work if and only if x_7 is a taxi driver. For all z, z will not cook. Jennifer is a taxi driver if and only if Thomas is cooking. Can we infer the following from them? If we can, name the inference rule being used: Jennifer is not working.
 From the fact that for all z, z will not cook we can infer that Thomas is not cooking via universal instantiation. From the fact that for all x_7, x_7 will work if and only if x_7 is a taxi driver we can infer that Jennifer is working if and only if Jennifer is a taxi driver via universal instantiation. From the fact that Jennifer is a taxi driver if and only if Thomas is cooking, and that Thomas is not cooking we can infer that Jennifer is not a taxi driver via biconditional elimination. Finally, from the fact that Jennifer is working if and only if Jennifer is a taxi driver, and that Jennifer is not a taxi driver we can infer that Jennifer is not working via biconditional elimination. Therefore, the answer is yes.