Consider the following premises. For all z_3, z_3 is a nurse if and only if z_3 is poor. For all z_3, z_3 is a nurse or z_3 is not poor. Can we infer the following from them? If we can, name the inference rule being used: For all z_3, z_3 is a nurse if and only if z_3 is poor.
That is one of the premises. Therefore, the answer is yes.