Consider the following premises. Michael is a doctor if and only if Jennifer is playing squash. Michael is not a doctor. Can we infer the following from them? If we can, name the inference rule being used: Jennifer is playing squash.
 From the fact that Michael is a doctor if and only if Jennifer is playing squash we can infer that if Jennifer plays squash, then Michael is a doctor via biconditional elimination. Finally, from the fact that if Jennifer plays squash, then Michael is a doctor, and that Michael is not a doctor we can infer that Jennifer is not playing squash via modus tollens, which contradicts that Jennifer is playing squash. Therefore, the answer is no.