Consider the following premises. Richard is not a taxi driver. Barbara is drinking water if and only if Mary is a police officer. It is overcast. If Barbara drinks water, then Richard is a taxi driver. Can we infer the following from them? Mary is a police officer.
 From the fact that if Barbara drinks water, then Richard is a taxi driver, and that Richard is not a taxi driver we can infer that Barbara is not drinking water. Finally, from the fact that Barbara is drinking water if and only if Mary is a police officer, and that Barbara is not drinking water we can infer that Mary is not a police officer, which contradicts that Mary is a police officer. Therefore, the answer is no.