Consider the following premises. It is not raining. If Patricia works, then it is raining. It is raining if and only if it is sunny. If it is sunny, then Patricia is working. Can we infer the following from them? Patricia is working.
 From the fact that it is raining if and only if it is sunny we can infer that if it rains, then it is sunny. From the fact that if it rains, then it is sunny, and that if it is sunny, then Patricia is working we can infer that if it rains, then Patricia is working. From the fact that if Patricia works, then it is raining, and that if it rains, then Patricia is working we can infer that Patricia is working if and only if it is raining. Finally, from the fact that Patricia is working if and only if it is raining, and that it is not raining we can infer that Patricia is not working, which contradicts that Patricia is working. Therefore, the answer is no.