Consider the following premises. If Jennifer were curious, then Karen is a janitor. It is cloudy or Jennifer is curious. Karen is a janitor if and only if Charles is a sailor. It is not cloudy or Charles is a sailor. Can we infer the following from them? Karen is not a janitor.
 From the fact that it is cloudy or Jennifer is curious, and that it is not cloudy or Charles is a sailor we can infer that Jennifer is curious or Charles is a sailor. From the fact that Karen is a janitor if and only if Charles is a sailor we can infer that if Charles were a sailor, then Karen is a janitor. Finally, from the fact that if Jennifer were curious, then Karen is a janitor, that if Charles were a sailor, then Karen is a janitor, and that Jennifer is curious or Charles is a sailor we can infer that Karen is a janitor, which contradicts that Karen is not a janitor. Therefore, the answer is no.