Consider the following premises. David is a musician or it is raining. Mary is a lawyer or David is not a musician. It is raining if and only if Mary is a lawyer. Can we infer the following from them? Mary is not a lawyer.
 From the fact that Mary is a lawyer or David is not a musician we can infer that if David were a musician, then Mary is a lawyer. From the fact that it is raining if and only if Mary is a lawyer we can infer that if it rains, then Mary is a lawyer. Finally, from the fact that if David were a musician, then Mary is a lawyer, that if it rains, then Mary is a lawyer, and that David is a musician or it is raining we can infer that Mary is a lawyer, which contradicts that Mary is not a lawyer. Therefore, the answer is no.