Consider the following premises. If it is windy, then Elisabeth is a lawyer. It is windy or it is not sunny. It is sunny or Elisabeth is not a lawyer. Can we infer the following from them? If we can, name the inference rule being used: If is not true that Elisabeth is a lawyer if and only if it is sunny.
 From the fact that it is windy or it is not sunny we can infer that if it is sunny, then it is windy via rewriting. From the fact that it is sunny or Elisabeth is not a lawyer we can infer that if Elisabeth were a lawyer, then it is sunny via rewriting. From the fact that if it is sunny, then it is windy, and that if it is windy, then Elisabeth is a lawyer we can infer that if it is sunny, then Elisabeth is a lawyer via transitivity. Finally, from the fact that if Elisabeth were a lawyer, then it is sunny, and that if it is sunny, then Elisabeth is a lawyer we can infer that Elisabeth is a lawyer if and only if it is sunny via biconditional introduction, which contradicts that If is not true that Elisabeth is a lawyer if and only if it is sunny. Therefore, the answer is no.