Consider the following premises. It is snowing if and only if Barbara is excited. It is snowing or Barbara is not excited. Can we infer the following from them? If we can, name the inference rule being used: The fact that it snows does not imply that Barbara is excited.
 From the fact that it is snowing or Barbara is not excited we can infer that if Barbara were excited, then it is snowing via rewriting. Finally, from the fact that it is snowing if and only if Barbara is excited we can infer that if it snows, then Barbara is excited via biconditional elimination, which contradicts that The fact that it snows does not imply that Barbara is excited. Therefore, the answer is no.