Consider the following premises. Susan is curious or John is listening to a song. If John listens to a song, then it is late. It is late if and only if Susan is curious. If it is late, then Susan is curious. Can we infer the following from them? If we can, name the inference rule being used: It is late.
 From the fact that it is late if and only if Susan is curious we can infer that if Susan were curious, then it is late via biconditional elimination. From the fact that if it is late, then Susan is curious, and that if Susan were curious, then it is late we can infer that it is late if and only if Susan is curious via biconditional introduction. From the fact that it is late if and only if Susan is curious we can infer that if Susan were curious, then it is late via biconditional elimination. Finally, from the fact that if Susan were curious, then it is late, that if John listens to a song, then it is late, and that Susan is curious or John is listening to a song we can infer that it is late via disjunction elimination. Therefore, the answer is yes.