What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: Thomas is listening to a song if and only if it is raining. It is raining. If Thomas listens to a song, then it is raining.
If Thomas listens to a song, then it is raining can be inferred via the biconditional elimination rule. If it rains, then Thomas is listening to a song can be inferred via the biconditional elimination rule.