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: If it snows, then Joseph is listening to a song. Jennifer is a police officer if and only if it is snowing. Joseph is not listening to a song.
It is not snowing can be inferred via the modus tollens rule. If Jennifer were a police officer, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then Jennifer is a police officer can be inferred via the biconditional elimination rule.