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: Susan is listening to a song if and only if Jessica is a lawyer. Susan is listening to a song if and only if John is a poet.
If Susan listens to a song, then Jessica is a lawyer can be inferred via the biconditional elimination rule. If Susan listens to a song, then John is a poet can be inferred via the biconditional elimination rule. If Jessica were a lawyer, then Susan is listening to a song can be inferred via the biconditional elimination rule. If John were a poet, then Susan is listening to a song can be inferred via the biconditional elimination rule.