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: Karen is listening to a song if and only if John is playing squash. David is not climbing a mountain. John is playing squash if and only if Michael is a nurse. Karen is listening to a song if and only if David is climbing a mountain.
If Karen listens to a song, then John is playing squash can be inferred via the biconditional elimination rule. If John plays squash, then Michael is a nurse can be inferred via the biconditional elimination rule. If Karen listens to a song, then David is climbing a mountain can be inferred via the biconditional elimination rule. If John plays squash, then Karen is listening to a song can be inferred via the biconditional elimination rule. If Michael were a nurse, then John is playing squash can be inferred via the biconditional elimination rule. If David climbs a mountain, then Karen is listening to a song can be inferred via the biconditional elimination rule. Karen is not listening to a song can be inferred via the biconditional elimination rule.