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: Linda is playing tennis if and only if Sarah is a janitor. Sarah is a janitor if and only if Linda is playing tennis.
If Linda plays tennis, then Sarah is a janitor can be inferred via the biconditional elimination rule. If Sarah were a janitor, then Linda is playing tennis can be inferred via the biconditional elimination rule. If Sarah were a janitor, then Linda is playing tennis can be inferred via the biconditional elimination rule. If Linda plays tennis, then Sarah is a janitor can be inferred via the biconditional elimination rule.