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: p -> q. q <-> p. ~q.
~p can be inferred via the modus tollens rule. q -> p can be inferred via the biconditional elimination rule. p -> q can be inferred via the biconditional elimination rule. ~p can be inferred via the biconditional elimination rule.