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: exists x_3: P_3(x_3) -> ~Q_3(x_3). forall x_3: Q_3(x_3). forall x_3: S(x_3) <-> P_3(x_3).
exists x_3: ~P_3(x_3) can be inferred via the existential modus tollens rule. forall x_3: S(x_3) -> P_3(x_3) can be inferred via the universal biconditional elimination rule. forall x_3: P_3(x_3) -> S(x_3) can be inferred via the universal biconditional elimination rule.