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: forall x_3: P_3(x_3) -> P_1(x_3). exists x_3: ~Q_3(x_3). forall x_3: P_1(x_3) -> P_3(x_3). forall x_3: P_3(x_3) -> Q_3(x_3).
exists x_3: ~P_3(x_3) can be inferred via the existential modus tollens rule. forall x_3: P_1(x_3) -> Q_3(x_3) can be inferred via the universal transitivity rule. forall x_3: P_3(x_3) <-> P_1(x_3) can be inferred via the universal biconditional introduction rule. forall x_3: P_1(x_3) <-> P_3(x_3) can be inferred via the universal biconditional introduction rule.