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_11: S_4(x_11) -> Q(x_11). forall x_11: Q(x_11) -> Q_7(x_11). exists x_11: Q(x_11) -> S_4(x_11). forall x_11: ~Q_7(x_11). forall x_11: Q(x_11) -> S_4(x_11).
forall x_11: ~Q(x_11) can be inferred via the universal modus tollens rule. forall x_11: S_4(x_11) -> Q_7(x_11) can be inferred via the universal transitivity rule. forall x_11: S_4(x_11) <-> Q(x_11) can be inferred via the universal biconditional introduction rule. forall x_11: Q(x_11) <-> S_4(x_11) can be inferred via the universal biconditional introduction rule. exists x_11: Q(x_11) <-> S_4(x_11) can be inferred via the existential biconditional introduction rule. exists x_11: S_4(x_11) <-> Q(x_11) can be inferred via the existential biconditional introduction rule.