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_17: P_17(x_17) -> Q_17(x_17). forall x_17: Q_17(x_17) -> P_17(x_17). q_11. Q_17(a_16) -> ~q_11.
~Q_17(a_16) can be inferred via the modus tollens rule. forall x_17: P_17(x_17) <-> Q_17(x_17) can be inferred via the universal biconditional introduction rule. forall x_17: Q_17(x_17) <-> P_17(x_17) can be inferred via the universal biconditional introduction rule.