What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: P(z) <-> P_2(z). ~P_2(a_11). u -> P(a_11). forall z: P_2(z) -> P(z).
forall z: P(z) -> P_2(z). forall z: P_2(z) -> P(z).