What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z_1: P(z_1) -> U(z_1). forall z_1: U(z_1) -> P(z_1). forall z_1: ~S_3(z_1). forall z_1: U(z_1) -> S_3(z_1).
forall z_1: ~U(z_1). forall z_1: P(z_1) -> S_3(z_1). forall z_1: P(z_1) <-> U(z_1). forall z_1: U(z_1) <-> P(z_1).