What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: R(x) or R_3(x). exists x: ~R(x) or P(x). forall x: P(x) -> P_2(x). forall x: P_2(x) or ~R_3(x). forall x: P_2(x) -> P(x).
exists x: R_3(x) or P(x). forall x: R_3(x) -> P_2(x). forall x: P(x) <-> P_2(x). forall x: P_2(x) <-> P(x).