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) -> R_1(x). exists x: R_3(x) -> R_1(x). forall x: R_1(x) -> R(x). forall x: R_1(x) -> R_3(x).
forall x: R(x) -> R_3(x). exists x: R_3(x) -> R(x). forall x: R(x) <-> R_1(x). forall x: R_1(x) <-> R(x). exists x: R_3(x) <-> R_1(x). exists x: R_1(x) <-> R_3(x).