What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: U_1(x) or ~R_3(x). forall x: U(x) -> R(x). exists x: U_1(x) -> U(x).
exists x: U_1(x) -> R(x). forall x: R_3(x) -> U_1(x).