What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y_1: R_4(y_1) -> U(y_1). forall y_1: U(y_1) <-> R_4(y_1). forall y_1: U(y_1) or ~R_4(y_1).
forall y_1: R_4(y_1) -> U(y_1). forall y_1: U(y_1) -> R_4(y_1). forall y_1: R_4(y_1) -> U(y_1).