What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_3: U_1(x_3) <-> S(x_3). forall x_3: P(x_3) <-> U_1(x_3). exists x_3: ~P(x_3).
forall x_3: U_1(x_3) -> S(x_3). forall x_3: P(x_3) -> U_1(x_3). forall x_3: S(x_3) -> U_1(x_3). forall x_3: U_1(x_3) -> P(x_3). exists x_3: ~U_1(x_3).