What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_15: ~Q_15(x_15). exists x_15: S_4(x_15) <-> Q_15(x_15). forall x_15: U(x_15) -> S_4(x_15). forall x_15: U(x_15) <-> T_2(x_15).
forall x_15: U(x_15) -> T_2(x_15). exists x_15: S_4(x_15) -> Q_15(x_15). forall x_15: T_2(x_15) -> U(x_15). exists x_15: Q_15(x_15) -> S_4(x_15). exists x_15: ~S_4(x_15).