What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: forall x_4: W(x_4) or U(x_4). forall x_4: W(x_4) -> S(x_4). exists x_4: S(x_4) -> Q_1(x_4). forall x_4: U(x_4) -> S(x_4).
exists x_4: W(x_4) -> Q_1(x_4) can be inferred via the existential transitivity rule. exists x_4: U(x_4) -> Q_1(x_4) can be inferred via the existential transitivity rule. forall x_4: S(x_4) can be inferred via the universal disjunction elimination rule.