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_11: P_11(x_11) or R_1(x_11). forall x_11: Q_1(x_11) or Q_6(x_11). forall x_11: Q_6(x_11) -> S_1(x_11). forall x_11: Q_1(x_11) -> S_1(x_11). exists x_11: ~P_11(x_11).
exists x_11: R_1(x_11) can be inferred via the existential disjunctive syllogism rule. forall x_11: S_1(x_11) can be inferred via the universal disjunction elimination rule.