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_15: Q_15(x_15). forall x_15: P_15(x_15) or Q_11(x_15). p -> ~Q_11(a_9). forall x_15: P_15(x_15) -> ~Q_15(x_15).
forall x_15: ~P_15(x_15) can be inferred via the universal modus tollens rule.