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: exists x_5: Q_1(x_5). forall x_5: U_1(x_5) -> Q_5(x_5). forall x_5: U_1(x_5) or R(x_5). forall x_5: ~Q_5(x_5).
forall x_5: ~U_1(x_5) can be inferred via the universal modus tollens rule.