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: For all x_2, x_2 will not sleep. For all x_2, x_2 will sleep or x_2 is excited. For all x_2, if x_2 cooks, then x_2 is not excited.
For all x_2, x_2 is excited can be inferred via the universal disjunctive syllogism rule.