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_4, x_4 will drive a car or x_4 is poor. For all x_4, x_4 is not poor or x_4 will take a plane. For all x_4, x_4 will not drive a car or x_4 will sleep. For all x_4, x_4 will not sleep.
For all x_4, x_4 is poor or x_4 will sleep can be inferred via the universal resolution rule.