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, if x_4 takes a plane, then x_4 is driving a car. For all x_4, if x_4 were a bartender, then x_4 is curious. For all x_4, if x_4 drives a car, then x_4 is a bartender. There is at least one x_4 for which x_4 is rich or x_4 will drive a car. For all x_4, if x_4 were rich, then x_4 is curious. For all x_4, if x_4 were a bartender, then x_4 is taking a plane.
For all x_4, if x_4 takes a plane, then x_4 is a bartender can be inferred via the universal transitivity rule. For all x_4, if x_4 drives a car, then x_4 is curious can be inferred via the universal transitivity rule. For all x_4, if x_4 drives a car, then x_4 is taking a plane can be inferred via the universal transitivity rule. For all x_4, if x_4 were a bartender, then x_4 is driving a car can be inferred via the universal transitivity rule.