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 z_4, if z_4 were a sailor, then z_4 is rich. There is at least one z_4 for which z_4 will drive a car or z_4 is fast. For all z_4, if z_4 were fast, then z_4 is a sailor. For all z_4, z_4 is rich if and only if z_4 will drive a car.
For all z_4, if z_4 were fast, then z_4 is rich can be inferred via the universal transitivity rule. For all z_4, if z_4 were rich, then z_4 is driving a car can be inferred via the universal biconditional elimination rule. For all z_4, if z_4 drives a car, then z_4 is rich can be inferred via the universal biconditional elimination rule.