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_8, x_8 is not a taxi driver. For all x_8, x_8 is excited. For all x_8, x_8 is a server or x_8 will drive a car. For all x_8, if x_8 were a server, then x_8 is a taxi driver.
For all x_8, x_8 is not a server can be inferred via the universal modus tollens rule.