What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, x_9 is a taxi driver if and only if x_9 will play tennis. For all x_9, if x_9 plays tennis, then x_9 is a taxi driver. For all x_9, if x_9 plays tennis, then x_9 is a taxi driver.
For all x_9, if x_9 were a taxi driver, then x_9 is playing tennis. For all x_9, if x_9 plays tennis, then x_9 is a taxi driver.