What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_15, if x_15 plays a game, then x_15 is a doctor. There is at least one x_15 for which x_15 is a taxi driver if and only if x_15 is a doctor. For all x_15, x_15 will play a game if and only if x_15 is a taxi driver.
For all x_15, if x_15 plays a game, then x_15 is a taxi driver. There is at least one x_15 for which if x_15 were a taxi driver, then x_15 is a doctor. For all x_15, if x_15 were a taxi driver, then x_15 is playing a game. There is at least one x_15 for which if x_15 were a doctor, then x_15 is a taxi driver.