What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If William were an astronaut, then Robert is driving a car. If Robert drives a car, then it is snowing. If Richard were a scientist, then William is an astronaut. It is not snowing.
Robert is not driving a car. If William were an astronaut, then it is snowing. If Richard were a scientist, then Robert is driving a car.