What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_10, if x_10 were sad, then x_10 is driving a car. For all x_10, if x_10 drives a car, then x_10 is sad. For all x_10, x_10 will drive a car if and only if x_10 is sad.
For all x_10, x_10 is sad if and only if x_10 will drive a car. For all x_10, x_10 will drive a car if and only if x_10 is sad. For all x_10, if x_10 drives a car, then x_10 is sad. For all x_10, if x_10 were sad, then x_10 is driving a car.