What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, if y drives a car, then y is playing tennis. For all y, if y works, then y is driving a car. For all y, if y plays tennis, then y is working. There is at least one y for which if y writes a letter, then y is working.
For all y, if y drives a car, then y is working. For all y, if y works, then y is playing tennis. For all y, if y plays tennis, then y is driving a car. There is at least one y for which if y writes a letter, then y is driving a car.