What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_17, if x_17 drives a car, then x_17 is working. If Mary works, then Joseph is reading a book. Mary is not driving a car. Joseph is reading a book if and only if Mary is driving a car.
If Joseph reads a book, then Mary is driving a car. If Mary drives a car, then Joseph is reading a book.