What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one y_4 for which y_4 will not make tea. For all y_4, y_4 will drive a car if and only if y_4 will make tea.
For all y_4, if y_4 drives a car, then y_4 is making tea. For all y_4, if y_4 makes tea, then y_4 is driving a car. There is at least one y_4 for which y_4 will not drive a car.