What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is late if and only if Mary is driving a car. It is cold. Mary is not driving a car. If it is not late, then it is raining.
It is cold and Mary is not driving a car. Mary is not driving a car and it is cold. If it is late, then Mary is driving a car. If Mary drives a car, then it is late. It is not late.