What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? William is climbing a mountain if and only if Richard is a doctor. It is cold if and only if it is windy. William is not climbing a mountain. It is not cold.
William is not climbing a mountain and it is not cold. It is not cold and William is not climbing a mountain. If William climbs a mountain, then Richard is a doctor. If it is cold, then it is windy. If Richard were a doctor, then William is climbing a mountain. If it is windy, then it is cold. Richard is not a doctor. It is not windy.