What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Mary is a doctor if and only if it is windy. Mary is a doctor if and only if it is windy.
If Mary were a doctor, then it is windy. If Mary were a doctor, then it is windy. If it is windy, then Mary is a doctor. If it is windy, then Mary is a doctor.