What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is snowing if and only if it is windy. It is not windy. Mary is not rich. If it is overcast, then Mary is rich.
It is not overcast. It is not windy and Mary is not rich. Mary is not rich and it is not windy. If it snows, then it is windy. If it is windy, then it is snowing. It is not snowing.