What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is not snowing. James is taking a plane. If Linda were a doctor, then it is snowing. Linda is a doctor if and only if it is snowing.
Linda is not a doctor. It is not snowing and James is taking a plane. James is taking a plane and it is not snowing. If Linda were a doctor, then it is snowing. If it snows, then Linda is a doctor. Linda is not a doctor.