What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Susan is an electrician if and only if it is windy. It is raining. If David were a sailor, then it is not raining. If Susan were an electrician, then David is a sailor.
David is not a sailor. If Susan were an electrician, then it is windy. If it is windy, then Susan is an electrician.